Getting Started with Robots for kids and children in STEM this holiday season

Now’s the perfect time to buy your kids/nieces/cousins some robots. Robots are a great way to get children excited about computers. Robots get them stoked in a way that a simple Hello World console app just can’t.

If you’re not careful you can spent hundreds on robots. However, I’m notoriously frugal and I believe that you can build some amazing stuff with children with a reasonable budget.

Here’s some of the robot and electronics kits I recommend and have built with my kids.

4M Tin Can Robot

This is just a teaser but it’s less than a trip to the movies. This silly little kit takes 2 AAA batteries and will take an aluminum can and animate it. It gets kids thinking about using found objects in their robots, as opposed to them thinking custom equipment is always required.

tincan

Quadru-Bot 14-in-1 Solar Robot

One of the challenges is “what age should I start?” and “how complex of a robot can my __ year old handle?” Kits like this are nice because they are starting with batteries and gears and include two levels of building, basic and experienced. It’s also a nice kit because it includes solar power as an option and also can work in water (the bath).

713-IOSBdAL._SL1500_

OWI Robotic Arm Edge

This isn’t a kit but it’s a reasonably priced robotic arm to get kids thinking in terms of command and control and multiple dimensions. OWI also has a cool 3in1 robot RC kit if you prefer driving robots around and more “rebuildability.”

51LAkVypvAL

Mirobot

This Christmas my 7 year old and I built a Mirobot. You can get pre-soldered and solder-yourself kits. We got the main Mirobot Kit PLUS the Addons Kit which includes clever additional modules for Line Following, Sound, and Collision Detection.

The whole Mirobot execution is brilliant. The hardware and software are all open source, so if you want to acquire the parts and make it yourself you can. You can get kits in various levels of preassembly.

It’s built on an Arduino but is preloaded with some very clever software that takes advantage of its onboard Wifi. You can program it in C with Arduino tools, of course, but for kids, they can use JavaScript and an in-browser editor, much like Logo. It will create its own ad-hoc wifi network by default, or you can join it to your home network.

image

The creator is also building an Apps Platform so you can control the Mirobot from other apps within your browser and websocket your way over to the robot.

It took us about a weekend to build and you can see in the pic below that my 7 year old was able to install a pen and get the bot to draw a stickman. He was THRILLED.

10838706_883990588298288_1242836197_n

Edison

This isn’t the Intel Edison, although you can make some great robots with it as well. No, this is Edison, a little LEGO compatible robot from the makers of Microbric, a great robot platform from a few years ago. I actually made a Microbric robot in 2007 and blogged about it.

Edison is fantastic and just $50. If you’re a teacher and can get a multiples pack, you can get them as cheap as $35 each. You program Edison with a clean drag and drop icon system then download the program to your robot with a cable from your computer’s headphone jack.

Out of the box you can have it follow a flashlight/torch, follow lines on paper, fight each other in a sumo ring, avoid walls, and lots more. In this picture there’s two Edison’s stacked on each other. The top one has the wheels removed and replaced with Lego elements to make robot arms.

image

LEGO Mindstorms

OK, yes, LEGO Mindstorms are $350, so that’s not exactly frugal. BUT, I’ve seen parents buy $500 iPads without a thought, why not consider a more tactile and engineering-focused gift for a girl or boy?

This is THE flagship. It’s got Wifi, Bluetooth, color sensors, iPad apps, collision detection, motors galore and unlimited replayability. There’s also a huge online community dedicated to taking Mindstorms to the next level. If you can swing it, it’s worth the money and appropriate for anyone from 6 to 60.

81Hn0H3SyAL._SL1500_

Snap Circuits

I couldn’t love Snap Circuits more. I started with the Jr. Snap Circuits and we eventually graduated to Snap Circuits Pro. They are my #1 go-to gift idea for kids of friends and relatives.

While this isn’t a robotics kit, per se, it really builds the basic understanding of batteries, electronics, and motors that kids will need to move to the next level.

91lfaA93v0L._SL1500_

What robot kids do YOU recommend?


© 2014 Scott Hanselman. All rights reserved.
     

Now's the perfect time to buy your kids/nieces/cousins some robots. Robots are a great way to get children excited about computers. Robots get them stoked in a way that a simple Hello World console app just can't.

If you're not careful you can spent hundreds on robots. However, I'm notoriously frugal and I believe that you can build some amazing stuff with children with a reasonable budget.

Here's some of the robot and electronics kits I recommend and have built with my kids.

4M Tin Can Robot

This is just a teaser but it's less than a trip to the movies. This silly little kit takes 2 AAA batteries and will take an aluminum can and animate it. It gets kids thinking about using found objects in their robots, as opposed to them thinking custom equipment is always required.

tincan

Quadru-Bot 14-in-1 Solar Robot

One of the challenges is "what age should I start?" and "how complex of a robot can my __ year old handle?" Kits like this are nice because they are starting with batteries and gears and include two levels of building, basic and experienced. It's also a nice kit because it includes solar power as an option and also can work in water (the bath).

713-IOSBdAL._SL1500_

OWI Robotic Arm Edge

This isn't a kit but it's a reasonably priced robotic arm to get kids thinking in terms of command and control and multiple dimensions. OWI also has a cool 3in1 robot RC kit if you prefer driving robots around and more "rebuildability."

51LAkVypvAL

Mirobot

This Christmas my 7 year old and I built a Mirobot. You can get pre-soldered and solder-yourself kits. We got the main Mirobot Kit PLUS the Addons Kit which includes clever additional modules for Line Following, Sound, and Collision Detection.

The whole Mirobot execution is brilliant. The hardware and software are all open source, so if you want to acquire the parts and make it yourself you can. You can get kits in various levels of preassembly.

It's built on an Arduino but is preloaded with some very clever software that takes advantage of its onboard Wifi. You can program it in C with Arduino tools, of course, but for kids, they can use JavaScript and an in-browser editor, much like Logo. It will create its own ad-hoc wifi network by default, or you can join it to your home network.

image

The creator is also building an Apps Platform so you can control the Mirobot from other apps within your browser and websocket your way over to the robot.

It took us about a weekend to build and you can see in the pic below that my 7 year old was able to install a pen and get the bot to draw a stickman. He was THRILLED.

10838706_883990588298288_1242836197_n

Edison

This isn't the Intel Edison, although you can make some great robots with it as well. No, this is Edison, a little LEGO compatible robot from the makers of Microbric, a great robot platform from a few years ago. I actually made a Microbric robot in 2007 and blogged about it.

Edison is fantastic and just $50. If you're a teacher and can get a multiples pack, you can get them as cheap as $35 each. You program Edison with a clean drag and drop icon system then download the program to your robot with a cable from your computer's headphone jack.

Out of the box you can have it follow a flashlight/torch, follow lines on paper, fight each other in a sumo ring, avoid walls, and lots more. In this picture there's two Edison's stacked on each other. The top one has the wheels removed and replaced with Lego elements to make robot arms.

image

LEGO Mindstorms

OK, yes, LEGO Mindstorms are $350, so that's not exactly frugal. BUT, I've seen parents buy $500 iPads without a thought, why not consider a more tactile and engineering-focused gift for a girl or boy?

This is THE flagship. It's got Wifi, Bluetooth, color sensors, iPad apps, collision detection, motors galore and unlimited replayability. There's also a huge online community dedicated to taking Mindstorms to the next level. If you can swing it, it's worth the money and appropriate for anyone from 6 to 60.

81Hn0H3SyAL._SL1500_

Snap Circuits

I couldn't love Snap Circuits more. I started with the Jr. Snap Circuits and we eventually graduated to Snap Circuits Pro. They are my #1 go-to gift idea for kids of friends and relatives.

While this isn't a robotics kit, per se, it really builds the basic understanding of batteries, electronics, and motors that kids will need to move to the next level.

91lfaA93v0L._SL1500_

What robot kids do YOU recommend?



© 2014 Scott Hanselman. All rights reserved.
     

The Evolution of eInk

Sure, smartphones and tablets get all the press, and deservedly so. But if you place the original mainstream eInk device from 2007, the Amazon Kindle, side by side with today’s model, the evolution of eInk devices is just as striking.

Each of these devices has a 6 inch eInk screen. Beyond that they’re worlds apart.

8″ × 5.3″ × 0.8″

10.2 oz
6.4″ × 4.5″ × 0.3″

6.3 oz
6″ eInk display
167 PPI
4 level greyscale
6″ eInk display
300 PPI
16 level greyscale

backlight
256 MB 4 GB
400 Mhz CPU 1 GHz CPU
$399 $199
7 days battery life
USB
6 weeks battery life

WiFi / Cellular

They may seem awfully primitive compared to smartphones, but that’s part of their charm – they are the scooter to the motorcycle of the smartphone. Nowhere near as versatile, but as a form of basic transportation, radically simpler, radically cheaper, and more durable. There’s an object lesson here in stripping things away to get to the core.

eInk devices are also pleasant in a paradoxical way because they basically suck at everything that isn’t reading. That doesn’t sound like something you’d want, except when you notice you spend every fifth page switching back to Twitter or Facebook or Tinder or Snapchat or whatever. eInk devices let you tune out the world and truly immerse yourself in reading.

I believe in the broadest sense, bits > atoms. Sure, we’ll always read on whatever device we happen to hold in our hands that can display words and paragraphs. And the advent of retina class devices sure made reading a heck of a lot more pleasant on tablets and smartphones.

But this idea of ultra-cheap, pervasive eInk reading devices eventually replacing those ultra-cheap, pervasive paperbacks I used to devour as a kid has great appeal to me. I can’t let it go. Reading is Fundamental, man!

That’s why I’m in this weird place where I will buy, sight unseen, every new Kindle eInk device. I wasn’t quite crazy enough to buy the original Kindle (I mean, look at that thing) but I’ve owned every model since the third generation Kindle was introduced in 2010.

I’ve also been tracking the Kindle prices to see when they can get them down to $49 or lower. We’re not quite there yet – the basic Kindle eInk reader, which by the way is still pretty darn amazing compared to that original 2007 model pictured above – is currently on sale for $59.

But this is mostly about their new flagship eInk device, the Kindle Voyage. Instead of being cheap, it’s trying to be upscale. The absolute first thing you need to know is this is the first 300 PPI (aka “retina”) eInk reader from Amazon. If you’re familiar with the smartphone world before and after the iPhone 4, then you should already be lining up to own one of these.

When you experience 300 PPI in eInk, you really feel like you’re looking at a high quality printed page rather than an array of RGB pixels. Yeah, it’s still grayscale, but it is glorious. Here are some uncompressed screenshots I made from mine at native resolution.

Note that the real device is eInk, so there’s a natural paper-like fuzziness that makes it seem even more high resolution than these raw bitmaps would indicate.

I finally have enough resolution to pick a thinner font than fat, sassy old Caecilia.

The backlight was new to the original Paperwhite, and it definitely had some teething pains. The third time’s the charm; they’ve nailed the backlight aspect for improved overall contrast and night reading. The Voyage also adds an ambient light sensor so it automatically scales the backlight to anything from bright outdoors to a pitch-dark bedroom. It’s like automatic night time headlights on a car – one less manual setting I have to deal with before I sit down and get to my reading. It’s nice.

The Voyage also adds page turn buttons back into the mix, via pressure sensing zones on the left and right bezel. I’ll admit I had some difficulty adjusting to these buttons, to the point that I wasn’t sure I would, but I eventually did – and now I’m a convert. Not having to move your finger into the visible text on the page to advance, and being able to advance without moving your finger at all, just pushing it down slightly (which provides a little haptic buzz as a reward), does make for a more pleasant and efficient reading experience. But it is kind of subtle and it took me a fair number of page turns to get it down.

In my experience eInk devices are a bit more fragile than tablets and smartphones. So you’ll want a case for automatic on/off and basic “throw it in my bag however” paperback book level protection. Unfortunately, the official Kindle Voyage case is a disaster. Don’t buy it.

Previous Kindle cases were expensive, but they were actually very well designed. The Voyage case is expensive and just plain bad. Whoever came up with the idea of a weirdly foldable, floppy origami top opening case on a thing you expect to work like a typical side-opening book should be fired. I recommend something like this basic $14.99 case which works fine to trigger on/off and opens in the expected way.

It’s not all sweetness and light, though. The typography issues that have plagued the Kindle are still present in full force. It doesn’t personally bother me that much, but it is reasonable to expect more by now from a big company that ostensibly cares about reading. And has a giant budget with lots of smart people on its payroll.

This is what text
looks like on
a kindle.

— Justin Van Slembrou… (@jvanslem) February 6, 2014

If you’ve dabbled in the world of eInk, or you were just waiting for a best of breed device to jump in, the Kindle Voyage is easy to recommend. It’s probably peak mainstream eInk. Would recommend, would buy again, will probably buy all future eInk models because I have an addiction. A reading addiction. Reading is fundamental. Oh, hey, $2.99 Kindle editions of The Rise and Fall of the Third Reich? Yes, please.

(At the risk of coming across as a total Amazon shill, I’ll also mention that the new Amazon Family Sharing program is amazing and lets me and my wife finally share books made of bits in a sane way, the way we used to share regular books: by throwing them at each other in anger.)

[advertisement] What’s your next career move? Stack Overflow Careers has the best job listings from great companies, whether you’re looking for opportunities at a startup or Fortune 500. You can search our job listings or create a profile and let employers find you.

Sure, smartphones and tablets get all the press, and deservedly so. But if you place the original mainstream eInk device from 2007, the Amazon Kindle, side by side with today's model, the evolution of eInk devices is just as striking.

Each of these devices has a 6 inch eInk screen. Beyond that they're worlds apart.

8" × 5.3" × 0.8"
10.2 oz
6.4" × 4.5" × 0.3"
6.3 oz
6" eInk display
167 PPI
4 level greyscale
6" eInk display
300 PPI
16 level greyscale
backlight
256 MB 4 GB
400 Mhz CPU 1 GHz CPU
$399 $199
7 days battery life
USB
6 weeks battery life
WiFi / Cellular

They may seem awfully primitive compared to smartphones, but that's part of their charm – they are the scooter to the motorcycle of the smartphone. Nowhere near as versatile, but as a form of basic transportation, radically simpler, radically cheaper, and more durable. There's an object lesson here in stripping things away to get to the core.

eInk devices are also pleasant in a paradoxical way because they basically suck at everything that isn't reading. That doesn't sound like something you'd want, except when you notice you spend every fifth page switching back to Twitter or Facebook or Tinder or Snapchat or whatever. eInk devices let you tune out the world and truly immerse yourself in reading.

I believe in the broadest sense, bits > atoms. Sure, we'll always read on whatever device we happen to hold in our hands that can display words and paragraphs. And the advent of retina class devices sure made reading a heck of a lot more pleasant on tablets and smartphones.

But this idea of ultra-cheap, pervasive eInk reading devices eventually replacing those ultra-cheap, pervasive paperbacks I used to devour as a kid has great appeal to me. I can't let it go. Reading is Fundamental, man!

That's why I'm in this weird place where I will buy, sight unseen, every new Kindle eInk device. I wasn't quite crazy enough to buy the original Kindle (I mean, look at that thing) but I've owned every model since the third generation Kindle was introduced in 2010.

I've also been tracking the Kindle prices to see when they can get them down to $49 or lower. We're not quite there yet – the basic Kindle eInk reader, which by the way is still pretty darn amazing compared to that original 2007 model pictured above – is currently on sale for $59.

But this is mostly about their new flagship eInk device, the Kindle Voyage. Instead of being cheap, it's trying to be upscale. The absolute first thing you need to know is this is the first 300 PPI (aka "retina") eInk reader from Amazon. If you're familiar with the smartphone world before and after the iPhone 4, then you should already be lining up to own one of these.

When you experience 300 PPI in eInk, you really feel like you're looking at a high quality printed page rather than an array of RGB pixels. Yeah, it's still grayscale, but it is glorious. Here are some uncompressed screenshots I made from mine at native resolution.

Note that the real device is eInk, so there's a natural paper-like fuzziness that makes it seem even more high resolution than these raw bitmaps would indicate.

I finally have enough resolution to pick a thinner font than fat, sassy old Caecilia.

The backlight was new to the original Paperwhite, and it definitely had some teething pains. The third time's the charm; they've nailed the backlight aspect for improved overall contrast and night reading. The Voyage also adds an ambient light sensor so it automatically scales the backlight to anything from bright outdoors to a pitch-dark bedroom. It's like automatic night time headlights on a car – one less manual setting I have to deal with before I sit down and get to my reading. It's nice.

The Voyage also adds page turn buttons back into the mix, via pressure sensing zones on the left and right bezel. I'll admit I had some difficulty adjusting to these buttons, to the point that I wasn't sure I would, but I eventually did – and now I'm a convert. Not having to move your finger into the visible text on the page to advance, and being able to advance without moving your finger at all, just pushing it down slightly (which provides a little haptic buzz as a reward), does make for a more pleasant and efficient reading experience. But it is kind of subtle and it took me a fair number of page turns to get it down.

In my experience eInk devices are a bit more fragile than tablets and smartphones. So you'll want a case for automatic on/off and basic "throw it in my bag however" paperback book level protection. Unfortunately, the official Kindle Voyage case is a disaster. Don't buy it.

Previous Kindle cases were expensive, but they were actually very well designed. The Voyage case is expensive and just plain bad. Whoever came up with the idea of a weirdly foldable, floppy origami top opening case on a thing you expect to work like a typical side-opening book should be fired. I recommend something like this basic $14.99 case which works fine to trigger on/off and opens in the expected way.

It's not all sweetness and light, though. The typography issues that have plagued the Kindle are still present in full force. It doesn't personally bother me that much, but it is reasonable to expect more by now from a big company that ostensibly cares about reading. And has a giant budget with lots of smart people on its payroll.

If you've dabbled in the world of eInk, or you were just waiting for a best of breed device to jump in, the Kindle Voyage is easy to recommend. It's probably peak mainstream eInk. Would recommend, would buy again, will probably buy all future eInk models because I have an addiction. A reading addiction. Reading is fundamental. Oh, hey, $2.99 Kindle editions of The Rise and Fall of the Third Reich? Yes, please.

(At the risk of coming across as a total Amazon shill, I'll also mention that the new Amazon Family Sharing program is amazing and lets me and my wife finally share books made of bits in a sane way, the way we used to share regular books: by throwing them at each other in anger.)

[advertisement] What's your next career move? Stack Overflow Careers has the best job listings from great companies, whether you're looking for opportunities at a startup or Fortune 500. You can search our job listings or create a profile and let employers find you.

The real and complete story – Does Windows defragment your SSD?

There has been a LOT of confusion around Windows, SSDs (hard drives), and whether or not they are getting automatically defragmented by automatic maintenance tasks in Windows.

There’s a general rule of thumb or statement that “defragging an SSD is always a bad idea.” I think we can agree we’ve all heard this before. We’ve all been told that SSDs don’t last forever and when they die, they just poof and die. SSDs can only handle a finite number of writes before things start going bad. This is of course true of regular spinning rust hard drives, but the conventional wisdom around SSDs is to avoid writes that are perceived as unnecessary.

Does Windows really defrag your SSD?

I’ve seen statements around the web like this:

I just noticed that the defragsvc is hammering the internal disk on my machine.  To my understanding defrag provides no value add on an SSD and so is disabled by default when the installer determines the disk is SSD.  I was thinking it could be TRIM working, but I thought that was internal to the SSD and so the OS wouldn’t even see the IO.

One of the most popular blog posts on the topic of defrag and SSDs under Windows is by Vadim Sterkin. Vadim’s analysis has a lot going on. He can see that defrag is doing something, but it’s not clear why, how, or for how long. What’s the real story? Something is clearly running, but what is it doing and why?

I made some inquiries internally, got what I thought was a definitive answer and waded in with a comment. However, my comment, while declarative, was wrong.

Windows doesn’t defrag SSDs. Full stop. If it reports as an SSD it doesn’t get defraged, no matter what. This is just a no-op message. There’s no bug here, sorry. – Me in the Past

I dug deeper and talked to developers on the Windows storage team and this post is written in conjunction with them to answer the question, once and for all

“What’s the deal with SSDs, Windows and Defrag, and more importantly, is Windows doing the RIGHT THING?”

It turns out that the answer is more nuanced than just yes or no, as is common with technical questions.

The short answer is, yes, Windows does sometimes defragment SSDs, yes, it’s important to intelligently and appropriately defrag SSDs, and yes, Windows is smart about how it treats your SSD.

The long answer is this.

Actually Scott and Vadim are both wrong. Storage Optimizer will defrag an SSD once a month if volume snapshots are enabled. This is by design and necessary due to slow volsnap copy on write performance on fragmented SSD volumes. It’s also somewhat of a misconception that fragmentation is not a problem on SSDs. If an SSD gets too fragmented you can hit maximum file fragmentation (when the metadata can’t represent any more file fragments) which will result in errors when you try to write/extend a file. Furthermore, more file fragments means more metadata to process while reading/writing a file, which can lead to slower performance.

As far as Retrim is concerned, this command should run on the schedule specified in the dfrgui UI. Retrim is necessary because of the way TRIM is processed in the file systems. Due to the varying performance of hardware responding to TRIM, TRIM is processed asynchronously by the file system. When a file is deleted or space is otherwise freed, the file system queues the trim request to be processed. To limit the peek resource usage this queue may only grow to a maximum number of trim requests. If the queue is of max size, incoming TRIM requests may be dropped. This is okay because we will periodically come through and do a Retrim with Storage Optimizer. The Retrim is done at a granularity that should avoid hitting the maximum TRIM request queue size where TRIMs are dropped.

Wow, that’s awesome and dense. Let’s tease it apart a little.

When he says volume snapshots or “volsnap” he means the Volume Shadow Copy system in Windows. This is used and enabled by Windows System Restore when it takes a snapshot of your system and saves it so you can rollback to a previous system state. I used this just yesterday when I install a bad driver. A bit of advanced info here – Defrag will only run on your SSD if volsnap is turned on, and volsnap is turned on by System Restore as one needs the other. You could turn off System Restore if you want, but that turns off a pretty important safety net for Windows.

One developer added this comment, which I think is right on.

I think the major misconception is that most people have a very outdated model of diskfile layout, and how SSDs work.

First, yes, your SSD will get intelligently defragmented once a month. Fragmentation, while less of a performance problem on SSDs vs traditional hard drives is still a problem. SSDS *do* get fragmented.

It’s also worth pointing out that what we (old-timers) think about as “defrag.exe” as a UI is really “optimize your storage” now. It was defrag in the past and now it’s a larger disk health automated system.

Used under CC. Photo by Simon WüllhorstAdditionally, there is a maximum level of fragmentation that the file system can handle. Fragmentation has long been considered as primarily a performance issue with traditional hard drives. When a disk gets fragmented, a singular file can exist in pieces in different locations on a physical drive. That physical drive then needs to seek around collecting pieces of the file and that takes extra time.

This kind of fragmentation still happens on SSDs, even though their performance characteristics are very different. The file systems metadata keeps track of fragments and can only keep track of so many. Defragmentation in cases like this is not only useful, but absolutely needed.

SSDs also have the concept of TRIM. While TRIM (retrim) is a separate concept from fragmentation, it is still handled by the Windows Storage Optimizer subsystem and the schedule is managed by the same UI from the User’s perspective. TRIM is a way for SSDs to mark data blocks as being not in use. Writing to empty blocks on an SSD is faster that writing to blocks in use as those need to be erased before writing to them again. SSDs internally work very differently from traditional hard drives and don’t usually know what sectors are in use and what is free space. Deleting something means marking it as not in use. TRIM lets the operating system notify the SSD that a page is no longer in use and this hint gives the SSD more information which results in fewer writes, and theoretically longer operating life. 

In the old days, you would sometimes be told by power users to run this at the command line to see if TRIM was enabled for your SSD. A zero result indicates it is.

fsutil behavior query DisableDeleteNotify

However, this stuff is handled by Windows today in 2014, and you can trust that it’s “doing the right thing.” Windows 7, along with 8 and 8.1 come with appropriate and intelligent defaults and you don’t need to change them for optimal disk performance. This is also true with Server SKUs like Windows Server 2008R2 and later.

Conclusion

No, Windows is not foolishly or blindly running a defrag on your SSD every night, and no, Windows defrag isn’t shortening the life of your SSD unnecessarily. Modern SSDs don’t work the same way that we are used to with traditional hard drives.

Yes, your SSD’s file system sometimes needs a kind of defragmentation and that’s handled by Windows, monthly by default, when appropriate. The intent is to maximize performance and a long life. If you disable defragmentation completely, you are taking a risk that your filesystem metadata could reach maximum fragmentation and get you potentially in trouble.

Related Links

* photo by Simon Wüllhorst, used under CC BY 2.0.


© 2014 Scott Hanselman. All rights reserved.
     

There has been a LOT of confusion around Windows, SSDs (hard drives), and whether or not they are getting automatically defragmented by automatic maintenance tasks in Windows.

There's a general rule of thumb or statement that "defragging an SSD is always a bad idea." I think we can agree we've all heard this before. We've all been told that SSDs don't last forever and when they die, they just poof and die. SSDs can only handle a finite number of writes before things start going bad. This is of course true of regular spinning rust hard drives, but the conventional wisdom around SSDs is to avoid writes that are perceived as unnecessary.

Does Windows really defrag your SSD?

I've seen statements around the web like this:

I just noticed that the defragsvc is hammering the internal disk on my machine.  To my understanding defrag provides no value add on an SSD and so is disabled by default when the installer determines the disk is SSD.  I was thinking it could be TRIM working, but I thought that was internal to the SSD and so the OS wouldn’t even see the IO.

One of the most popular blog posts on the topic of defrag and SSDs under Windows is by Vadim Sterkin. Vadim's analysis has a lot going on. He can see that defrag is doing something, but it's not clear why, how, or for how long. What's the real story? Something is clearly running, but what is it doing and why?

I made some inquiries internally, got what I thought was a definitive answer and waded in with a comment. However, my comment, while declarative, was wrong.

Windows doesn’t defrag SSDs. Full stop. If it reports as an SSD it doesn’t get defraged, no matter what. This is just a no-op message. There’s no bug here, sorry. - Me in the Past

I dug deeper and talked to developers on the Windows storage team and this post is written in conjunction with them to answer the question, once and for all

"What's the deal with SSDs, Windows and Defrag, and more importantly, is Windows doing the RIGHT THING?"

It turns out that the answer is more nuanced than just yes or no, as is common with technical questions.

The short answer is, yes, Windows does sometimes defragment SSDs, yes, it's important to intelligently and appropriately defrag SSDs, and yes, Windows is smart about how it treats your SSD.

The long answer is this.

Actually Scott and Vadim are both wrong. Storage Optimizer will defrag an SSD once a month if volume snapshots are enabled. This is by design and necessary due to slow volsnap copy on write performance on fragmented SSD volumes. It’s also somewhat of a misconception that fragmentation is not a problem on SSDs. If an SSD gets too fragmented you can hit maximum file fragmentation (when the metadata can’t represent any more file fragments) which will result in errors when you try to write/extend a file. Furthermore, more file fragments means more metadata to process while reading/writing a file, which can lead to slower performance.

As far as Retrim is concerned, this command should run on the schedule specified in the dfrgui UI. Retrim is necessary because of the way TRIM is processed in the file systems. Due to the varying performance of hardware responding to TRIM, TRIM is processed asynchronously by the file system. When a file is deleted or space is otherwise freed, the file system queues the trim request to be processed. To limit the peek resource usage this queue may only grow to a maximum number of trim requests. If the queue is of max size, incoming TRIM requests may be dropped. This is okay because we will periodically come through and do a Retrim with Storage Optimizer. The Retrim is done at a granularity that should avoid hitting the maximum TRIM request queue size where TRIMs are dropped.

Wow, that's awesome and dense. Let's tease it apart a little.

When he says volume snapshots or "volsnap" he means the Volume Shadow Copy system in Windows. This is used and enabled by Windows System Restore when it takes a snapshot of your system and saves it so you can rollback to a previous system state. I used this just yesterday when I install a bad driver. A bit of advanced info here - Defrag will only run on your SSD if volsnap is turned on, and volsnap is turned on by System Restore as one needs the other. You could turn off System Restore if you want, but that turns off a pretty important safety net for Windows.

One developer added this comment, which I think is right on.

I think the major misconception is that most people have a very outdated model of diskfile layout, and how SSDs work.

First, yes, your SSD will get intelligently defragmented once a month. Fragmentation, while less of a performance problem on SSDs vs traditional hard drives is still a problem. SSDS *do* get fragmented.

It's also worth pointing out that what we (old-timers) think about as "defrag.exe" as a UI is really "optimize your storage" now. It was defrag in the past and now it's a larger disk health automated system.

Used under CC. Photo by Simon WüllhorstAdditionally, there is a maximum level of fragmentation that the file system can handle. Fragmentation has long been considered as primarily a performance issue with traditional hard drives. When a disk gets fragmented, a singular file can exist in pieces in different locations on a physical drive. That physical drive then needs to seek around collecting pieces of the file and that takes extra time.

This kind of fragmentation still happens on SSDs, even though their performance characteristics are very different. The file systems metadata keeps track of fragments and can only keep track of so many. Defragmentation in cases like this is not only useful, but absolutely needed.

SSDs also have the concept of TRIM. While TRIM (retrim) is a separate concept from fragmentation, it is still handled by the Windows Storage Optimizer subsystem and the schedule is managed by the same UI from the User's perspective. TRIM is a way for SSDs to mark data blocks as being not in use. Writing to empty blocks on an SSD is faster that writing to blocks in use as those need to be erased before writing to them again. SSDs internally work very differently from traditional hard drives and don't usually know what sectors are in use and what is free space. Deleting something means marking it as not in use. TRIM lets the operating system notify the SSD that a page is no longer in use and this hint gives the SSD more information which results in fewer writes, and theoretically longer operating life. 

In the old days, you would sometimes be told by power users to run this at the command line to see if TRIM was enabled for your SSD. A zero result indicates it is.

fsutil behavior query DisableDeleteNotify

However, this stuff is handled by Windows today in 2014, and you can trust that it's "doing the right thing." Windows 7, along with 8 and 8.1 come with appropriate and intelligent defaults and you don't need to change them for optimal disk performance. This is also true with Server SKUs like Windows Server 2008R2 and later.

Conclusion

No, Windows is not foolishly or blindly running a defrag on your SSD every night, and no, Windows defrag isn't shortening the life of your SSD unnecessarily. Modern SSDs don't work the same way that we are used to with traditional hard drives.

Yes, your SSD's file system sometimes needs a kind of defragmentation and that's handled by Windows, monthly by default, when appropriate. The intent is to maximize performance and a long life. If you disable defragmentation completely, you are taking a risk that your filesystem metadata could reach maximum fragmentation and get you potentially in trouble.

Related Links

* photo by Simon Wüllhorst, used under CC BY 2.0.



© 2014 Scott Hanselman. All rights reserved.
     

Getting ready for the future with the Microsoft .NET Portability Analyzer

.NET has been getting more and more portable. Not only is .NET Open Source going forward (read Announcing .NET 2015 – .NET as Open Source, .NET on Mac and Linux, and Visual Studio Community) but you of course know about Xamarin tools, as well as, I hope, the .NET Microframework, and much more.

You can run your .NET code all over, and there’s a tool to make this even easier. While you’ll rarely get 100% portable code with any platform, you can get into the magic 90-95% with smart refactoring, then keep the platform-specific shims pluggable.

The .NET Portability Analyzer is a free Visual Studio Add-in (or console app) that will give you a detailed report on how portable your code is. Then you can get a real sense of how far you can take your code, as well as how prepared you’ll be for the Core CLR and alternate platforms.

.NET Portability

Take a look at this report on AutoFac, for example. You can see that the main assembly is in fantastic shape across most platforms. Understandably the more platform-specific Configuration assembly fares worse, but still there’s a complete list of what methods are available on what platforms, and a clear way forward.

.NET Portability Report

You’ll get suggestions with a direction to head when you bump up against a missing or not-recommended API.

img2

You can analyze specific assemblies, or an entire project. Once installed, you’ll find the commands under the Analyze menu, and you can change options in the .NET Portability Analyzer options in the Tools | Options menu.

Even better, you can use this with the FREE Visual Studio Community that you can download at http://www.visualstudio.com/free.

Related Links


© 2014 Scott Hanselman. All rights reserved.
     

.NET has been getting more and more portable. Not only is .NET Open Source going forward (read Announcing .NET 2015 - .NET as Open Source, .NET on Mac and Linux, and Visual Studio Community) but you of course know about Xamarin tools, as well as, I hope, the .NET Microframework, and much more.

You can run your .NET code all over, and there's a tool to make this even easier. While you'll rarely get 100% portable code with any platform, you can get into the magic 90-95% with smart refactoring, then keep the platform-specific shims pluggable.

The .NET Portability Analyzer is a free Visual Studio Add-in (or console app) that will give you a detailed report on how portable your code is. Then you can get a real sense of how far you can take your code, as well as how prepared you'll be for the Core CLR and alternate platforms.

.NET Portability

Take a look at this report on AutoFac, for example. You can see that the main assembly is in fantastic shape across most platforms. Understandably the more platform-specific Configuration assembly fares worse, but still there's a complete list of what methods are available on what platforms, and a clear way forward.

.NET Portability Report

You'll get suggestions with a direction to head when you bump up against a missing or not-recommended API.

img2

You can analyze specific assemblies, or an entire project. Once installed, you'll find the commands under the Analyze menu, and you can change options in the .NET Portability Analyzer options in the Tools | Options menu.

Even better, you can use this with the FREE Visual Studio Community that you can download at http://www.visualstudio.com/free.

Related Links



© 2014 Scott Hanselman. All rights reserved.