Vista ReadyBoost experiences

[Zardoz]

If you are running Windows Vista and have not set up readyboost on it I urge you to do so. I had a spare 1GB SD card, so I gave it a try. When I activated the readyboost there was some HD activity for about a 1 min., then I started to mess around on the desktop.. I was impressed to what happen, I really did feel that the system seemed to be more snappy.

I was not really sure I would see much from it, as my system is a fairly speedy system (5.0 overall vista score) with 2 gigs of ram and some nice video. but even with just adding 1GB I did feel a speed change, So I started to look and find out more about readyboost.

Basically readyboost is a cache where information is stored. This information might be normally used off the hard drive or in system memory. The data can be access more quickly on this device as it's more random accessed data, hard drives have a hard time with random accessed data as they are much slower in doing that type of function and are better suited for large data reads.

Readyboost also relies on SuperFetch. SuperFetch is a intelligent memory manager. SuperFetch monitors your system for user activity, and will run programs like disk defragmenting and Windows Defender when you are not using your system. SuperFetch also monitors which applications you use the most and preloads these into your system memory so they'll be ready when you need them.

Just finding this out I went ahead and got a 4GB (the max you can use for readyboost) USB "ReadyBoost" drive. The readyboost drive is 200x speed and enhanced for Windows readyboost. I did not see much speed boost going from 1GB to 4GB, but my idea was that this would allow windows to store more cache and make more programs and info available for instant access. Microsoft claims that readyboost can improve system performance up to 30% this can be huge. I feel I got about 10 to 15% this is typically where you can feel a change with system performance.

Anyways, I hope this help you better understand readyboost and superfetch and how readyboost can improve performance on your Vista system.

Have fun,

 

[zacdl]

Just posted this over on another thread... might as well post it here too.
The bottom line is ReadyBoost isn't ever going to give you a big increase in performance.
It will improve a system with 512MB of RAM... but anything over 1GB won't see improvement until you hit the 4GB drive mark. Once you hit that mark, you could spend the same money on REAL RAM and get better performance out of it.

In conclusion... ReadyBoost is a waste of $$

 

[BinarySynapse]

those tests are flawed in two ways. One is that they didn't show any tests for 1GB+ with Readyboost, and the other is most them were CPU intensive tests or involved data that wouldn't normally be cached yet..

 

[zacdl]

those tests are flawed in two ways. One is that they didn't show any tests for 1GB+ with Readyboost

Boo hoo. They didn't test every single possible combination in the word

most them were CPU intensive tests

Almost half of them were HDD based performance tests.
Plus, you use a CPU to compute. You just do. In these tests, and in real life.
And it wasn't like they were testing it on different machines. The only thing that changed was the readyboost drive and RAM configurations. CPU was constant.

 

[SleeplessIncubus]

OP you said you had 2GB of system ram, right? Also the comp specs that are in your sig...was that the comp that was used?

Also, where did you buy your 4GB drive and how much did you pay?

 

[BinarySynapse]

Boo hoo. They didn't test every single possible combination in the word


Almost half of them were HDD based performance tests.
Plus, you use a CPU to compute. You just do. In these tests, and in real life.
And it wasn't like they were testing it on different machines. The only thing that changed was the readyboost drive and RAM configurations. CPU was constant.

My point for number one was that you claim there was no performance gain once you hit 1GB, but tests you displayed have no evidence to come to that conclusion. And for number two was that Readyboost enhances performance for disk I/O on random but frequently used data. All the tests your displayed either taxed the CPU and Disk I/O would have little impact on the end results or it involved data that wouldn't normally be cached (i.e Paged to the disk).

 

[Zardoz]

yeah I would agree, that some of the test do not show readyboost very well at all. but if you look at others they do show some boost, as my post tells, there was a snappy feel to it. as in when open stuff, not when you run something that just uses cpu like encoding MP3 or Video. I think the best show of readyboost is in the the readyboost with slower HDD and open close apps. you have almost 50% boost shown.

Something else to look at is that 4GB of USB flash memory is around 60 bucks and easy for ANYONE to install. to where 4GB of DDR or DDR2 memory is is roughly about 3 to 5 times more expensive and harder for some people to install.

bottom line is that readyboost is a cheep and easy way to get some extra performance out of any system.

 

[Zardoz]

OP you said you had 2GB of system ram, right? Also the comp specs that are in your sig...was that the comp that was used?

Also, where did you buy your 4GB drive and how much did you pay?

yes, I have 2GB of ram, the system in my sig is what I used. I got the drive from ebay cost was about 54 bucks shipped. the drive is an AData PD7 4GB 200X USB 2.0 Flash Pen Drive here are the specs;

Capacity : 4 GB
Interface : USB 2.0
Power Supply : DC 4.5V ~ 5.5V from USB port
Speed : 30MB/s (200x) read speed and 20MB/s (133x) write speed.
OS Supported : Works with Microsoft Windows Vista ReadyBoost to boost PC performance
Support Windows ME, 2000 and XP without device driver;
Support Driver for Windows 98/98 SE;
Driverless solution for Linux Kernel version 2.4 or later version;
Driverless for Mac OS 9.X or up;

Color : Silver Gray
Size : 66*19*10 (L*W*H)
Weight : 15g (+-0.5)
Package : Retail Package
Package Contents : USB Flash Disk *1
USB Extension Cable *1

 

[msny]

Cheaper at the egg $42.99

http://www.newegg.com/Product/Product.aspx?Item=N82E16820211098

 

[zacdl]

I think the best show of readyboost is in the the readyboost with slower HDD and open close apps. you have almost 50% boost shown.

Again- that is with the 4GB drive. You can spend about the same amount (maybe a little more) for true RAM and get a HUGE increase in performance. ReadyBoost offers very little. This goes into your next comment:

Something else to look at is that 4GB of USB flash memory is around 60 bucks and easy for ANYONE to install. to where 4GB of DDR or DDR2 memory is is roughly about 3 to 5 times more expensive and harder for some people to install.

You are comparing Apples to Oranges.
A 4GB flash drive is a TON slower than 4GB of real RAM.
The findings were... for the price you pay for a 4GB flash drive to get performance increase, you can buy less ram (like 1GB) and have a much better performance boost than ReadyBoost would ever give you. Make sense?
Its either pay for a 4GB and get a little better performance in a flash drive.
Or pay for 1GB RAM and get a TON better performance than that 4GB flash drive would ever give you.

bottom line is that readyboost is a cheep and easy way to get some extra performance out of any system.

Again... that isn't the bottom line.
"Out of any system" is the problem with your comment.
There are very few systems that actually benifit with ReadyBoost looking at both costs of upgrading to real RAM vs. buying flash drives, and comparing the differences in both methods.

 

[BinarySynapse]

Again- that is with the 4GB drive. You can spend about the same amount (maybe a little more) for true RAM and get a HUGE increase in performance. ReadyBoost offers very little. This goes into your next comment:

You are comparing Apples to Oranges.
A 4GB flash drive is a TON slower than 4GB of real RAM.
The findings were... for the price you pay for a 4GB flash drive to get performance increase, you can buy less ram (like 1GB) and have a much better performance boost than ReadyBoost would ever give you. Make sense?
Its either pay for a 4GB and get a little better performance in a flash drive.
Or pay for 1GB RAM and get a TON better performance than that 4GB flash drive would ever give you.


Again... that isn't the bottom line.
"Out of any system" is the problem with your comment.
There are very few systems that actually benifit with ReadyBoost looking at both costs of upgrading to real RAM vs. buying flash drives, and comparing the differences in both methods.

But if you already have the flash drive laying around then it costs nothing to implement. But that's neither her nor there. The biggest point about Readyboost is that anyone can do it for quick performance boost, including those who know nothing about upgrading their systems. To those of us woh can it's a non-issue more RAM=best performance, though.

 

[msny]

Lets make it simple
Readyboost flash RAM and storage with flash drive - cheaper price not as fast
RAM and no storage with real sticks - more expensive but faster

No endorsement either way

 

[zacdl]

But if you already have the flash drive laying around then it costs nothing to implement.

True.

anyone can do it for quick performance boost

And this is where I disagree. "Anyone" won't get a performance boost. Like I said- VERY few configurations would actually be able to utilize it to the point of actually noticing a difference.

Lets make it simple
Readyboost flash RAM and storage with flash drive - cheaper price not as fast
RAM and no storage with real sticks - more expensive but faster

That's just about got it covered

 

[Zardoz]

You are comparing Apples to Oranges.
A 4GB flash drive is a TON slower than 4GB of real RAM.
The findings were... for the price you pay for a 4GB flash drive to get performance increase, you can buy less ram (like 1GB) and have a much better performance boost than ReadyBoost would ever give you. Make sense?
Its either pay for a 4GB and get a little better performance in a flash drive.
Or pay for 1GB RAM and get a TON better performance than that 4GB flash drive would ever give you..

Yes and no, In a system that has a low amout of memory, I would agree that system memory would give you the best performance increase, but in a system that has alot of memory more ram would do you less, now with that would readyboost also do less for a system with tons of system memory.

More points on this, I have 2GB of system memory. I would go to say this is not a low amount, but it's not a crap ton as well. now currently with vista on the desktop and a few things going on my system us using about 46% of 2GB, I also have to take in account that readyboost is on, so I am not sure this is saving me any ram usage or not. but I have seen my memory usage up in the mid 50s. the fact is with MY system I did see a small boost. why would I see this boost if I still had avail. memory? what happens if I have 4GB of system memory do I still get a boost if I enable a readyboost disk?

Again... that isn't the bottom line.
"Out of any system" is the problem with your comment.
There are very few systems that actually benifit with ReadyBoost looking at both costs of upgrading to real RAM vs. buying flash drives, and comparing the differences in both methods

I find this flawed in a lot of ways. I think there comes a point where system memory will give you no more benifit you are assuming eveyone has low system memory. now my unknown is readyboost might be the same way in large system memory configs. but again with my 2GB I did see benifit even by installing a 1GB SD card I had laying around.

One more item, cost. I agree that system memory is the best way to get a performance increase on low memory configs. there is no question about that at all. but where do you stop adding memory? and have to look elsewhere to give you a performance increase or boost. remember this is a cache. it's not ment to replace system memery. it's more to help store frequent used info, so that it does not have to pull from other devices.

 

[Zardoz]

Lets make it simple
Readyboost flash RAM and storage with flash drive - cheaper price not as fast
RAM and no storage with real sticks - more expensive but faster

No endorsement either way

I agree with this...

but the only question will ready boost give you performance boost not matter the amout of avail. system memory.

 

[adrusch]

ReadyBoost might help people out more if they're running a laptop with limited expansion, or on a mobo where they're maxed out on RAM. I don't see much utility in using it on a 2GB or 4GB machine, though.

 

[sn3ak3rp1mp]

I have tried to use ReadyBoost, but don't have a flash drive fast enough for it. I'm not going to go out and spend $$$ on a flash drive when I already have 2GB of RAM and Vista runs just fine thanks.

However, I'm concerned about the slides thrown up in this post. The intent of ReadyBoost is to act as a prefetch cache and avoid expensive random reads from a "normal" HDD (read: typical system, one HDD, OS and everything else on it, not a Raptor, not an array, etc.) and I don't feel those slides are a fair test of what the software is designed to accomplish. See this for more information on ReadyBoost: http://blogs.msdn.com/tomarcher/archive/2006/06/02/615199.aspx

 

[BinarySynapse]

I have tried to use ReadyBoost, but don't have a flash drive fast enough for it. I'm not going to go out and spend $$$ on a flash drive when I already have 2GB of RAM and Vista runs just fine thanks.

However, I'm concerned about the slides thrown up in this post. The intent of ReadyBoost is to act as a prefetch cache and avoid expensive random reads from a "normal" HDD (read: typical system, one HDD, OS and everything else on it, not a Raptor, not an array, etc.) and I don't feel those slides are a fair test of what the software is designed to accomplish. See this for more information on ReadyBoost: http://blogs.msdn.com/tomarcher/archive/2006/06/02/615199.aspx

That's basically what I was trying to say.

 

[docmal]

Man this thread is hostile. If you don't want to use readyboost then don't.

But the fact is that if you use many business applications and switch large apps frequently then you will page to disk. Even with 2gigs of ram. I wish I had vista at work because I have a 1gig dual core machine and am a web developer. Every day I have outlook + visio + visual studio 2005 + SQL Manager Studio + Adobe Photoshop + Adobe Image Ready + Adobe Acrobat open all at the same time on two monitors. I switch apps like mad. I also page to disk frequently. If I had ready boost I would page to disk about 50% of the time. Sure if you have a decently quick disk and its defragged then it doesnt make a huge difference but most people don't have ideal scenarios at work.

I use readyboost at home and I agree it makes a difference. Not huge but I know it would make a bigger difference at work. I can't wait till we upgrade to vista 5 years from now

 

[clement]

Well if it doesn't decrease performance, and you have a drive sitting around that you don't use...why not use it?

I have a zillion of those flash drives laying around that I've gotten for free or almost free, none of which I use (don't ask why I got them in the first place ). Might as well put them to use I guess.

Now I don't think I would go out of my way to pay for a drive specifically for that purpose.

 

[Zinn]

One thing to keep in mind that system RAM is cleared when the power goes off. A flash drive maintains its data. Any cache data on the flash does not have to be accessed off the hard drive on bootup and paged into memory. In theory this means the PC will be more repsonsive on bootup.

RAM is nice but don't underestimate the value of solid-state persistant storage!

 

[bbz_Ghost]

One thing to keep in mind that system RAM is cleared when the power goes off. A flash drive maintains its data. Any cache data on the flash does not have to be accessed off the hard drive on bootup and paged into memory. In theory this means the PC will be more repsonsive on bootup.

RAM is nice but don't underestimate the value of solid-state persistant storage!

Nice idea, but that's not how it works with Vista. The ReadyBoost cache on the Flash-RAM device is wiped and repopulated after a reboot - it does not hold over from a previous session.

You can test this yourself by rebooting your machine (if you're using ReadyBoost, of course) and as soon as you get to a usable Desktop, run Task Manager, click the Resource Manager tab and open/expand the Disk activity section. Right near the top of the list - if not at the top - you'll see the ReadyBoost cache file getting a shitload of activity as Vista sorts through the previous session's SuperFetch cache set and data files (which are on the hard drive) and repopulates the ReadyBoost cache on the Flash-RAM device.

What you'll be looking for is the ratio of reading to writing: the writing data column will show significant activity compared to the read one meaning data from the hard drive is being sent to the cache file on the Flash-RAM device so it's mirrored once again and the two caches (SuperFetch and ReadyBoost) are in sync once again after a reboot.

This goes along with the theory and practical application that you can pull the ReadyBoost device anytime you want without even needing to do a "proper" Eject device operation. The data in the ReadyBoost cache is always on the hard drive first and foremost - the ReadyBoost cache just mirrors that but it is considered volatile meaning it can be wiped/destroyed/removed in the blink of an eye and it would cause no perceptible "damage" to the operating system or the SuperFetch subsystem.

Just wanted to clear that little bit up...

 

[Night Black]

Readyboost is already boosting the speed at which my computer runs. Pretty nice.

 

[Zardoz]

Nice idea, but that's not how it works with Vista. The ReadyBoost cache on the Flash-RAM device is wiped and repopulated after a reboot - it does not hold over from a previous session.

You can test this yourself by rebooting your machine (if you're using ReadyBoost, of course) and as soon as you get to a usable Desktop, run Task Manager, click the Resource Manager tab and open/expand the Disk activity section. Right near the top of the list - if not at the top - you'll see the ReadyBoost cache file getting a shitload of activity as Vista sorts through the previous session's SuperFetch cache set and data files (which are on the hard drive) and repopulates the ReadyBoost cache on the Flash-RAM device.

What you'll be looking for is the ratio of reading to writing: the writing data column will show significant activity compared to the read one meaning data from the hard drive is being sent to the cache file on the Flash-RAM device so it's mirrored once again and the two caches (SuperFetch and ReadyBoost) are in sync once again after a reboot.

This goes along with the theory and practical application that you can pull the ReadyBoost device anytime you want without even needing to do a "proper" Eject device operation. The data in the ReadyBoost cache is always on the hard drive first and foremost - the ReadyBoost cache just mirrors that but it is considered volatile meaning it can be wiped/destroyed/removed in the blink of an eye and it would cause no perceptible "damage" to the operating system or the SuperFetch subsystem.

Just wanted to clear that little bit up...

I do not think it wipes it (however I was not able to find if this is true). that would defeat some of what the readyboost cache is for, however I can see superfetch re-sinking readyboost, also superfetch updating what it has found changed in the boot process to help with performance. remember that superfetch is very dynamic it adjust to what your system is doing and tries to predict what files are needed so that it can make them more available quicker via readyboost and other means by the OS, there are other technologies that are around the corner that work much like readyboost, like readydrive and Intel's ITM (Intel turbo memory) onboard chipset readyboost flash. all of this uses superfetch in order to make files available quicker thru prediction.

 

[ThreeDee]

if readyboost improves performance or not on your system ..wouldn't it at least save some wear and tear on your hard drive? ...that would be worth it enough to me right there ...and with less hard drive activity that would equate a little less noise. For me and my 8+ fans going in my box , noise is not an issue tho ...I already got plenty of it

..if I'm wrong about readyboost decreasing hard drive activity ..then everything after that is moot in my post ..except of course the fact that my computer is noisey


[F]old|[H]ard

 

[zacdl]

I think you are [wrong about decreasing HDD activity].
As already said- the same stuff is stored on the hard disk. And because this data is already stored on your hard disk- you can imagine it isn't helping much at all.

It just equates to tiny little improvements in speed due to the fact you don't have to rely on your hard drive 100%.

At any rate- Vista is pretty much always doing SOMETHING I have found. It doesn't just sit around waiting for the next time you move the mouse- it puts itself to use!

 

[Unknown-One]

ReadyBoost does make my laptop feel faster (it has 1GB of DDR2) while running in a normal Windows environment, but it can actually hurt performance when running games. I know I get far more stuttering in Oblivion while ready boost is enabled, and as soon as the flash drive is unplugged my frame rates even out again.

How do you explain this? By the simple fact that USB has one hell of a CPU overhead. I've had systems slow down to a crawl when transferring large files (~300MB) over to flash drives, to the point where you just have to leave the system alone until your transfer has finished. There's no way to get around USB overhead, so ReadyBoost will slow things down when something CPU intensive (games) start taking over.

Now, firewire has no such CPU overhead, so if you were to use ReadyBoost on a firewire based flash drive (like the FireFlash) you should be able to get around this limitation.

 

[Zinn]

Now, firewire has no such CPU overhead, so if you were to use ReadyBoost on a firewire based flash drive (like the FireFlash) you should be able to get around this limitation.

Good info! I did not realize USB was that CPU intensive.

Now are you sure firewire flash drives are Readyboost supported?

 

[bbz_Ghost]

Theoretically they are - the documentation and specifications for ReadyBoost support merely require a Flash-RAM based device sooo...

I know there are a few Firewire Flash-RAM devices (one of the most popular ones is the Micromat one used for Apple Macintosh repair and troubleshooting work, called Protege), but as for regular PC use I've never seen one in stores or in use by anyone I know.

Again, theoretically it should. If Vista recognizes it as a removable storage device and you see an option for ReadyBoost duties, well, there ya go.

 

[s10010001]

I don't know, but I have 4gb of RAM in vista (shows 4108mb system memory) and a 2gb ready boost drive. It dont seem to affect my apps or games at all but it dose seem to make just browsing around my computer faster. So I leave the 2gb flash plunged in. Whats it hurting?

Your not a geek unless you have spare unused 2gb thumb drives laying around. Might as well make em work for you.


+you really think MS is that dumb, im sure they extensively tested it and they know exactly what it dose.

 

[Zardoz]

I think you are [wrong about decreasing HDD activity].
As already said- the same stuff is stored on the hard disk. And because this data is already stored on your hard disk- you can imagine it isn't helping much at all.

It just equates to tiny little improvements in speed due to the fact you don't have to rely on your hard drive 100%.

At any rate- Vista is pretty much always doing SOMETHING I have found. It doesn't just sit around waiting for the next time you move the mouse- it puts itself to use!

As stated hard drives don't do random reads as well as memory type devices, this includes flash. this is one area that readyboost addresses. all of theses factors give you a better experience.

 

[Zardoz]

ReadyBoost does make my laptop feel faster (it has 1GB of DDR2) while running in a normal Windows environment, but it can actually hurt performance when running games. I know I get far more stuttering in Oblivion while ready boost is enabled, and as soon as the flash drive is unplugged my frame rates even out again.

How do you explain this? By the simple fact that USB has one hell of a CPU overhead. I've had systems slow down to a crawl when transferring large files (~300MB) over to flash drives, to the point where you just have to leave the system alone until your transfer has finished. There's no way to get around USB overhead, so ReadyBoost will slow things down when something CPU intensive (games) start taking over.

Now, firewire has no such CPU overhead, so if you were to use ReadyBoost on a firewire based flash drive (like the FireFlash) you should be able to get around this limitation.

I don't think this is a big issue, the type of files on a readyboost drive tend to be small and access are quick bursts. plus readyboost does more reading, then wrights.

 

[Zardoz]

I don't know, but I have 4gb of RAM in vista (shows 4108mb system memory) and a 2gb ready boost drive. It dont seem to affect my apps or games at all but it dose seem to make just browsing around my computer faster. So I leave the 2gb flash plunged in. Whats it hurting?

this is what readyboost is for...

 

[jpochedl]

I've got a laptop with 2GB of ram (2x1GB sticks)... Upgrading the laptop to 4GB would be quite expensive (like $1200 last time I checked)... I generally have a dozen or so apps open (Word, Excel, Outlook, Photoshop Elements, IE, my RSS reader, and whatever else I happen to be jumping around in)... Things seemed to get a little pokey when switching between apps...

However, I do have a SD card slot that sits unused when I'm not copying pictures off my camera's card... I grabbed a 2GB SD card for $40... The card sits flush with the side of the computer when inserted, so there's no ungainly "dongle" sticking out the side...

After installing the SD card and enabling readyboost, performance when switching apps (or opening another app) definately feels smoother now... For example, the 3 to 4 second lag that used to accompany clicking to open a new Word doc is gone. When you're updating screen shots in a dozen different Word docs, it makes a difference...

Obviously it's a subjective eperience, and updating to 4 gigs of RAM would be great.... However, there's a big difference between $1200 and $40... For me, it was $40 well spent. If someone else wants to argue that readyboost worthless, well, there's nobody forcing them to use it.... I'll continue to enjoy the minor improvement in my day to day work experience.

 

[bbz_Ghost]

Obviously it's a subjective eperience, and updating to 4 gigs of RAM would be great.... However, there's a big difference between $1200 and $40... For me, it was $40 well spent. If someone else wants to argue that readyboost worthless, well, there's nobody forcing them to use it.... I'll continue to enjoy the minor improvement in my day to day work experience.

QFT, very well put and PRECISELY what ReadyBoost is supposed be do and be used for.

 

[aznx]

I have 2gb of ram and with a 4gb Sandisk Micro Cruzer with ReadyBoost on...my system gets choppy, but if I take out the usb drive, it returns to normal. Also with the usb drive plugged in, system uses about 20% cpu constantly. I have an Athlon64 3000+ @ 2.5ghz, is my hd/memory too fast or something, or am I doing this wrong? I've also removed the U3 software off the Sandisk but it didn't seem to make a difference..

Any ideas?

 

[Zardoz]

I have 2gb of ram and with a 4gb Sandisk Micro Cruzer with ReadyBoost on...my system gets choppy, but if I take out the usb drive, it returns to normal. Also with the usb drive plugged in, system uses about 20% cpu constantly. I have an Athlon64 3000+ @ 2.5ghz, is my hd/memory too fast or something, or am I doing this wrong? I've also removed the U3 software off the Sandisk but it didn't seem to make a difference..

Any ideas?

This is not normal, I would say you have a problem with USB controller drivers or the hardware might be having problem, might be the USB controller or the memory stick. it is not with your hd/memory being too fast I would try a different USB memory stick.

 

[aznx]

This is not normal, I would say you have a problem with USB controller drivers or the hardware might be having problem, might be the USB controller or the memory stick. it is not with your hd/memory being too fast I would try a different USB memory stick.

Hmm, I'm currently running a DFI nForce4 Ultra-D, the USB ports seem OK at transferring other stuff such as through my iPod or my microSD reader. Should I get a RMA on the USB drive? Would that be the problem? The drivers seem OK for my board..

 

[Zardoz]

Hmm, I'm currently running a DFI nForce4 Ultra-D, the USB ports seem OK at transferring other stuff such as through my iPod or my microSD reader. Should I get a RMA on the USB drive? Would that be the problem? The drivers seem OK for my board..

Well if everything else you have works ok, and this is the only device that seems to have this issue, I would suspect this as being the source of the problem. however it might be an incompatibility with this brand device and USB controller.

Anyways, I would think an RMA is in order as the USB device is not working as specified.