Solved Why is HDD speed related to ReadyBoost?

[M4dn3ss]

From the Windows help file:
"If your computer has a hard disk that uses solid-state drive (SSD) technology, you may not see an option to speed up your computer with ReadyBoost when you plug in a USB flash drive or flash memory card. This is because some SSD drives are so fast they're unlikely to benefit from ReadyBoost."

What does ReadyBoost have to do with HDD speed at all? Doesn't it just use a flash drive as fake RAM?

 

[ICIT2LOL]

Basically not much at all if you look at this it will explain. A lot of people think it is actually virtual RAM but only a sort of caching I never found it of any use whatsoever.
ReadyBoost - Wikipedia, the free encyclopedia

 

[M4dn3ss]

Call me blind but I can't find anything on the Wikipedia page that says it's related to the HDD at all except that the flash drive cache is "faster than the hard drive being cached". This begs the question, why is readyboost disabled by default whenever you have an SSD?

 

[UsernameIssues]

I could be wrong - but doesn't MS put the SuperFetch info into the ReadyBoost RAM space? I don't think that the RAM was intended as a generic addition to the existing RAM.

The best thing would be to put the SuperFetch info into regular RAM.
(But you might not have enough RAM - hence the ReadyBoost offer.)

The second best thing would be to put the SuperFetch info into the swap file.
(If that swap file is on an SSD...
...then that will be faster than putting the SF info into ReadyBoost RAM),

Why would MS want to offer you an option to slow your computer down?

edit: that info is wrong - I think.

Again - I could have this all wrong. It has been a while since I looked into it.

 

[M4dn3ss]

What exactly do you mean by "SuperFetch info"? Wouldn't that just be the information Windows has about what programs to 'fetch' into memory, and thus be relatively small and probably not even in memory to begin with?
If you mean the page file, well what if the page file is disabled?

 

[ICIT2LOL]

What exactly do you mean by "SuperFetch info"? Wouldn't that just be the information Windows has about what programs to 'fetch' into memory, and thus be relatively small and probably not even in memory to begin with?
If you mean the page file, well what if the page file is disabled?

Windows Vista I/O technologies - Wikipedia, the free encyclopedia scroll down to superfetch.

 

[M4dn3ss]

As I said, SuperFetch info wouldn't need to be stored in RAM since it's just a bit of data about what programs are most used and whatnot

 

[UsernameIssues]

As I said, SuperFetch info wouldn't need to be stored in RAM since it's just a bit of data about what programs are most used and whatnot

I don't think that your understanding of SuperFetch is complete.
(I know that my understanding of SuperFetch is limited


Perhaps this document can help us:
Windows PC Accelerators

Specifically:

If a device supports ReadyBoost, it provides a dedicated area where SuperFetch can securely store a copy of performance-crucial data. SuperFetch can retrieve data from a cached copy on nonvolatile flash storage much faster than from disk. SuperFetch typically compresses the data that it writes to the cache at a 2:1 ratio; sometimes it can compress up to a 3:1 ratio. By default, SuperFetch encrypts using 128-bit Advanced Encryption Standard (AES) to ensure security of the data.

Some (most?) SuperFetch info loads/stays in RAM.
edit: maybe not

 

[ICIT2LOL]

As I said, SuperFetch info wouldn't need to be stored in RAM since it's just a bit of data about what programs are most used and whatnot

Yes I think User described it better than me then - I am just curious as to why you need to know are you fixing an old machine or is it yours? Because if it is your machine and it is running perfectly ok I have lost the plot somewhere here.

Now if it is your machine and it is running out of RAM just throw in another 4GB as I see it is DDR2 not that it is no good in fact my tester runs perfectly well on 4GB.
If the machine spitting the dummy playing games maybe the RAM is on the way out in which case I would push a memtest through it.

 

[M4dn3ss]

Sorry I misunderstood you, you made it sound like you meant SuperFetch info as in "the data that Windows stores about what should be prefetched" rather than "the stuff that is actually being prefetched".
Anyway I still don't see what the HDD has to do with it, since prefetch data is either in RAM or it's on a ReadyBoost drive, never on a hard drive. Unless it's in the page file.

 

[Pauly]

but the data it is fetching is on the HDD and if the hdd/ssd is faster you wouldnt want to slow it down by introducing a usb port

 

[M4dn3ss]

Fair enough, but so does that mean that ReadyBoost is only for SuperFetched data?

 

[ICIT2LOL]

Hmm M4d well from my limited understanding of all that mate it was down to something to do with temporary storing in a page file or whatever.

I don't know about anyone else but anytime I used it I could not tell any difference in speed or any form of performance enhancement. I came across it when I first went over from an XP onto a Vista machine.

I suppose it must have done something but for me even with my limited usage wasn't worth the cost of a USB stick. I don't think as Pauly says today it isn't going to make any difference because the SSD is that much faster than even the fastest spinners. I just wouldn't be bothered with it mate just forget about it enjoy the SSD - I do

If you want something real handy run through this
http://www.sevenforums.com/tutorials/11728-optimize-windows-7-a.html and be happy

 

[UsernameIssues]

I've marked thru some of my earlier posts... I'll have to think about it more.

 

[pbcopter]

See this.

Understand ReadyBoost and whether it will Speed Up your System

1st paragraph.

"Windows 7 supports Windows ReadyBoost. This feature uses external USB flash drives as a hard disk cache to improve disk read performance. Supported external storage types include USB thumb drives, SD cards, and CF cards. Since ReadyBoost will not provide a performance gain when the primary disk is an SSD, Windows 7 disables ReadyBoost when reading from an SSD drive."

 

[x BlueRobot]

ReadyBoost is used to improve caching speeds, it is a false popular belief that it provides more RAM or acts as RAM. It primarily uses data in the SuperFetch cache at first, however, later on once all the apportiate ReadyBoost services have been loaded, the Ecache.sys reads all disk I/O to the connected hard-drives, and then begins writing any data from these disk I/Os into a cache file stored on the USB flash drive.

 

[kado897]

I think the point is that Windows would be reading that data from a slower HDD instead of the flash drive.

 

[x BlueRobot]

I think the point is that Windows would be reading that data from a slower HDD instead of the flash drive.

 

[LMiller7]

A flash drive cannot be used to "fake" RAM. The operating and performance characteristics of a flash drive are totally wrong for that to be possible. What ReadyBoost does do is act as a disk cache. A basic concept in any kind of caching is that the media acting as the cache must be faster than the media being cached. Flash drives usually have slower transfer rate than a conventional drive but they do have a much better seek time. Since seek time is usually more important then transfer rate in real world situations a flash drive does make an effective cache. But RAM is a much more efficient disk cache than any flash drive could hope to be. But effective disk caching requires a lot of RAM so on systems where it is limited there just isn't enough.

Since flash drives usually have inferior performance characteristics they cannot act as a cache for an SSD. In that case ReadyBoost would actually impair performance.

ReadyBoost is most effective on systems with slow hard drives (greater benefits from caching), a fast flash drive (a faster cache), and limited RAM (not enough for efficient caching).

 

[whs]

I understand Ready Boost as follows:

1. RB is only useful if you have small RAM (e.g. 1GB or less) - with larger RAM you get quasi no paging.

2. If the system requires more RAM than you actually have, it starts 'paging'. That means that parts of the RAM content is written out to disk to make room for the 'new' process. It is Superfetch that controls that process.

3. If you have setup a stick for RB, the pages are written to the stick and to the disk - so they are written twice for integrity reasons to guard against someone pulling the stick out.

4. If the pages that were written out have to be retrieved, Superfetch will first look whether it can do so from the stick. Reason is because a good stick has a much faster access time (appr. 1ms) versus a disk (appr. 15ms). So that speeds up the process.

If you take a stick which is much slower than 1ms access time, you are not really gaining anything. Sticks that are really slow, are anyhow rejected by the system for RB usage.

5. For systems that have 2GB or more, RB is counterproductive and may slow your system down - because of the RB overhead. Those systems have little or no paging activity.

6. In case of a SSD for an OS disk, RB really makes no sense at all because the SDD access time is 0.1ms on average. That is 10 times faster than the best stick.