SRT question

[red454]

After allocating space for SRT on an SSD, can you see how much of that space is being used?

For example, I have a 120 gig Corsair Force GT and I allocated the maximum amount of space for SRT. That left roughly 40 gig available for regular storage. I wonder if there is a way to see how much space the SRT is actually using.

 

[greenhawk]

it should, in theory, keep adding to the cache as files get accessed off the HDD. It would be a silly implementation if it stopped caching a file when space was not a issue (so some files might be cached but not used offten). That being said, I would think some space is not allocated for better performance (ie: working out what to stop caching when reading new data from the drive). For this "not currently being used" is proberly more of a "first to remove" in caching mode and free space when setup in maximumized mode (or what ever that mode is called were the SSD adds space to the HDD).

No point shrinking it if you want it to work at it's best.

 

[red454]

I see - I only use 7 or 8 programs regularly, so I would think that after the SRT figures out what to cache based on frequency of usage, then the space used on the SSD for SRT would remain fairly constant.

I don't plan to do any shrinking, but still, I wonder if there is a way to simply see how much you are actually using.

 

[Diogenes2]

Unless Intel offers some sort of utility, I think you are out of luck .. The cache space is transparent to the OS.

 

[GotNoRice]

I see - I only use 7 or 8 programs regularly, so I would think that after the SRT figures out what to cache based on frequency of usage, then the space used on the SSD for SRT would remain fairly constant.

That's not how SRT caches data. There is absolutely no "figuring out" anything nor does it make any kind of analyses of your usage patterns.

This is how SRT works:

You access a block of data for the first time from your mechanical Hard Drive, at which point it is also copied into cache.
The next time you access that same block, it will be accessed from cache instead.
As you access additional blocks of data from your mechanical Hard Drive, they will also be cached, and accessed from the cache upon subsequent requests for that block.
This process repeats until your cache is full at which point the oldest blocks in cache are pushed out of cache.

Note that I reference "blocks" because SRT works on the block/hardware level, not the file level or the program level. If you have a 3GB file that you only regularly access a few hundred megabytes of, only the blocks that contain those few hundred megabytes of data are likely be cached (as opposed to the whole file)

Until the cache actually fills up, it will continue to cache every single block that you access regardless of how frequently you access it. Only when the cache becomes full does anything start to be pushed out of cache, and at that point it will start with the oldest data in cache, not based on frequency of usage. Of course, anything you use on a regular basis is unlikely to become the oldest data in cache as it becomes the newest data in cache again every time you use that program.

 

[red454]

Ahhhh - so then if you had two systems, one with a 10 gig SSD and one with a 100 gig SSD and loaded the same software and used both systems in a similar manner (with SRT of course), then the 10 gig would be overwriting the "old" stuff far more often.

The advantage going to the larger SSD since it can maintain a larger cache library, and your applications would likely run more smoothly since all the cache data would be more likely to be "current". Am I correct?

I was a little confused since early on in my SRT understanding. I thought that the algorithms in the SRT monitored what you used most often and cached accordingly. Therefore, if you didn't run a lot of programs, you would use less space, and allocating a large amount would be wasteful.

 

[bryanW1995]

Unfortunately, it's not quite so clear-cut. You can only do either an 18.6gb cache, or a 64 gb cache. From what I've read, the 18.6gb cache is awesome but obviously has to "reload" more often. At least when you put your OS on the remaining data partition of the ssd, as you could/should with your setup, several users here have reported that their reads/writes actually can fall below standard spindle drive speeds. I don't know if that's been fixed or not, or even if it is typical for that matter b/c my 80gb drive forced me to use the 18.6gb cache anyway.

Here's a link to the discussion thread:

http://forums.anandtech.com/showthread.php?t=2172381