[Scuddie]

Here's the deal.  I want to have decent I/O performance for disk access.  One option is an iRam controller, but that's a flawed and immature product.  Another option is to have a RamSan device, but I don't have several thousand dollars.  So I'm left with one final option, dedicating 512MB or so of system memory for read/write cache.  I have enough to spare, but I can't figure out how to tell WinXP to use system memory as cache for my main hard drive.  Can anyone point me to any reg settings for this sort of thing, or perhaps a program that will reserve a fixed amount of memory for cache?  I've googled it, and the only thing I can find is stuff regarding upcoming non-volatile solid state drives.

Anybody have any ideas?

[vyper]

I don't think you can.

Could switch your drives and interface to Ultra-640 SCSI - that's pretty damned fast anyway.

[CP5670]

I think you want to create something called a RAM disk, not increase the hard drive's cache manually (which is pointless anyway). Those used to be popular many years ago and there are several programs that let you do it. A google search throws up a bunch of them.

[Davros]

there are ddr based drives although not cheap

8000x faster at finding files than a 10,000 rpm SATA WD Raptor WD740ADFD
5500x faster at finding files than a 15,000 rpm SAS Seagate Savvio or Maxtor Atlas 15k II SAS drive
125x faster at serving files than a WD Raptor, certainly the fastest SATA drive on the market.
110x faster at serving files than any 15,000 rpm U320 SCSI or SAS drive.
700x faster at serving and receiving files than the latest Samsung laptop flash drives.

http://www.hyperossystems.co.uk/

[Scuddie]

Could switch your drives and interface to Ultra-640 SCSI - that's pretty damned fast anyway.

I wish that was cost effective, or even practical...

I think you want to create something called a RAM disk, not increase the hard drive's cache manually (which is pointless anyway). Those used to be popular many years ago and there are several programs that let you do it. A google search throws up a bunch of them.

I've already tried using RAMDisk, the performance increase was wonderful...  However, I am limited very much by the fact that I cant put anything of notable size on it.  Kinda eliminates the purpose.

Furthermore, why would you say it would be pointless to use system memory to create a buffer?  Most of the time I am playing games that require a lot of loading the same textures, models, sounds, etc repetitively, and a cache would significantly reduce reloading time, no?

there are ddr based drives although not cheap

As I said before, I dont want to use iRam type devices.  They are hard to find, expensive as hell, and not matured technology.  Not to mention the fact it needs ECC registered DDR memory, which is hard to find, expensive as hell, and volatile.

[jr2]

Hmm, well, to start with, you could get a hard disk with 32MB on-board cache... Most new drives come standard with 16MB, or 8MB if they are cheaper (or even 2!! ).  Then, for adjusting the Windows disk cache, you'd need a tweak util... I'm not sure which one has it, but there is Xen & XenTweak, TweakUI, PowerConfig, xTeq XSetup, jvUtils' jv16PowerTools, DeskSet, miTweak-XP, TweakAll3, etc... all are free, but scan for spyware with Spybot Search & Destory & Lavasoft Ad-Aware afterwards, just to be sure (most don't have that crap).  I did a Google Search for you, and you should check MajorGeeks as well, just watch the "license type", make sure it's freeware.

[CP5670]

I've already tried using RAMDisk, the performance increase was wonderful...  However, I am limited very much by the fact that I cant put anything of notable size on it.  Kinda eliminates the purpose.

Furthermore, why would you say it would be pointless to use system memory to create a buffer?  Most of the time I am playing games that require a lot of loading the same textures, models, sounds, etc repetitively, and a cache would significantly reduce reloading time, no?

The OS and game code should handle that automatically. This is the main purpose of the system memory, after all. If you're finding that your games are accessing the hard drive a lot ingame, you probably just need more memory. Some games also have options somewhere to pre-cache all data while loading a map/level, although most newer games do this by default already.

Hmm, well, to start with, you could get a hard disk with 32MB on-board cache...

I don't think such drives exist yet, and in any case a drive's onboard buffer is operated by its internal controller and is not for storing commonly used files at all. That is basically what the main memory is for.

[jr2]

Err... the buffer is used for prefetching, IIRC, and is highly effective.  And such drives do exist.  And, there are drives with even larger buffers than that.

EDIT:

http://en.wikipedia.org/wiki/Disk_buffer

[CP5670]

Your link contradicts what you're saying.

While data in the page cache is reused multiple times, the data in the disk buffer is rarely.

The buffer is used a lot during sequential reads, but the OS does not directly control what gets stored in there. It's not the same thing as system memory.

You may be right about the drives with large buffers though. Do you know of any specific models? I haven't seen any.

[jr2]

Hmph.  Coulda swore I saw some server hard disks for sale with 64MB cache... I don't see any.  Although I do see Hard Disk controllers with 64MB, maybe that's it.

Oh, and yes, I know my link contradicts me... notice the IIRC part of what I was saying.

[CP5670]

As far as I know, the buffers only go up to 16MB on commercially available units. Even the 16MB drives are more common in the desktop market. Most server drives still have 8MB, except for some of the newest SAS drives.

[jr2]

http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&DEPA=0&Description=32mb+cache&x=0&y=0


Oh, and @Scuddie:  To solve your problem, dropping 2x1GB sticks of dual channel RAM into your system should be good.

[CP5670]

Interesting, it looks like the latest 1TB drives do in fact have 32MB buffers, and the Hitachi one is already out. I wonder how they stack up to the Raptors. Need to read some reviews later today.

[ZmaN]

to be hoesnt i dont think the bigger cache makes any noticable difference...   maybe it loads certain things a little bit faster, but still its not worth trying to buy into it to get tahtextra speed.

I say go buy some more RAM.  That will speed the entire PC up, not jsut drive access...

[Excalibur]