Warning! ATI users with 1 GB of RAM may encounter data corruption.

[StanTheMan]

If you have 1 Gigabyte of RAM and enable "Large System Cache" feature, on Windows XP, data corruption may occur.
I saw it mentioned by the latest ATI Catalyst driver when I set my friend's compie. luckily he's got only 512 meg of RAM.

here is the detail.
http://www.ati.com/support/infobase/4217.html

I haven't been able to reproduce the problem yet as my current system is loaded with ATI. It's loaded only with Geforce FX 5900 with 2.5Gig of RAM and "Large System Cache" enabled.
oh well, I'm an Nvidiot

 

[uOpt]

What I like best is that they don't say what the actual problem is.

You can only assume their driver is clobbering newly aquired page table entries with the AGP memory, but they don't say.

Bastards. And what happens to Linux users? Not that many use their mediocre drivers anyway, but it's a safe guess a similar problem might exist there. But with no driver source code noone could tell.

 

[Budman]

been running an ATI card & 1 gig of ram for over 1 1/2 years & I never had any problems.

 

[Tea Bag]

Originally posted by: Budman
been running an ATI card & 1 gig of ram for over 1 1/2 years & I never had any problems.

 

[BW86]

Originally posted by: Budman
been running an ATI card & 1 gig of ram for over 1 1/2 years & I never had any problems.

same here

 

[Gurck]

Originally posted by: Budman
been running an ATI card & 1 gig of ram for over 1 1/2 years & I never had any problems.

Only a few months here, but no problems either.

 

[Viper96720]

That's an old problem. Kind of known about it for awhile. Cause I got my ati card around Febuary of 03 and found out about that couple months later.

 

[Accord99]

Of course, non file servers shouldn't enable "Large System Cache" anyways since it hurts performance and XP has the setting disabled by default.

 

[YoYoBabyYo]

i've been running them for a few months, and recently my radeon 9800 pro started making really aweful (donkey like noise) with its fan. does anybody know what is wrong?

 

[StanTheMan]

Originally posted by: Accord99
Of course, non file servers shouldn't enable "Large System Cache" anyways since it hurts performance and XP has the setting disabled by default.

if you have more than a gig of ram at least (say 1.5 gig), then disable the large system cache will hurt performance. Anyway, what's a gig of ram for if not for cache? is there any programs, that utilise them?

for me i enable "large system cache" and "disable paging executive"

 

[StanTheMan]

Originally posted by: YoYoBabyYo
i've been running them for a few months, and recently my radeon 9800 pro started making really aweful (donkey like noise) with its fan. does anybody know what is wrong?

rpace it with zalman zm80d-hp. fanles dualpipe heatsink

 

[VirtualLarry]

This is a known, older problem. It's not 100% known whether the fault lies with XP, ATI, or a combination of both along with the system's chipset and AGP GART drivers. I have a feeling this may be why MS advocates using their chipset-agnostic "Universal AGP/GART" drivers, for hardware that is AGP spec 3.5-compatible.

A few interesting and semi-related datapoints - recent ATI Cat drivers newer than 4.9 have issues with Prime95 (at least on XP), it seems to simply "spin", and not use CPU time like it should. The cause of the problem is AFAIK unknown, but is suspected to do with VM or PTEs in some way.

There are also known issues with the game COD, with recent Cats.

Finally, there are issues with Punkbuster, on XP, with a large-memory AGP video card, mostly noticed on NF3/NF4 mobos with A64 CPUs, but some have noted the problem with other hardware too. The problem is intermittent "freezes" that can last for several seconds, and interrupt whatever gameplay is in progress. Interestingly enough, one of the workarounds is running W2K, for which the problem does not occur.

So there is indeed something funky going on in MS virtual-memory land, that may also be hardware/driver dependent.

 

[Accord99]

Originally posted by: StanTheMan

Originally posted by: Accord99
Of course, non file servers shouldn't enable "Large System Cache" anyways since it hurts performance and XP has the setting disabled by default.

if you have more than a gig of ram at least (say 1.5 gig), then disable the large system cache will hurt performance. Anyway, what's a gig of ram for if not for cache? is there any programs, that utilise them?

No, enabling Large System Cache means that Windows will allow the file cache to use up to 80% of memory, leaving only 20% for applications and the OS, even when you run many large applications. So even with 1.5GB of memory, any real use of the computer other than as a file server will see a dramatic reduction in performance.

 

[uOpt]

Originally posted by: Accord99
No, enabling Large System Cache means that Windows will allow the file cache to use up to 80% of memory, leaving only 20% for applications and the OS, even when you run many large applications. So even with 1.5GB of memory, any real use of the computer other than as a file server will see a dramatic reduction in performance.

Uh, certainly not because it only means it might take up 80% for the filesystem buffer cache, but it will not when memory is also requested by applications.

Every Unix system has that policy by default non-switchable, and they are certainly not hurting performance for applications.

 

[uOpt]

So is there any solid info on what exactly is happening there?

The ATI advisory doesn't even mention ATI cards or drivers, I have never seen an advisory so low on concrete information.

 

[Accord99]

Originally posted by: MartinCracauer

Originally posted by: Accord99
No, enabling Large System Cache means that Windows will allow the file cache to use up to 80% of memory, leaving only 20% for applications and the OS, even when you run many large applications. So even with 1.5GB of memory, any real use of the computer other than as a file server will see a dramatic reduction in performance.

Uh, certainly not because it only means it might take up 80% for the filesystem buffer cache, but it will not when memory is also requested by applications.

No, the file cache will always have priority. That's why the default setting for non-server products is the Large System Cache setting disabled.

 

[Ka0t1x]

9800 Pro and 1Gbyte xms4000, not a problem besides the weird dx9c sp2 slipstreamed glitch =)

 

[PingSpike]

Originally posted by: YoYoBabyYo
i've been running them for a few months, and recently my radeon 9800 pro started making really aweful (donkey like noise) with its fan. does anybody know what is wrong?

No, but the thought of a video card going "Hee-Ha! Hee-Ha!" did produce a chuckle out of me.

Seriously, it has to be a fan issue though.

 

[sharkeeper]

No, but the thought of a video card going "Hee-Ha! Hee-Ha!" did produce a chuckle out of me.

Seriously, it has to be a fan issue though.

One strange sounding fan indeed!

Cheers!

 

[jvarszegi]

Originally posted by: Accord99

Originally posted by: MartinCracauer

Originally posted by: Accord99
No, enabling Large System Cache means that Windows will allow the file cache to use up to 80% of memory, leaving only 20% for applications and the OS, even when you run many large applications. So even with 1.5GB of memory, any real use of the computer other than as a file server will see a dramatic reduction in performance.

Uh, certainly not because it only means it might take up 80% for the filesystem buffer cache, but it will not when memory is also requested by applications.

No, the file cache will always have priority. That's why the default setting for non-server products is the Large System Cache setting disabled.

No, you're absolutely wrong, and Martin is right. The effect of this setting is that the system dedicates more memory, when safe, to the system cache. Why have the setting at all, you ask? Because of the non-negligible expense of allocating and deallocating memory for the large system cache when lots of programs request it. This is not the same as paging.

 

[crimson117]

Originally posted by: Tea Bag

Originally posted by: Budman
been running an ATI card & 1 gig of ram for over 1 1/2 years & I never had any problems.

ditto, though I'm on a 6800gt now.

 

[Accord99]

Originally posted by: jvarszegi
No, you're absolutely wrong, and Martin is right. The effect of this setting is that the system dedicates more memory, when safe, to the system cache. Why have the setting at all, you ask? Because of the non-negligible expense of allocating and deallocating memory for the large system cache when lots of programs request it. This is not the same as paging.

No, withe Large System Cache enabled, the OS will use a maximum 80% of the system memory to the file cache and other system working sets. This is a soft maximum and the file cache and other system working sets can actually increase above 80%. Once memory limitations, the OS will trim back all the working sets back to their soft maximum, which is still 80% of memory.

Disabling Large System Cache means the soft maximum will be set to a much lower number, but in the presence of available memory, it can grow much higher.

 

[jvarszegi]

Originally posted by: Accord99

Originally posted by: jvarszegi
No, you're absolutely wrong, and Martin is right. The effect of this setting is that the system dedicates more memory, when safe, to the system cache. Why have the setting at all, you ask? Because of the non-negligible expense of allocating and deallocating memory for the large system cache when lots of programs request it. This is not the same as paging.

No, withe Large System Cache enabled, the OS will use a maximum 80% of the system memory to the file cache and other system working sets. This is a soft maximum and the file cache and other system working sets can actually increase above 80%. Once memory limitations, the OS will trim back all the working sets back to their soft maximum, which is still 80% of memory.

Disabling Large System Cache means the soft maximum will be set to a much lower number, but in the presence of available memory, it can grow much higher.

Nope. You can prove this to yourself by enabling large system cache on your laptop/desktop, then writing a simple program that allocates more than 20% of system memory. Your system will not be paging at this point. (I encourage anyone who doubts me to try this.)

 

[Brian48]

Originally posted by: BW86

Originally posted by: Budman
been running an ATI card & 1 gig of ram for over 1 1/2 years & I never had any problems.

same here

ditto

 

[BFG10K]

So there is indeed something funky going on in MS virtual-memory land, that may also be hardware/driver dependent.

I'd be far more likely to blame ATi rather than MS with regard to an issue like this. Having said that I never had such an issue on my ATi + 1 GB system.