GTX 970 VRAM allocation bug

This is actually very interesting - this would suggest that driver / bios doesnt allow you to actually use more than 3gb vram on the 970, and what you instead use, is the pagefile (aka shared memory), when you go above 3gb vram used, hence the slow Down at high vram usage.

If this is not a bug, then nvidia has some explaining to do.

 

Absolutley they would have some explaining to do, when I read the guys post with the furmark test about pagefile alarm bells went off regarding the guys that play Advanced Warfare could not get the game to run properly with gtx970 or for sure many could not until they put at least 12gb pagefile on system for when having 8gb system ram.

I mean who would of thought that having a 4gb card with 8gb system ram would need a 12gb pagefile to play that game, seriously eh. I have always run my system with bare min pagefile enough for a dump if **** happens but with that game it would just crash out.

Something is most odd here, and as for "shared memory" what is this the 1990's again, get with it nvidia.

 

i've been using 'system managed' page file since watch dogs.

 

And how did you get/calculated this 39% difference if GPUs are only 20.7% different physically?

GTX980 and GTX970

CUDA cores 2048 > 1664 (20.6897% difference)

TMUs 126 > 104 (20.6897% difference)

SM units 16 > 13 (20.6897% difference)

ROPs 64 = 64

In worst case fillrate difference was 33.3~% according to numbers posted here and 28% according to nvidia

 

It's more efficient to look @ frametime fluctuations and how they behave then to look @ FPS results.

But it could explain the Dunia 2 behavior in Watch_Dogs as well as FarCry 4 and Nvidias heavy fixing on it trying to get Frametimes more stable and finaly they pretty much achieved it with the newest WHQL.

Though this improvement on Watch_Dogs and Dunia Streaming results can nowehre be found in the Changelogs but can be reproduced easily in terms of Frametime improvements.

The changes significantly improved especially High (Watch_Dogs) and Medium (FarCry 4) Texture streaming results in terms of Frametime fluctuations (High Speed Streaming).

No Patch from Ubisoft was able to gain these improvements until the new 347.09 Beta Driver.


Here you can see measurements of this improvement and a Video showing it Subjectively.

http://www.forum-3dcenter.org/vbulletin/showthread.php?p=10461732#post10461732


That massive Motion improvement came with 347.09 Beta for GM204 in this case GTX 970

 

My reply was to the 3DMark Vantage Color Fill comparision right above my post.

Basically 1562 GTX970 - 27.56GPixel/s , 1550 GTX980 - 38GPixel.

If the 970 has 64ROPs, then it should be closer in margin to the GTX980 but its not. This is because in a regular workload only 52 ROPs of the GTX970 are used. Read the techreport page a few posts back.

 

Sir, I hope not to offend, but your post did nothing for the topic at hand.

Back OT -

I am watching this issue with great interest, I was about to hit the button on a new system ($5K AU all up) but this has stopped me dead in my tracks.

Hope its clarified and rectified ASAP.

 

- ignore post, just me being stupid before coffee in the morning.

 

Found out about this possible issue on Reddit via the GeForce forums, which in turn lead me here. I've basically built my first PC in 10 years (been using a MacBook Pro for the last 6 for some gaming in Bootcamp) and bought a Gigabyte Gaming G1 GTX 970 for it. I'm not sure what to make of this issue and my results.

I ran MSI Kombuster and the Memory Burn Test @ 1680x1050:

1GB benchmark 137FPS
2GB benchmark 111 FPS
3GB benchmark 37FPS

It managed to allocate 3923MB of the 4096MB, but the frame rates were way off compared to 1GB and 2GB. Is that normal? Given the drop from 1GB to 2GB I would have expected 90FPS.

Also after the Reddit thread I ran SpaceEngine for 40 minutes and was able to push 3700MB - 3800MB, with a max of 3846MB. There doesn't appear to have been any performance degradation. (I still have the 715k CSV file)

Go to i.imgur.com/yU6cmeo.png to see. (Seems I need to post some posts first, oops)

The only really recent releases I have that might push VRAM I guess are Star Citizen, Elite Dangerous and Metal Gear Solid Ground Zero but I haven't actively checked those yet.

 

I just tried the same thing and got similar results on Memury burner.

Using the 720p preset, without MSAA.

1GB preset - 1447MB vram usage - 185 fps
2GB preset - 2087MB vram usage - 153 fps
3GB preset - 3884MB vram usage - 59 fps

That is one huge drop.

 

Agreed Horus-Anhur, I wasn't sure if that drop off was to be expected or not. I'm very curious what the drop off is like for a GTX 980.

 

I would like to see if the 980 has a similar drop, before running to conclusions.

 

Yeah, I'm curious too.

 

I can confirm heavy stuttering in Skyrim when more than 3.5GB is used.
I also can confirm that Kombustor memory burner fails allocating more than 3.5GB VRAM if pagefile is disabled.
Without pagefile, AC: Unity makes the system crash when I enable 4xMSAA in 1440p...
I feel deceived and want my money back!

 

try asking in 980 owners thread, or even making a new '980 owner request' thread.

 

Hi there guys I'm new in your forum it is unfortunate to meet under these circumstances but anyway It's nice to meet you .As you can imagine I have the same issue as you do.So I ran some tests with games and benchmarks and I can defnately tell you that something odd is going on I am not even sure how to interpret those results so I am going to share it with you and hope someone could come up with something.
First, just like you I can't get it to utilize all of it's memory.It doesn't matter waht settings I choose even at 4k res the usage stays around 3500-3600MB.Currently I am playing CoD AW and when I max it out everything turned on or to it's maximum value at 4k the used memory is 3300-400MB the strange thing is that when I run the with the setting I pl,ay with wich are the same only the supersampling is set to x2 instead of x8 and the res is 1080p then the usage is 3500-550MB wich is realy strange.The case is the same with other games .
Second,I checked out to see waht DXDIAG will show and strangly when I run the 32 bit diag it shows 4095 MB vRAM,but when I run the 64 bit it shows only 3580 MB of vRAM wich I am not sure that is how it's suppose to be.
And third wich I find the most disturbing is that I've tried the MSI's mem burn test as someone sugested on some of the previos posts.The thing is that the half of tha times I try to run it my PC freezes when I get it running the framerates are 1/3 less than the 2Gb test.At the 2G test I get 165fps while at the 3G test I get only 60-65 fpsbut that is not the worst.I decided to check the task manager while running the tests and I saw somethng very wierd .When I run the 2Gb mem test the system memory usage is around 1.9-2.2Gb but when I run the 3Gb mem test the system memory usage is 6.8-7.1Gb so I'm thinking that maybe when 4G is needed it loads them from the system memory instead of the integrated vRAM tha could explain the severe decrease in performance becase the system memory is much more slower.
As I said I don't know how to interpret such a results and do not want to run into any conclusions but I realy hope it is software related otherwise....
Anyway I am sure that here are people who are more competent than me and can give some opinon.It would be good to know where exactly the issue is and f there is any solution.Thanks in advance,best regards.

 

From which memory manufacturer you have, my MSI have ram from samsung.

When I have a pagefile.sys off, MSI Kombustor test crash due to lack of memory, allocates only 2,7GB VRAM.

 

Samsung,and I will try turning off pagefile.sys and see what will happen.I'll let you know when I am done.

 

Any 980GTX owners in the house to test this?
If the 980GTX passes this without the performance drop, we're in deep ****.

 

@FrAnTiC
For me dxdiag shows 4095 and dxdiag /64bit shows 2600

EDIT: Hynix memory