GTX 970 VRAM allocation bug

Wolfenstein TNO using 4006 MB on my 970 all settings maxed 1440p via DSR

 

You have any 3d mark 11 or 13 scores pre maxwell? If you do run it again with the latest drivers.

 

In Far Cry 4 @ 1440p
No AA: 3320MB Max Vram, locked at 60 fps
2x MSAA: 3405MB Max Vram, locked at 60fps
4x MSAA: 3500MB Max Vram, 45-60fps
8x MSAA, starts around 3700-3800MB @ 4-5fps, stabilizes at 3500MB @ 30-40fps.

 

And Memory Burner utilizes 3979MB as well. See a pattern here? Wolf TNO and Memory Burner are OpenGL applications, and so far we are discussing DirectX11 games. Skyrim is a DirectX9 game.

 

You can reliably fill 970 VRAM past 3.5GB by starting some old undemanding game which uses 300-500 MB of VRAM.
AND THEN start your test game.

To make sure that the "old game" when minimized does not use any GPU resources (other than VRAM), use AB and check for GPU usage.

 

Unfortunately I don't, just some games

But are your GPU's pegged at 99% in that scenario? 8xMSAA on FC4 isn't an easy task. Would be nice to reproduce the issue in VRAM intensive situations that don't involve the processing power as much.

 

I also managed to fill 3970Mb using Memory Burner. And I did manage to make Skyrim and Shadow of Mordor to use the 4GB of vram on my GTX 970.

So there's evidence that the card can use it's 4GB. Maybe it's the games that are having some problem recognizing, or adresssing, the full 4GBG pool.

 

The issue is that it can't fill 4 GB without some ungodly performance drop at about 3.5GB (hence it mainly stays under 3.5GB)

Not that 4GB can't be filled

 

Yeah, those are at 99% :-/

 

If you throw huge amounts of AA and resolution performance will drop regardless of there being a problem with memory addressing in the GTX 970.

 

The thread started off as not being able to utilize 4GB, now it turned into the performance issues. It'll be best if someone can fill up the VRAM between 3500-3900 without the having the GPU's pegged at 99%.

 

Try what Noisiv suggested, run a game minimised that uses a lot of VRAM and be in another game that won't stress the GPU's, let us know what happens with your performance. Memory usage between 3500-3900 would be ideal so VRAM bottleneck won't be an issue.

 

Window 1: Torchlight 2. Nothing else running, 627MB vram.
Window 2: Far Cry 4 (same settings that net 3.5GB as listed before). Both games running, 3.5GB.

Tabbing between both games shows 3.5GB of vram in use.

 

I have a few 11 and 13 benches from a year ago, maybe I`ll try running them now if there is any interest using 347.09

 

Did you try Kombustor's GPU Memory Burner ?

 

maybe not the best idea after all; god knows what happens with VRAM allocation in between tabs. NEXT

 

Yup. Works with no issue up to 39xx. Doing some Skyrim tests now as that uses more vram than gpu power.

 

Found this:



http://www.guru3d.com/index.php?ct=articles&action=file&id=12830

Thats an ungodly and unexplainable 50% difference between 970/980.
And that setting is definitely using 4+ GB, watch Titan pull ahead of 780 Ti, although it has less of everything ecept RAM

So, it could be per game issue, because in other 4k games difference between 970/980 is largely as expected.

 

Got it working with Skyrim with DSR@5120x2880. I wonder if there is some limit based on the GPUs % usage?



Edit:

And Far Cry is using more than 3.5GB @ DSR 4k:
DSR@4k



Just had two friends try their 980s at the same settings people here are getting capped at 3.5GB and both got 4GB in FC4.

 

No it's not the ~10 FPS difference is mostly clock related @ 1500 MHz you gonna reach that most probably though @ higher energy (lower efficiency) cost as you compensate the lower amounts of SMMs with this to some degree.
Of course you wont compensate the geometry performance lose entirely even with OCing to the Magic 1500 Mhz

The best tests you can find are the direct FCAT compares by Digitalfoundry no other reviewer can beat those

http://www.eurogamer.net/articles/digitalfoundry-2014-nvidia-geforce-gtx-970-review

All the results where pre Omega Driver though.

2K



4K


Here is the OCed result from the very well known MSI 4G Gaming

1080p



Though the problem with the video releases is of course you always see only 1 specific result in motion but according to the frametimes there should be no visible different problems

Driver wise though the newest Nvidia Driver has a hickup in terms of a SLI flag that interfers with Single GPU Latency in the CryEngine, so when someone should do a new Fcat compare also in terms of the allocation matter that should be taken into account as well.