GTX 970 VRAM allocation bug

Maybe because gpu have 4GB vRAM, but using usually around 3500 MB only...

I like this card, but all what I need is explain why or how vram management works if 980 using all memory without problem but 970 no.

 

Just because there's 4GB of VRAM available, doesn't mean it all has to be utilized.

 

My question is about using in games where 980 allocating ALL in 1080p, but 970 no in same settings, same game, same place... And sometimes 970 don´t allocate 4GB nor in 4K...

 

If you had x2 970s like I do you don't end up with 8GB VRAM. You still have 4GB VRAM as the VRAM on the second card is mirrored to the first card. So each both pools of memory act as one.

The same goes for any SLI or Crossfire setup, the memory does not add on.

Same goes for if you had Tri SLI Quad SLI and the same for Tri-Fire and QuadFire in Crossfire.

 

Maybe Manuel G (or a veteran/current hi tech engineer :grad may give a solid answer. Though I don't think is a "bug" or something similar, neither on purpose by Nvd (for a future boost with a driver dedicated to performance for 970s, :3eyes

 

anyone ever thought that Nvidia has coded into the drivers for the 970's to only ever use 3.5GB VRAM for games and they reserve the extra 512MB for DSR or Shader Cache maybe.

Might depend on the game type, I have seen 3.9GB usage on my 970's thats not using DSR either.

 

I've seen too more than 3.5 however only when using strong AA or/and downsampling(dsr,ssaa,downsampling...bottom line these are very similar on their result yet with different methods plus filter for dsr).

Edit: also don't forget that each game's engine run specific calculations about how much Vram will be used on what and if am not mistaken each engine comes with limitations (with some hundreds of MB reserved..). Please correct me if I am wrong here..

 

Ran a few more tests with Far Cry 4.

On Max Settings at 1440p:

SLI: 3550MB was pretty much the highest it would go.
GPU1 (non SLI): 3800MB was around where it capped out.
GPU2 (non SLI): 3800MB was around where it capped out.

 

Hm,does anyone know why dxdiag x64 show different Vram...?
(AB shows about ~370MB in use when dxdiag was making it's measurement,in case that a smart@ss writes that x64 dxdiag counts dynamically Vram etc :wanker



Edit: a pic that shows SoM scans correctly max vram(don't know if it's scanning methof is dynamic or just reads specs of the gpu's stuff)

http://i.imgur.com/JRTIjVQ.jpg

 

Well, both 32 and 64 show 3627mb for me. What does a GTX980 get?

@OP are you using Windows 7?

 

Looks like Win 8 shows the system memory and not GPU memory,
How much system memory do you have?

 

Me shows total: 10.231 MB vRam, physic memory is 12 GB DDR3 RAM (1600), 4096 MB dedicated vRam, 6135 MB vRam is shared with Ram (that is by me unnecessary - ddr3 as vram? bad slow joke...)

 

Faulty known dxdiag readings...I'd like to suggest enough of this because we kinda "spam" OP thread guys.

 

I shoot up to anywhere from 3.5gb to 3.8gb in shadow of mordor. Other games like FC4 I've seen well over 3.5gb too depending on the scene. The 970's will definitely have enough power to push memory usage just like the 980 does. Heck, cards like the G1 are perform the same as a stock 980 so the 970 cards are more than capable.

 

The issue here is 970 pushing 3500mb in the same scene were 980 pushes 4000mb. Whether the card requires it or not is out of the question. Why this is happening is the question. And once you go above 3500mb you get stutters, as if vram and ram swapping going on in the last 512mb.

I tried skyrim, at first I thought the crap engine is at fault, but reading this thread made sense. Whenever skyrim goes above 3.5gb, there is a lot of hitching.

 

Yes - question is "why?", because 980 haven´t problem in same scene with allocation all.. (and no fps drops compared to 970 with all allocation) But I think - only nVidia knows why and they say nothing without some press news etc...

 

prolly best leaving the word 'bug' outta the next thread title if you're looking for nvidia response.
as far as we know it's working as intended.

 

... GTX 970 (1367/7012)



... GTX 980 memory 8000 MHz

Memory bug? No, maybe it´s "feature"...

And- see attached files and differences! :nerd:

 

It looks like GTX970 is not 256Bit card...
That why card dont like use more than 3500Mb Vram
Its similar to GTX660TI.

 

nVidia in a fog

Yes, it is possible, maybe 224 bit or less... Or who knows what all is bad... Hiding nVidia facts in a fog? :3eyes: