2nd GTX 680: Will VRAM be an issue?

[notty22]

VRAM usage is not the same across different GPUs. Also its not easy to measure correct VRAM usage either. Plus a GPU with more memory might simply allocate more, even if not used.

The only real way is essentially to see when FPS drops off the chart. Thats when the memory bottleneck hits.

How I understand it. The drivers are tweaked to get the best performance. Forcing a situation through mods and seeing more than 2gb usage on a 3gb radeon or 6gb titan does not mean a 2gb card can't run smooth.

 

[omeds]

Did you watch your VRAM usage? Was it hitting 2GB?

Depending on the scene yes, but hitting 2GB doesnt automatically translate into issues either.

The only game I have had issues was Skyrim with 4096x4096 texture pack, I had to use the 2048x2048 texture pack instead, and this is with 4xSGSSAA. But this is also because Skyrim was not designed to run with such high textures in the first place, meaning streaming/swapping isnt happening as it should with such textures. In the Crysis2 benchmark for example its also pegged at 2GB the whole time, but the game is designed to stream smoothly with the textures it has, and performance is fine without a hitch.

 

[Elfear]

The answer is yes but in practice I've had no issues using 4xAA+trSSAA in any game at 1440p with 2GB. 8xMSAA presents an issue in a few games though.

That's good to know. I wish there were a slick program out there that could measure actual vram usage rather than allocation. It would make questions like the OP's much easier to answer.

 

[omeds]

Yes allocation and the minimum required are two different things, and its very difficult to measure as you can only ever read what is allocated via afterburner etc.

How I understand it. The drivers are tweaked to get the best performance. Forcing a situation through mods and seeing more than 2gb usage on a 3gb radeon or 6gb titan does not mean a 2gb card can't run smooth.

Yes exactly. Just because a 3GB card allocates 2.5GB worth of data, doesnt mean a 2GB card cant run the game perfectly well.

 

[2is]

For my resolution of 1680x1050 you need 1GB of VRAM. (Dual GTX 460 1GB)

For 1920x1080 you need 2GB of VRAM. (Dual GTX 670 2GB)

For 1920x1200 you need 3GB of VRAM (Dual GTX 7970 3GB)

And for 2560x1600 you need 4GB of VRAM or more. (Dual GeForce Titan 6GB)

I don't think I want to know where you pulled that from...

For example. Why would an 11% increase in pixels (1080 vs 1200) require a 50% increase in VRAM? It wouldn't.

 

[BrightCandle]

The thing is some games load information they don't directly need into the GPU because they expect to need it at some point soon. In theory it improves performance, but it also distorts the picture of the required VRAM. Its used a lot with ansitropic filtering where all the detail levels are loaded but then some of them are dropped when it turns out you aren't even remotely close enough to use them and the VRAM would be better used elsewhere.

So allocation count while interesting and indicative doesn't prove there is a problem, it proves the maximum utilisation given the games free reign to do what it likes. The problems show up in the performance if there is a problem and not in the afterburner captured VRAM allocation count.

A great example of this is Tomb Raider. Tomb raider actually runs better on a 680 GTX, but according to the reviews that game utilises 2.5GB of VRAM on the Radeon but only 2.0GB on the GeForce. Yet the 680 performs better. If the actual allocation was over 2.0 you would still see that, overallocation shows up in afterburner as well so what is actually happening is the game is just not loading certain cached assets, but it has no practical impact on the performance.

BF3 is another example of a game that in surround over allocates but then doesn't need them to run smoothly.

There are many examples of this but you really have to go quite extreme to actually see performance degrade due to the VRAM limitation. When you get to that point your frame rate is normally so low anyway it really doesn't matter. The grand majority of games actually sit around 1GB of VRAM usage at these sorts of resolutions.

So many references to reviews showing that it makes no difference and it really doesn't. I was a happy surround gamer for years and had no issues on lower amounts of VRAM, I only recently swapped to 120Hz in preference after a lot of recent games showed not to support the mode very well. But it still ran the games well, there wasn't an issue. You run out of performance before you run out of VRAM.

 

[UaVaj]

http://www.hardocp.com/article/2013/01/14/asus_geforce_gtx_670_directcu_ii_4gb_sli_review/6

You are wrong. I have already proven that. Stop posting misinformation. 2gb cards actually provide a better experience in bf3 at 5760x1200.

Now please post a source of your claim as I have for the fourth time or stop posting lies.

should learn to stop digging yourself into a hole. seriously.

need me to dissect your link for you?

670sli 2gb - 5760x1080 FXAA 16AF + 670sli 4gb - 5760x1080 FXAA 16AF
vs
680sli 4gb - 5760x1080 4xMSAA 16AF (2.6gb vram called for)

-----

video say a million words. :whiste:

http://www.youtube.com/watch?v=mNgJJT92s64

 

[Eureka]

should learn to stop digging yourself into a hole. seriously.

need me to dissect your link for you?

670sli 2gb - 5760x1080 FXAA 16AF + 670sli 4gb - 5760x1080 FXAA 16AF
vs
680sli 4gb - 5760x1080 4xMSAA 16AF (2.6gb vram called for)

-----

video say a million words. :whiste:

http://www.youtube.com/watch?v=mNgJJT92s64

Usage != requirement.

 

[UaVaj]

as for the ultimate how much vram question.

better to have it and not need it,
then to need it and not have it.

each to its own.

 

[omeds]

Couldn't agree more, but thats not of much use if you already have 2GB cards.

 

[digitaldurandal]

VRAM usage is not the same across different GPUs. Also its not easy to measure correct VRAM usage either. Plus a GPU with more memory might simply allocate more, even if not used.

The only real way is essentially to see when FPS drops off the chart. Thats when the memory bottleneck hits.

Correct, if the driver sees extra VRAM it will cache everything it can, which is not necessary. As I was saying, without having hitching in game play your VRAM is fine.

One issue with battlefield 3 is that it doesn't store anything in RAM only VRAM and swapfile, so you will notice caching issues easier.

 

[digitaldurandal]

http://www.youtube.com/watch?v=mNgJJT92s64[/URL]

Thank you. You have just proven my point against you. I think you are too dense to realize it.

Once again we are talking about a one step AA drop between the two at best, in a single game.

Have you actually read my posts? I am not sure that English is your first language. Perhaps I should get someone to translate for you?

Sorry to stoop to your level but your snarky posts and refusal to read anything and your attitude for four pages wore me down.

 

[digitaldurandal]

No problem.




With one 7970 it actually ran pretty well at max settings. With SLI/CF it would be no problem at all.

Here is the FPS graph at 1600p 8xMSAA, 8xAAA, and FXAA (basically the last two data point from the graph above). The OC setting was 1325/1600.

I agree with you that most games will be just fine with 2GB of vram and, for those few that aren't, turning down a few settings will correct the texture thrashing. The OP asked whether he would be limited by 2GB and with dual/triple/quad cards than the answer is yes. You have the GPU power to run a game at max settings but insufficient vram. If you're spending $$$ on video cards, why would you want to turn settings down because of a vram limit?

Anyway, I'm not trying to make a mountain out of a molehill but knowing what your limits are can help make an informed decision. If the OP doesn't play any of the games mentioned and upgrades often, 2GB won't be a problem at all.

Wow, I am impressed by those figures tbh.

He asked if he would be severely limited. I do think there are situations where he is limited by one tick on the AA slider. Some games may be worse than that but most will be fine.

It is unfortunate that the benchmark was with a 7970. If it had been a 570 4gb I could run the same thing on my computer and get a closer comparison to how it will actually affect features.

 

[UaVaj]

Thank you. You have just proven my point against you. I think you are too dense to realize it.

Once again we are talking about a one step AA drop between the two at best, in a single game.

Have you actually read my posts? I am not sure that English is your first language. Perhaps I should get someone to translate for you?

Sorry to stoop to your level but your snarky posts and refusal to read anything and your attitude for four pages wore me down.