SLI'd 2GB EVGA GTX680's... but max payne 3 shows 4096MB of VRAM?

[Beavermatic]

Just curious... was under the impression SLI only mirrored data between card VRAM, not combine them. So I should only have 2GB's of available VRAM on my SLI'd gtx680 setup.

However when I boot up Max Payne 3... in the graphics menu it shows the toll of all options you have enabled and how much VRAM it's consuming against the actual amount of VRAM in your machine. It's saying i have 4096MB of VRAM (4GB's), and that the game is using 4032MB's with everything maxed.

If i disabled SLI... it shows the correct amount, 2048MB of VRAM... which *should* also be the SLI amount, correct?

can anyone explain to me what's going on? Did nvidia implement some sort of VRAM combined update recently?

 

[Plimogz]

maybe Max Payne is multiplying by 2?

 

[Beavermatic]

Plimgoz...

But SLI doesn't stack VRAM in such a fashion... it uses one cards VRAM, and mirrors the DATA to the other card's VRAM... doesn't allocate the other cards VRAM as free space to use. Or at least it use to....


The only idea i have is that Max Payne 3 might be erroneously detecting the other cards VRAM as useable, though the strange thing is, the game is actually running like it is using 4GB's of VRAM... there's no way the game would be running as smooth as it does on just 2GB's with all the settings maxed out like i have them. So it's kinda strange

I'm not complaining, but I just don't seem to understand... it defies standard SLI logic.

 

[Jacky60]

Well I have same phenomenon here with each of my gpu's having 2gb (4gb per card) and GPUz showing I'm using max 3949mb. (arma 2 high draw distance) BUT having said that it runs like s**t at those settings.

 

[Makaveli]

Just curious... was under the impression SLI only mirrored data between card VRAM, not combine them. So I should only have 2GB's of available VRAM on my SLI'd gtx680 setup.

However when I boot up Max Payne 3... in the graphics menu it shows the toll of all options you have enabled and how much VRAM it's consuming against the actual amount of VRAM in your machine. It's saying i have 4096MB of VRAM (4GB's), and that the game is using 4032MB's with everything maxed.

If i disabled SLI... it shows the correct amount, 2048MB of VRAM... which *should* also be the SLI amount, correct?

can anyone explain to me what's going on? Did nvidia implement some sort of VRAM combined update recently?

I just think the game is looking at total vram on both and combining the totals.

That limitation of mirrored data is still there. Unless you see something directly from NV about it I wouldn't be too concerned about the information one game is showing you.

 

[PrincessFrosty]

Sounds like the method of detecting vRAM in the game isn't built to correctly account for multi-GPU configurations.

But the fact is that it's measuring the total used in the same way, so as a percentage of filled memory, or as some ratio/fraction it comes out correct anyway, if you want the actual values then just dive the given values by the number of GPUs you're running.

 

[Beavermatic]

So likely just a game anomaly, still actually 2GB's of VRAM...

However if I disable SLI, the game runs like crap at completely maxed settings (included MSAA and FXAA)... if i enable SLI, runs smooth as silk... and then some.

But that's likely not VRAM making the difference... that would be the performance addition from the SLI, correctley?


If thats the case, can anyone give me examples of what kind of issues you would see in a game from exceeding VRAM or hitting the limit of gpu VRAM?

 

[PrincessFrosty]

So likely just a game anomaly, still actually 2GB's of VRAM...

However if I disable SLI, the game runs like crap at completely maxed settings (included MSAA and FXAA)... if i enable SLI, runs smooth as silk... and then some.

But that's likely not VRAM making the difference... that would be the performance addition from the SLI, correctley?


If thats the case, can anyone give me examples of what kind of issues you would see in a game from exceeding VRAM or hitting the limit of gpu VRAM?

That's expected behaviour, when you add a 2nd GPU you're increasing the amount of processing power available in your system and you get better performance, you can either use that additional rendering power to run a game with better graphics settings, or you can leave the graphics options the same as what you'd use with a single GPU and enjoy higher frame rates.

Different game engines deal with vRAM limitations in different ways, usually what happens is that the game has to swap data in/out of vRAM back into your computers virtual memory (hard drive + system RAM) and because that process is slow it causes stuttering in the game.

FPS of any one scene is not really correlated or dependent on vRAM size, it's not like adding more vRAM gives you a higher FPS, it's something you either have enough of, or you don't.

When you have enough, performance is steady, when you don't have enough you'll incur stuttering during periods when data is swapped in/out of vRAM. During times when no data needs to be swapped the frame rate will be largely the same.

 

[Final8ty]

It reads the hardware and the fact is its 4GB of physical Vram regardless if it gets mirrored which is 2GB effective.

 

[Beavermatic]

thanks folks, think i understand whats going on now.

as usual... a great help!

 

[moonbogg]

Lots of people were all ass injured over the fact Max Payne needs over 2gb of Vram to max out at 1080p. People were bickering about how Nvidia, yet again, has crippled their cards with such low ammounts of Vram, much like the 570 suffered.
Honestly, for this generation, 2gb is quite low and makes sense for a mid range card which is what the 600 series cards are.

 

[cmdrdredd]

Plimgoz...

But SLI doesn't stack VRAM in such a fashion... it uses one cards VRAM, and mirrors the DATA to the other card's VRAM... doesn't allocate the other cards VRAM as free space to use. Or at least it use to....


The only idea i have is that Max Payne 3 might be erroneously detecting the other cards VRAM as useable, though the strange thing is, the game is actually running like it is using 4GB's of VRAM... there's no way the game would be running as smooth as it does on just 2GB's with all the settings maxed out like i have them. So it's kinda strange

I'm not complaining, but I just don't seem to understand... it defies standard SLI logic.

At what resolution? AT 1920x1200 I was pretty much pegged to 60fps in this game with everything maxed except AA.