Wrong vram usage

[jebediah]

Hi guys.
Don't know if this has been up before, but i could not find any answer.

I'm running with two 7970 and both card has 3GB vram.
But when i'm monitoring vram usage with GPU-Z and other software like Aida64 it tells me that i'm using around 4GB usage.

Don't know if i've missed anything or just missunderstand the whole thing, but perhaps someone can shed some light on the issue.

 

[Athlon2K15]

Whats the issue?

 

[jebediah]

Whats the issue?

How i'm able to use 3856 MB on a 3 GB card

 

[mroofie]

How i'm able to use 3856 MB on a 3 GB card

miracles

 

[xvi]

..erm, spilling over to system ram? Not entirely sure.

 

[jebediah]

Thanks for some fast reply.
There's not much more to explain. The screenshoot is taken while gaming.
I've tried MSI Afterburner some time ago, and it said the same thing, also Aida64

But if i take a look in Aida64 detailed overlook it says that both my cards only has 3GB.

Think i've had this "problem" since day one.
Well, it's not a big deal and i can live with it. But it would be nice to see the actual vram usage.

 

[jebediah]

Yes i am, but correct me if i'm wrong.
It does not matter if you are using 1 or 10 cards. The sum of vram only counts from the first card?

 

[W1zzard]

It does not matter if you are using 1 or 10 cards. The sum of vram only counts from the first card?

That's how I understand the reported value as well.

I have no explanation for your reading. What game are you running?

 

[jebediah]

That's how I understand the reported value as well.

I have no explanation for your reading. What game are you running?

Everything that comes over 2GB
But mostly BF4 "64bit", World of Tanks, Sid Meiers Civilization Beyond Earth, Borderlands The Pre-Sequel, Far Cry 4

 

[vega22]

we have found where nvidia lost theirs?

too soon?

has to be reading some kind of dynamic figure showing a combo or vram and system ram?

 

[jebediah]

we have found where nvidia lost theirs?

too soon?

has to be reading some kind of dynamic figure showing a combo or vram and system ram?

Hahaha.. Thanks, that made my day

EDIT: I've tried to google any solution, and it seems strange that no one else has encounter the same problem.

 

[xvi]

I was wondering if it's the sum of both cards as well, but it seems kind of odd for it to report like that. Maybe try taking one card out and see what it reports then? ¯\_(ツ)_/¯

 

[jboydgolfer]

AMD is giving Extra RAM now?? and Nvidia cant give what they sell . Just kidding, sorry couldn't resist.

Seriously though, I would try running a single card setup, and see what the VRam readout is then...it might be a crossfire thing.

 

[jebediah]

I was wondering if it's the sum of both cards as well, but it seems kind of odd for it to report like that. Maybe try taking one card out and see what it reports then? ¯\_(ツ)_/¯

I would if i did not run with a custom loop. It's just to much work to tear down all the tubes

EDIT: Hmm, maybe if i just disable Crossfire. I will give it a try

EDIT 2: That was strange. With CF disable it looks like the card only can use 1900 MB.

 

[xvi]

I would if i did not run with a custom loop. It's just to much work to tear down all the tubes

EDIT: Hmm, maybe if i just disable Crossfire. I will give it a try

EDIT 2: That was strange. With CF disable it looks like the card only can use 1900 MB.

Oh yeah, would just find a way to disable the card if you've got it in a loop, which it sounds like you've done. I can't imagine why it would add memory usage together for both cards in CF since that's not quite how it works. Seems very odd. I suppose that's how it wants to do it though. I guess just treat it like you have 6GB of memory.

 

[m4gicfour]

@W1zzard: does GPU-Z read that value from DirectX?

I seem to remember reading somewhere that DirectX counts both (or all) cards together as used memory despite the fact that the data is simply duplicated on each card, with the justification being that the memory is still in use; it's just not a single pool with unique data on each card. I.E. reporting 4GB (2 cards x 2GB) out of 6GB (2 cards x 3GB) usage

If I had half a clue where I read that, I'd link source but I haven't the foggiest.


EDIT - I seemed to remember Afterburner doing the same thing when I had two 58X0 cards, so I just checked, and indeed, in BF4 x64 MSI AB's onscreen display reports:

Crossfire disabled, it reports usage of GPU MEM1 as 32MB and GPU MEM2 as a little over two gigs,

Crossfire enabled, it reports usage of GPU MEM1 as 4194304MB and GPU MEM2 as 5604MB

This is with my two 290Xes at 5760x1080, so regardless of where the value is coming from be it driver or DX, it's just summing memory usage.