• Some users have recently had their accounts hijacked. It seems that the now defunct EVGA forums might have compromised your password there and seems many are using the same PW here. We would suggest you UPDATE YOUR PASSWORD and TURN ON 2FA for your account here to further secure it. None of the compromised accounts had 2FA turned on.
    Once you have enabled 2FA, your account will be updated soon to show a badge, letting other members know that you use 2FA to protect your account. This should be beneficial for everyone that uses FSFT.

Dual chip cards memory

U

unreal89

Limp Gawd
Joined
Jul 21, 2010
Messages
270
In a recent discovery I learned that SLI and CF setups only use the amount of memory as one card (because the memory is mirrored). I was wondering if the dual gpu cards use all of their memory? i.e. the 590 uses 3GB vs 1.5GB?
 
Memory is mirrored between GPUs when in SLI/Cfx. If each GPU on a dual-card only has 1.5GB of VRAM then that is all you get when paired. Same as when you have physically separate GPUs.
 
So my GTX 690 says it has 4GB of memory but I really only have 2GB to run my multimonitor setup?
 
unreal89 said:
So, you can run a single chip at full memory capacity?
Click to expand...

Nope amigo.

The simple explanation is that memory is mirrored. What is actually happening is that each GPU has it's own dedicated VRAM pool attached to the separate GPUs, and in SLI those memory pools are filled with identical data (essentially halving the total available memory pool). One GPU can't use the VRAM attached to the other GPU within my knowledge.
 
I guess it makes sense, cause then the memory bandwidth would have to be doubled to keep the performance the same. I just think it's misinformed advertising.
 
Not just the memory bandwidth, the bandwidth between the cards need to be vastly improved. There's just no physical way to make the bandwidth between cards match the bandwidth between the GPU and vRAM. The physical distance alone makes this impossible.
 
if you do NOT have SLI or Xfire enabled, all of the memory on a single card is used.

So if your card has 4G of ram on it - it will use all 4G on it if not in SLI/XFire

Once you turn on SLI / XFire , you have the memory mirrored, so if you have 2 cards and each card has 4G of ram, then you only have 4G of ram to use, not 8G.
 
You must log in or register to reply here.
Back
Top