VRAM Usage - 6970 (2 GB) vs. GTX 580 (1,5 GB) vs. GTX 580 (3 GB)

[adonys]

yes, but that doesn't mean they can't have both GPU accessing the whole memory (as the memory is on the same card, the accesing speed should be faster than accessing the other GPU's memory via a SLI link).

is highly improbable, but as none of us really knows the way the hardware of dual GPU works, we can't have a say in this.

that's why I said we need to dig this up.

[Porksmuggler]

Originally Posted by adonys

but as none of us really knows the way the hardware of dual GPU works, we can't have a say in this.

Each GPU maintains it's own frame buffer, rendering data is duplicated in each frame buffer. VRAM is not pooled.

[nigelmcelwee]

Originally Posted by jimbop

Apologies - I have just checked and my GPU usage drops from 99% to ~50% in low flight over London, presumably as the CPU struggles to deal with all the buildings. Bring on the patch!

Yeah but the GPU should not be goign at 99 percent the whole time. I have a GTX 580 GPU and it stays pegged at 99 percent the WHOLE time the game is running and it has almost fried my card several times with temps close to 100 degrees celcius.

[madrebel]

Originally Posted by louisv

SLI stands for Scan Line Interleaving...

no this is what sli used to stand for. sli now = scalable link interface.

[Ataros]

I can not find any program to monitor vram usage of an ATI card. MSI Afterburner, GPU-Z do not show it for an ATI. Any suggestions?

[adonys]

try AIDA64, as the others did in the other thread.

[jimbop]

Originally Posted by Ataros

I can not find any program to monitor vram usage of an ATI card. MSI Afterburner, GPU-Z do not show it for an ATI. Any suggestions?

Edit: beaten to it!

[madrebel]

yes it does you just have to setup realtime monitoring.

evga precision and msi afterburner are just different versions of rivatuner.

here is a link
http://www.vgaforum.com/showthread.p...nitoring-Guide

or just google rivatuner monitoring guide and figure it out from there. it isn't terribly difficult.

if you want to get real fancy then you can setup a profile that sets the clocks to default when no 3d apps are running and another profile to apply an overclocked profile when a 3d app is running and have them apply automagically.

*edit* the pics i posted on page 2 show in the upper right hand what real time monitoring looks like. it puts an overlay on the screen when a game is running. you can change that position around too if you like. you can also change the color too.

[Codex]

Originally Posted by Buchon

There a lot of confusion in this thread about how SLI/Crossfire work.

SLI/Crossfire cards and systems dont share VRAM between GPUs.

That's not entirely true. It depends on how the developer has set up the buffers in DirectX. While yes they physically don't share memory, but with DirectX you can map the memory to appear as one huge chunk.

http://msdn.microsoft.com/en-us/libr...=vs.85%29.aspx

[madrebel]

Originally Posted by Codex

That's not entirely true. It depends on how the developer has set up the buffers in DirectX. While yes they physically don't share memory, but with DirectX you can map the memory to appear as one huge chunk.

http://msdn.microsoft.com/en-us/libr...=vs.85%29.aspx

no, you can't. each GPU has X memory. gpu1 can't access gpu2's memory. if GPU2 even wanted to access GPU1's buffer then this would slow down the frame draw process which is why it isn't done.