Legit Reviews

Hey, duders! This is my rig:

CPU: CORE i7 920 2,67 GHz
MB: ASUS P6T
MEM: CORSAIR DOMINATOR 6 GB DDR3 1600 MHz
PSU: Thermaltake Toughpower 850W

First off, when the speed of GDDR5 memory displays 1000 MHz and the webstore's specifications tells you it is 4 GHz, is this because GDDR5 has a quad effective speed?

My real question is this: When I check MEMORY SIZE under GRAPHICS HARDWARE in ATI's CCC it tells me I have 1024 MB. This should be 2048 MB, yes? It is a 2 GB card after all. I've tested this with catalyst 10.8 in both Windows XP and Windows 7 with the same result. The funny thing is that DXDIAG in XP tells me I have 1024 and DXDIAG in Win7 tells me I have 716 ??? What is the issue here? Can it be a driver issue?

Any help would be greatly appreciated!

Honestly you're fine. Crossfire/SLI setups will only see and use what one GPU has for memory..Dual GPU cards(like the 5970 and the GTX 295) are the same way as essentially, they are two GPU's hardwired into Crossfire/SLI in one single card. Your card does have 2GB, for each GPU. But in Crossfire, it will only use/see 1GB.

As far as DXDIAG goes, I never use the info it shows as it's shown wrong usually(or it's just compiled differently). Heck, it even says I have 4GB total memory on the graphics section, but I have 1.5GB on each card technically.

Thanks

Then in which cases does one actually use 2 GB of memory with dual GPU cards? Also, what benchmarking tool (other than those made for specific games) would you recommend to best measure performance?

impsterdude wrote:what benchmarking tool (other than those made for specific games) would you recommend to best measure performance?

3DMark Vantage performance preset, you can compare your results against thousands of other cards/setups on hwbot just set the results filter to stock and or single card

impsterdude wrote:Then in which cases does one actually use 2 GB of memory with dual GPU cards?

When each GPU has 2GB basically. (like hte 4GB version of the 5970) <----sadly those like a grand a piece though

skier wrote:3DMark Vantage performance preset, you can compare your results against thousands of other cards/setups on hwbot just set the results filter to stock and or single card

Thanks for the tip

InspectahACE wrote:When each GPU has 2GB basically. (like hte 4GB version of the 5970) <----sadly those like a grand a piece though

Yeah, I know. That's twice the price. How much gain in FPS would you get with the 4GB anyway. Can't imagine it's worth it.

The only time you will need a 4GB frame buffer is at insane resolutions and detail settings (i.e. 2560x1600 and up). Otherwise it will be wasted. You can monitor GPU memory usage with GPU-Z under the Sensors tab.