7970/7950 crossfire performance better than 7970 OC'd

wingclip

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Aug 9, 2012
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Hi folks,
I presently have a MSI HD R7970BE OC edition graphics card installed on my computer. My present graphics card does a hell of a good job overclocked at1045/1450 and 1.65v. However, when I run the card that fast, I usually run it for at least three or four hours minimum and I’d like to take a little pressure off of it.

Therefore, I’m thinking that I may be able to get as good, if not better, results if I were to run a crossfire configuration without overclocking either card.

Finding another MSI HD R7970BE OC edition in decent shape and within my expense budget isn’t easy. I have found some and even some that are brand-new. However, almost every one of them is priced over my max budget.

I purchased my present 7970 used about a year ago. The seller claimed he had it for abaout6 a year and it was in very good condition. He was right, It was in very good condition and I bought it for $140.

Anyway, I’m thinking of possibly installing a 7950 as the second card because I found someone who was selling an MSI HD 7950 3GB GDDR5 “Twin Frozr” at a good price. Like my present card, the 7950 has 3 GB of memory and is also a GDDR5.

After I checked some old topics in Tom’s hardware archives, I found that it would be okay to run a 7950 in a crossfire configuration with the 7970 card.

However, what I’d like to know is; would I get better performance from these two in a crossfire config, (at their default clock speeds), than I would running my single 7970 at an overclocked speed I listed above?

It’s possible that I would “mildly” overclock both of the cards at some point but for now, I’m speaking about working with just the default clocks in crossfire configurations.

The default clocks of the 7950 are core: 880mhz and Mem: 5000mhz
The default clocks of the 7970 are core: 950mhz and Mem: 5500mhz
Thanks,
Rich
 
Solution
As it's been stated already, a crossfire setup between a 7970 and 7950 will run at the performance of the 7950. If you overclock the 7950, you'll bring performance of both cards up, as the two will both operate closer to the limit of the 7970. The 7950 will always be running close to max. If you're concerned about heat, set the fan speeds yourself. There's nothing that says you have to stick with the default fan speeds which are usually tuned to favor less noise and allow the cards to sit in far more heat than necessary. The top card will never have better than 100% fan, so worst case scenario, you can always run with that if you don't like how hot it runs.
it will run it at the level of 7950 but crossfire will be always better than one card for some games (some games don't support it). The main problem you will face is heat. One card will be next to each other running hot. I had 2 x 7950 and one of them(top one, least air flow) died from heat. Also make sure your PSU can support 2 cards.
 
As it's been stated already, a crossfire setup between a 7970 and 7950 will run at the performance of the 7950. If you overclock the 7950, you'll bring performance of both cards up, as the two will both operate closer to the limit of the 7970. The 7950 will always be running close to max. If you're concerned about heat, set the fan speeds yourself. There's nothing that says you have to stick with the default fan speeds which are usually tuned to favor less noise and allow the cards to sit in far more heat than necessary. The top card will never have better than 100% fan, so worst case scenario, you can always run with that if you don't like how hot it runs.
 
Solution