second gpu for crossfire

ScopeThaGecko

Honorable
Mar 17, 2013
47
0
10,540
Heey guys,

i am looking for a nice upgrade to my gpu. i know i need to upgrade my psu first, but i am actually planning to upgrade that at the same time and also get a ssd. i am getting the:
- XFX ProSeries 850 Watt, 20+24 Pins
- Samsung 840 Series Full Kit 250 GB SSD

but next to that i also really want to get a second gpu for heavy gaming. right now i am running:
- i7-3770k @4.2Hz ~ CPU
- XFX AMD Radeon 7950 BE DD @1.0GHz ~ GPU
- Corsair Vengeance 16GB @1.6GHz ~ RAM
- ASRock Extreme 4 ~ MoBo
- Seasonic M12II-520 Bronze 520 Watt, 20+24 Pins ~ PSU
- Seagate Barracuda 1TB HDD 7200RPM 32MB/s ~ HDD
- Scythe Mugen 3 PC Gamer Edition ~ CPU cooler
- Spire X2 ~ Case

now here's the deal, i want to get asecond gpu. now i just don't know wich to choose. i am torn between getting the:
- XFX AMD Radeon 7970 BE DD
and the
- XFX AMD Radeon 7950 BE DD

i am going to run these in crossfire. now wich one is better to get, money is not really such a big thing in this upgrade. my main question actually is: would a r7970 also perform well in cfire with a r7950 or will it suffer from a performance drop since it is not the exact same card, or would a r7950 outperform the 7970+7950 setup?
do tell me if it is better to get the r7950 over the r7970 if the 7970+7950 looses too much in performance.

hope you guys can give me the answer.

Sincerely,

Gecko
 

bcarlo25

Honorable
Oct 9, 2012
58
0
10,640


No problem! Enjoy the new card when you get it!
 
If you've ever tested this with monitoring tools, you'll learn that they operate at their own clock speeds and the idea of the faster card downclocking to the weaker card is a myth. I've tested this with a number of AMD and Nvidia cards. They do not sync up unless you modify their clocks with software.

Further more, AMD cards do not meter their frames so they are evenly distributed, so it would be wise to use two cards of the same type and speed, or you will make the Crossfire lack of metering even worse.
 
Mar 17, 2013
55
0
10,660


Well thid clears up a lot :)
Thanks
 

bcarlo25

Honorable
Oct 9, 2012
58
0
10,640


Sorry I should have explained it better! I didn't mean to imply that the faster card would down clock. I just wanted to let you know there would be no performance gain over identical GPUs.
 
Mar 17, 2013
55
0
10,660


Mate dont sweat it i was being serious not sarcastic ;)