Crossfire slower performance than single card :(

I know similar have been posted alot around, and i hope i am not being annoying, but so far haven't found a similar enough case with any useful to my situation clue .

I have set up a crossfire of two 5850 and i think ( i am not sure ) that after installing cats 11.10 (after a good cleaning) performance with crossfire enabled droped to half with this specific game DCS A-10C ( . I havent had the chance to check it with other applications, but i think performance of CF now is obviously lower than it was with even cats 11.9 with the same application.

Performance was normal so it didn't occure to me to check if CF works ok . but after 11.10 performance droped a lot so i checked how it is with CF disabled and indeed single card framerates are double the least ...

Tried 11.9 again and 10.12, no difference ...

Did a test with 3Dmark 11. With CF disabled i got a somehow lower score than the last single GPU score of this system with older drivers. Enabling Crossfire gave me though almost the same score as my previous crossifre (older drivers) top score for this rig, around 7000.

Odd behavior .......

Just for the heck of at least possibly getting to know what is the cause of crippled CF performance in this simulator , i overclocked my CPU to 4Ghz and rerun the same tests. Actually scores and smoothness were better in both cases but at the same ratio again (CF worst than single GPU in DCS A-10C, better in 3Dmark11) ... (the stability though of the system impressed me given the current PSU).

Any suggestions ?

4 answers Last reply
More about crossfire slower performance single card
  1. What's your specs and native resolution?
  2. Darn, sorry, i thought i had setup a signature with that . Should be up now. Native Res is 1920 x 1200
  3. i7-880 | 8 Gb G.Skill Ripjaw 1600 DDR3 | 2 x HD 5850 | ECS P55H-A Black Series | Enermax Liberty Eco 620 | OCZ Vertex II 180 | G.Skill Falcon 64 | 2 x 2T WD Green | WD 500 Blue | HP ZR24W
  4. test
Ask a new question

Read More

Radeon Performance Crossfire Graphics