Poor Performance HD4850's in Crossfire X

[overvolts 0]

I seem to be getting bad performance with my two HD4850's in crossfire. Also, have an issue with freezing for a second or two stuttering at random. I have another issue with shadows, when I set the detail to high, the shadows are all blocky looking, when I set the detail on normal, shadows render correctly then. I am using the Hotfix drivers. Anybody else with this issue?

System Specs: 5000+ X2 @3.3Ghz, DFI 790FX M2RS, Ballistix DDR800, Sapphire HD4850 (Crossfire X) X-FI Xtremegamer, Samsung 160Gb in RAID 0.

[hicks88 0]

most people experience worst preformance in arma when running cards in crossfire or sli, try using just one and see how you go

[Dwarden 1125]

contact AMD.ATI and request optimal CrossFire/CrossFireX profile for ArmA!

w/o that being part of drivers it's pain to use CF/CFX

[odjob 0]

Have you tried Catalyst 8.7?

Some seems to have problems with those but my machine seems to run better with theese than with 8.6 hotfix.

Mine=HD4870, Vista32.

[berghoff 11]

I experience same performance as with running just one card with latest driver.

[overvolts 0]

I've tried the latest 8.7 Catalyst drivers. I am getting better performance than before. I get best framerate with crossfire disabled. Seems to be crossfire makes performance worse. I will try contacting amd.ati for the optimized profile and see if that helps me with crossfire performance.

[kklownboy 43]

to use CF in Arma, I had to rename the ARMA.exe to Fear.exe .Back when i used HD2900xt's in CF, it would double my frame rate over a single 2900. If you run into issues it can help to Delete your ARMA.cfg And when you start ARMA be sure to be in CF in the ATI control panel, and use Fear.exe to start. Now i am on a 9800gfx X2, and use both cores. works fine, gives more fps than in single core mode, using the nvda control panel 3D settings, and creating my own profile. CF and SLI work in ARMA and give you a good boost.

[-=seany=- 5]

kklownboy: are you using vista or xp? I have vista and 2 9800gtx and Arma runs really well, 72 fps all settings maxed except AA. But unfortunately it doesn't last long, my fps will suddenly go really bad while looking at a tree or a bush, until I alt tab out and back again, then my frames are high again for a little bit.... :/

what profile settings are you using?

I also am dual booted with xp64, wich seems to not have this problem, but I have another texture loading issue with XP64 that doesn't happen in vista....what a PITA

[gL33k 0]

overvoltage ; any update on issue ?

i would like to know how good CF is with arma, because i plan to buy a 2nd hd4850 too .

1 card is good, but 2 might make me able to play in very high res , like 2048x1536. crystal clear picture

[kklownboy 43]

@seany; XP-175.x and 177.x drivers. In the nvda CP 3D settings, you can set up profiles, pick multigpu ect.

@gL33k; I think 2048/1536 will be a slide show with 4850s in CF. Great new cards but still not enough for Uber highres and high settings. I run 1600/1200 Vsync on with mostly high and veryhigh settings...SP. MP, i lower till its smooth depending on the amount of AI ect, Oh i rarely use higher than 1000m view distance. And will lower it( if server allows) to 300m in super action urban combat, crazy AI . I have seen the island at 5000m 10000m ect... but you cant hit any thing at that distance anyways, smooth 60fps 80% of the time is much better to me than huge view distances. The last 20% can have the Ortego urban spots of in the teens FPS!!! and the dreaded microstutter, low view distance helps with that.

[-=seany=- 5]

Thanks Kklownboy.

After a bit more testing it appears that the problem is not related to SLI, its just Vista and Arma. With SLI disabled the same thing happens, random performance when looking at foliage. Weird thing is I had vista installed a couple of months ago and it ran like a dream. Maybe its the 177.79 drivers, ill try 175.19.

[overvolts 0]

Well I've given up on the Crossfire for now, just disabling crossfire when I play ArmA. Going to wait until the drivers mature a bit and get added game support.

@gL33k If you are wanting to play at 2048x1536 resolution, then a 512MB card is not the one for you. 512MB cards are only good up to 1680x1050 resolution and above that a 1Gb card is needed. I suggest you cheack out Sapphire has a HD 4850 model card with 1Gb of memory instead of the 512Mb. Sapphire HD4850 1Gb product page.