Crossfire and the 3870

[KCB]

Hi All,

I have recently purchased a system with the following bits N pieces.

Intel Core 2 Quad Q6600

Gigabyte GA-X38-DS5 M/B - X38, 1600MHz FSB, DDR2-1066MHz

2 X PowerColor HD3870, 512MB GDDR4

Currently I have an iCute case with a 500W PSU but am waiting for my
Zalman ZM750-HP 750W Power Supply to turn up in the mail.

The issue I have is that when I enable the Crossfire in the CCC
console the reported frame rate drops in COD4 and the game seems to
run slower. Doesnt seem to have any marked improvement in Crysis
either.

Could it be that the second slot is running slower and when enabled
drags the system down to a slower speed? I couldn't find anything in
the BIOS to alter the speed for the PCIe slots.

Perhaps the PS is not providing enough power for both cards and so the
3870 backs off to some low power mode?

I have downloaded the latest ATI drivers, or at least I think so. The
Powercolor web site doesn't seem to even have a branded driver set on
their site.

Anyhow, any ideas would be appreciated.

Thanks in advance!

Mike

7.11 are the latest drivers from ATI. What version of COD4 are you
using (patch)? There is a setting for dual video cards in the Options
menu. Did you enable it there as well as in CCC? As far as Crysis, ATI
has a 'hotfix' available that is supposed to deal with corruption and
performance issues. Maybe try that?

 

[Mike Smale]

Hi All,

I have recently purchased a system with the following bits N pieces.

Intel Core 2 Quad Q6600

Gigabyte GA-X38-DS5 M/B - X38, 1600MHz FSB, DDR2-1066MHz

2 X PowerColor HD3870, 512MB GDDR4

Currently I have an iCute case with a 500W PSU but am waiting for my
Zalman ZM750-HP 750W Power Supply to turn up in the mail.

The issue I have is that when I enable the Crossfire in the CCC console
the reported frame rate drops in COD4 and the game seems to run slower.
Doesnt seem to have any marked improvement in Crysis either.

Could it be that the second slot is running slower and when enabled
drags the system down to a slower speed? I couldn't find anything in
the BIOS to alter the speed for the PCIe slots.

Perhaps the PS is not providing enough power for both cards and so the
3870 backs off to some low power mode?

I have downloaded the latest ATI drivers, or at least I think so. The
Powercolor web site doesn't seem to even have a branded driver set on
their site.

Anyhow, any ideas would be appreciated.

Thanks in advance!

Mike

 

[Tweek]

Hi All, ....
Anyhow, any ideas would be appreciated.

Thanks in advance!

Mike

Try disabling Catalyst A.I. I am running X1950XTX Crossfire, and disabling
Catalyst A.I. gives me much smoother Crossfire performance in all direct3D
games. With Catalyst A.I. on in Crossfire mode, performance appears the
same or worse than with a single card. I am playing at high resolutions
(1920 x 1200 or 2560 x 1600) so that might have something to do with my
experience. Try it, it's worth a shot...