Brand new rig fails to properly utilize it's two HD6950

[sodapop]

The hardware:

MB: P8P67M Pro Newest bios
CPU: I3-2100
GPU: Asus 6950 1GB Factory bios, no overclocking
SSD, 6gb ram.

The problem:

When I run any miner (hashkill, phoenix, diablominer), or any combination of miners, I either get around 50-75% utilization of both cards, OR, I get 99% utilization of one card.

Basically, I either get sub-optimal performance from both cards, or I get expected performance from one card while the other is entirely starved. This happens at random. If I do get a stable 75%/75% from both cards, it will eventually (maybe after hours) turn into either 99%/0% or 0%/99%.

I am running 64-bit ubuntu, 11.04 and Stream SDK 2.4. The two PCIe slots the cards are connected to has x8 speeds according to the motherboard manual. I have installed one crossfire bridge (otherwise I can't use the 2nd card in linux). The temperatures are fine. My CPU utilization is almost nothing. Both cards easily do more than 300MH by themselves. I do not understand where the bottleneck is.

Any help with this would be highly appreciated. I'll gladly give 0.1-1btc tips to information that makes a difference.

[drawoc]

Could you post your Xorg.conf? You can find it at /etc/X11/xorg.conf

[sodapop]

Code:

Section "ServerLayout"
	Identifier     "aticonfig Layout"
	Screen      0  "aticonfig-Screen[0]-0" 0 0
EndSection

Section "Module"
	Load  "glx"
EndSection

Section "Monitor"
	Identifier   "aticonfig-Monitor[0]-0"
	Option	    "VendorName" "ATI Proprietary Driver"
	Option	    "ModelName" "Generic Autodetecting Monitor"
	Option	    "DPMS" "true"
EndSection

Section "Device"
	Identifier  "aticonfig-Device[0]-0"
	Driver      "fglrx"
	BusID       "PCI:1:0:0"
EndSection

Section "Screen"
	Identifier "Default Screen"
	DefaultDepth     24
EndSection

Section "Screen"
	Identifier "aticonfig-Screen[0]-0"
	Device     "aticonfig-Device[0]-0"
	Monitor    "aticonfig-Monitor[0]-0"
	DefaultDepth     24
	SubSection "Display"
		Viewport   0 0
		Depth     24
	EndSubSection
EndSection

[drawoc]

Looks like you only have one card set up - not 2.
Try running:

Code:

aticonfig --initial=dual-head

and restarting.

[Sideways]

simple things first, are you pointing your miners at different cards? ie, when you run just polcbm it will tell you that you have to give it a device, usually 0 and 1. You then have to start each miner with a -d0 and a -d1 to use the second card. I like to open a separate terminal for each miner so I can watch them, and usually have 1 or 2 more open to watch temps, etc.
Also, if it's a dedicated miner (not a part time gamer) take out the xfire bridge, it doesn't help ( maybe even hinders.. ) mining.

edit:
now that I've thought about it and come back, I'm thinkin it is the xfire setup.. I'd start there by taking it out.

[Oldminer]

Check that your not running 1 of the cards @ PCI-Ex 1 x in the BIOS

[sodapop]

I can't say what the problem was, but I am now running the exact same setup on Kubuntu, and I get 99% load on both cards and a decent 650MH with no overclocking.