Does anyone know or can give any evaluation of the revenue for one of the sportbooks available for bitcoin?

Which sportsbook is the largest by revenue?
Please provide your data source.

Hi all,

I have a machine with 2x5970 cards .
I'm using LinuxCoin and phoenix miner with deepbit pool.
I run 4 pheonix miners using the following command:

./phoenix.py -u http://user:password@deepbit.net:8332/ -q 6 -k poclbm VECTORS BFI_INT AGGRESSION=12 WORKSIZE=128 DEVICE=0

With DEVICE going from 0 to 3

When I only run devices 1,2 and 3, each run on 305 MHash/s
When I add device 0, It runs on 305 MHash/s but the rest drop to somewhere between 220 and 290

I've increased the fan speed to 70%, and the temperatures seem fine (less than 76 Celsius).
I've used aticonfig --lscs and saw that Crossfire seems to be disabled.

Do you know why I can't get all devices to run on 305 MHashs/s ?