This is my first post to this forum.
Windows 7 64bit
2x hd5850 Sapphire Extreme OC to 850MHz
Phenom x2 550
GuiMiner - 690MH/s total and still can surf on the internet, wach movies not affected by mining. No shut downs also.
I would not worry about high CPU Ussage, the only think You need to worry about is Your electricity bill
. To reduce power consumtion of my CPU I did that:
1. Go to GUIminer ( if You use one ) and set a CPU affinity to one core and the same core for each GPU You use. That should Reduce CPU usage to around 50%
2. Go to CCC and than to "Power" or "Performance" and "CPU power"
3. Reduce CPU processor speed to minimum. In my case from 3100MHz to 800MHz. Or You can reduce CPU speed in BIOS as well.
4. That's allResult:Before 1st step. Using 2 Cores, 100% CPU usage, 3100MHz CPU frequency. CPU consuming 86,4W - that's quite a lot.
http://i54.tinypic.com/r905g6.jpgBefore 2nd step. Using one core for 2 GPU. 50-51% CPU usage, 3100MHz CPU frequency. CPU consuming 86,4W. One core is free now so everything else goes faster. NO drop in MH/s.http://i52.tinypic.com/20keqdt.jpgAfter third step. Using 1 Core for both cards. 50-51% CPU usage. 800MHz CPU frequency. NO drop in MH/s. 24W CPU power consumption http://i52.tinypic.com/2uqdcao.jpghttp://i55.tinypic.com/2j60j9h.jpg
Savings? 62,4W on two cores. If You have more, than more savings
62.4W -> 1.5kWh a day - > 45 kwh a month. In my case that's about 5-6 pound per month.
I hope I helped.
There is also few more things to do to reduce general power consumption of Your computer, disable what You don't use in bios, reduce ram Voltage etc.