I have been having power blips recently and decided to to invest in a UPS for my desktop. I have an AMD 945 quad CPU and an ATI 4870 GPU. Well measuring the watts used during different configurations I discovered that if I set the preferences to use 90% of the processors then my watt usage fell well below 300 watts, if I lower the % of the processors to 60%, effectively only using 2 cores, then my wattage jumps up to the 320-335 range (exceeding a 550kVa ups range). My conclusion is that the GPU was being starved for data because there were insufficient CPU cycles to supply it with data. Any other thoughts and/or ideas?

The long and short of it is that using to much CPU slows down GPU processing.
And yes I purchased a 1000 kVa UPS.

I have been having power blips recently and decided to to invest in a UPS for my desktop. I have an AMD 945 quad CPU and an ATI 4870 GPU. Well measuring the watts used during different configurations I discovered that if I set the preferences to use 90% of the processors then my watt usage fell well below 300 watts, if I lower the % of the processors to 60%, effectively only using 2 cores, then my wattage jumps up to the 320-335 range (exceeding a 550kVa ups range). My conclusion is that the GPU was being starved for data because there were insufficient CPU cycles to supply it with data. Any other thoughts and/or ideas?

The long and short of it is that using to much CPU slows down GPU processing.
And yes I purchased a 1000 kVa UPS.

This is common with gpu's at other projects and Nvidia's here, but I have not seen it with ATI gpu's here before.

One thing to remember is that the batteries in those UPS's need replacing periodically, so save your pennies for the next 2 years or so.