After carefully reading the numbers presented on previous page, we decided to make the following changes to our setup:

• System 1: Remained as before.
• System 2: Replaced the GeForce GTX 260 with a GeForce 8800 and uninstalled the SMP client. Power consumption dropped from 202 W (145.44 kWh or USD 17.81/month) to 185 W (133.20 kWh or USD 16.31/month). Maximum performance changed from 5,873 points/day or 176,190/month to 5,120 points/day or 153,600 points/month. Our points/kWh index for this machine is now 1,153 (from 1,211).
• System 3: Decommissioned.
• System 4: That was the source of our high consumption because it was using two ATI video cards (Radeon HD 4870 and Radeon HD 4850). We removed the ATI video cards and replaced them with one GeForce 8800 GT and one GeForce 9800 GT. We also replaced the CPU from a Phenom 9700 to an Athlon X2 4600+, which allowed us to save some watts, as we are not going to run the SMP client. We also replaced the OCZ ProXstream 1,000 W power supply with a Zalman ZM-600HP unit. Here was where we saw a huge difference in consumption and performance. This system as it was before was consuming 430 W (309.60 kWh, USD 37.92) and producing a daily score of 4,738 points and a monthly score of 142,140 points. After the changes, power consumption decreased 41% to 254 W (182.88 kWh, USD 22.40) and our score doubled, going to 9,485 daily points or 284,550 monthly points! Our points/kWh index increased from 459 to 1,555.
• System 5: Even though this machine was the one with the best efficiency index before, it was also the most expensive to run (468 W, 336.96 kWh, USD 41.27), as it had three video cards and a very high-end CPU. So we decided to shut it down and use the two GeForce 8800 cards on the other systems and put our GeForce GTX 280 back in our closet.
• System 6: We decided to use our Playstation 3 only to play games or watch Blu-Ray movies. It was not efficient to keep it running Folding@Home.

We have now only three systems running Folding@Home, but consumption is now 560 W (403.20 kWh) from 1,565 W (1,127 kWh), what will cost us USD 49.38/month instead of USD 138/month. That is a 64% decrease.

Or course performance decreased. We will be now making 17,439 points/day or 523,170 points/month from 30,715 points/day or 1,063,590 points/month, so performance decreased 43%.

The beauty, as you can see, is that performance and consumption didn’t decrease at the same proportion. We had before a points/kWh index of 944 – i.e., we were making 944 points at Folding@Home for every kWh consumed – which increased to 1,297. So our efficiency increased 38%!