Finished the 2 smaller systems with two ATI 7970 each today: Different design objective vs. the green machine.
The Gigabyte 7970 can't be packed as dense as the Titan's. Can't cope with the heat in the case. Instead of one PC I build 2 simpler ones with the entry level CPU only targeted to drive the GPUs, no CPU folding: Intel Celeron G1610 ($50). This CPU is more then capable to drive the two 7970 cards. During normal operation, CPU load is at 16-20% (@1.8 GHz), during checkpoints CPU is at 60%.
Power (measured on the wall outlet)
idle: No GPUs. 30 watt
idle: 2 GPUs. 80 watt
FAH: 380 watt
temperature:
both GPUs are now at 60-65C - much better than the 100C in a 4GPU setup I had previously.
Performance:
http://www.pbase.com/andrease/image/...9/original.jpg
CPU load - It wouldn't have made much difference to add a higher performing CPU from a PPD perspective, but the energy efficiency would have gone down.
http://www.pbase.com/andrease/image/...0/original.jpg
Andy