Nice post Xanthe,
I am surprised even with underclocking your 3 7950s you can get by with only a 850psu. These cards supposedly draw up to 300w under full load (depending on what coin you mine). Then trying to power other peripherals make it seem like your power supply would be running at 100% capacity(or more). Even simple calculators would recommend at least at 1000 for those three cards.
I am surprised even with underclocking your 3 7950s you can get by with only a 850psu. These cards supposedly draw up to 300w under full load (depending on what coin you mine). Then trying to power other peripherals make it seem like your power supply would be running at 100% capacity(or more). Even simple calculators would recommend at least at 1000 for those three cards.
Thanks for the kind words.
The Asus power supply calculator that you linked is nice but it provides very high estimates. This is not an entirely bad thing because of course, as you pointed out, power supplies are typically most efficient around 50% load and it's always better to have a larger power supply than you need.
My motherboard and CPU are quite efficient and I have the CPU underclocked and wayyyyy undervolted. If I unplug my 7950s and plug in an old PCI videocard then boot to desktop, the system idles at only 55 Watts.
sorry i ment to say i have 3 7950s runing at 630kh each
edit 1050 core 1250 ram 1.050v core 55% fan
edit 1050 core 1250 ram 1.050v core 55% fan
Thanks for posting this info, I was just about to ask.
Your setup seems to be running nicely. Have you tried running your memory even lower than 1250 (i.e. ~900)? I was able to drop over 40 watts by taking the memory down from 1250 -> 900 and I didn't lose any hash rate.