Using igp
2400+ Thorton at 140 * 15, 1.65 vcore
Arctic Cooling Copper Silent TC
80mm Panaflo L blowing on nb hs
1x256 ram
Maxtor DM+8 30g hd, no fd or cd
Win 2K SP4
Ambient temp 27*C (80*F)
All components uncased
Code: Select all
Zalman ZM300A-APF Seasonic SS-300FB Seasonic SS-300FS Fortron FSP300-60PN
Watts Amps Watts Amps Watts Amps Watts Amps
Idle 61 .53 49 .42 49 .74 62 .93
Folding 117 1.01 101 .87 100 1.42 117 1.63
Using igp
P4 2.6C, oem speed
Swiftech MCX478-V HS
PCP&C 92mm 1,600 rpm hs fan
80mm Panaflo L blowing on nb hs
1x256 ram
7200.7 80/8mb hd, no fd or cd
Win 2K SP4
All components uncased
Code: Select all
Seasonic SS-300FB
Watts Amps
Idle 43 .38
Folding 1 88 .76
Folding 2 with ht 94 .80
Unplug hd power, at idle 37 .33
Data from Kill A Watt - p3international.com. Zalman 300A and Seasonic SS-300Fb (ver A2) are active PFC which appears to be the reason for the disparity between the watts/amps ratio above. An explanation of power factor. A layman's (like me) explanation would be that the electrical design of the non pfc psu's actually cause power to flow back into the power line during the ac cycle from positive to negative. It seems to follow that the amps shown on the Kill A Watt are the peak amount of power used and the watt usage reflects this flow-back of power. Whether the watts value is calculated by the Kill A Watt or determined some other way, I have no idea. If it all sounds a little like witchcraft, well, it does to me too.
As a practical matter, I'm not sure how much active pfc matters, other than the more advanced psu's from Seasonic have a clear advantage in lower power use. However, for now anyway, it doesn't appear that the advantage is so great that trash canning an older psu in favor of an active pfc psu is indicated.
All tests were run twice over a time span of about 3 hours. The second tests resulted in differences of zero to about 2%, perhaps because of a slight temperature change. The 80mm nb fan sits on top of the pci slots and is sort of aimed at the nb hs to cool it. The motherboards are either sitting on top of a cardboard box or piece of plywood and with practically no airflow over the nb hs's, I was getting daily lockups until I added the fans. Note that unplugging the fan, with the Kill A Watt connected, no noticeable reduction in power use could be detected.
My previous postings of amps using a digital multimeter turned out to be about 10% less than the same setup measured by the Kill A Watt. The previously posted watt usage, calculated by amps * volts was way off as my calculations didn't consider "power factor" as there was no practical way to measure it with a dmm. Hey, we're all learning here.
M
Edited for clarity