60w enough for undervolted sempron 140, 785g and ssd? YES!

[porkchop]

specs are:
sempron 140 [email protected], [email protected]
gigabyte ga-ma785gm-us2h stock
kingston v series 64gb ssd
kingston value ram ddr2 2x1gb

would a picopsu-80 and a 60w brick be sufficient?

a quick search on spcr has given me conflicting numbers. i've seen 41/47w idle/load and also 45/75w idle/load, the latter had no mention of undervolting though and they also used different components (no discrete gpus).

any help is much appreciated.

[Vicotnik]

I think it would work fine. With 740G, Sempron 140 @ 800MHz 0.75v, a 3.5" HDD and a picoPSU 120W I got 38W idle. Didn't do any full load measurements but they were not far higher since I kept the CPU at constant frequency and voltage.
If you run into problems you could perhaps underclock a little.

[HFat]

Power consumption at load can increase quite a bit even if the clock and voltage doesn't change. I wouldn't try to run a mainstream system on 60W, even underclocked and undervolted. It might work if it's a good brick that performs over its spec. But I'm not knowledgable enough to know what I could potentially damage. It might also be unstable.
Some Kingston SSDs have a higher load power consumption than most by the way.

[porkchop]

i know i'm cutting it close here, but the plan is to use the pico for a zacate system later so 60w is plenty.
38w idle seems pretty high, from memory there was a thread when the 785g chips first came out and someone undervolted an athlon ii 240 with my motherboard and almost broke 30w in idle (with a laptop hdd).

i guess this is a pretty good opportunity(read: excuse) to buy myself a power meter

[andymcca]

My Sempron 140 + 785G box does not pass 60W continuous when underclocked and undervolted. That was with a USB flash drive, but I imagine an SSD should not draw much more.
Edit: also I agree with Vicotnik that idle/load power does not seem to change very much when using a static underclock/undervolt.

[ces]

i know i'm cutting it close here, but the plan is to use the pico for a zacate system later so 60w is plenty.
38w idle seems pretty high, from memory there was a thread when the 785g chips first came out and someone undervolted an athlon ii 240 with my motherboard and almost broke 30w in idle (with a laptop hdd).

ElectroDaucus on this board has a dual core Intel that uses something like 26w at idle.

[loimlo]

Frankly, I don't think continuous load is an issue. Instead, power-on peak value would concern me given HDD may draw up to 20W during such a short period of time! But any quality power brick should sustain a short period of power-on load.

All in all, try to find a quality 60W/80W power brick which is far more important that pure power rating .........

[porkchop]

another advantage of using an ssd - no big spikes in power consumption

i'll probably jump the gun on a picopsu-80 and an edac ea1050(link) 60w power brick, the edac isn't as good as the one from minibox but it's cheap and readily available.

will report back if/when i get it together.

edit:
found something: viewtopic.php?t=58228
athlon ii x2 240 undervolted, 785g motherboard, picopsu-120 and 120w brick, 2gb ddr2 ram, 2.5" hdd and an odd- 30w idle, 45w cpu load.

[porkchop]

it lives!

seems fine so far, been stressing(orthos) for a bit with no problems. only real concern is the 12v line which is drooping to 11.46v at the lowest and stabilising at 11.58v, it's within spec... just. it idles at 11.78v.
brick efficiency seems very good, at load it only gets warm.

updates:
drooping has reduced significantly after some usage to 11.97v/11.78v at idle/load, perhaps since it has been 'burnt in'.
brick does get warmer than i first thought, i guess it needs some time to heat up. it's still not bad, feels about 35-40c, i've put a heatsink under it just for kicks.