Swap Manchester A64 X2 for Sempron D0 or A64 single core?

[sloeer]

I'm trying to decrease the idle wattage on my asrock dual sata2 socket 939 system. Currently the bare system with a vcore locked (1.1V) X2 3800+ is idling at about 95W, regardless of clock speed and cool n´ quiet. I don't care about the performance, so it should be possible to lower this without having to buy a completely new system.

My question:
Should I go for a Sempron D0 (no cool n´quiet) which can undervolt much better than my current cpu?
or
Should I go for a regular single core athlon, like venice 3500 or something?
or
Is it pointless since the idle wattage of all of them is about the same.?

Thanks

[Greg F.]

I have some kind of single core in an older machine. It is very slow when updating windows or just doing anything. Personally I will never have a single core anything again. Even a NAS, or anything, needs to have updates and the single core I had was frustratingly slow.

[Klusu]

Can you undervolt your manchester?
Sempron is not better. You certainly want cool'n'quiet.
Single core would draw less.
Another manchester, same model may draw quite a different amount.

[dhanson865]

The only thing that makes sense to me would be going to an AM3 motherboard (maybe 780 or 785 chipset) with a C2 or C3 stepping Phenom CPU.

Socket 939 never got the support it deserved when it comes to updated CPUs.

The lowest power 939 CPUs are

"Venice" (E3 & E6, 90 nm) 1.4v or 1.35v (mostly in the 2800 to 3000 model range gotta be careful you don't grab another 89W unit)

and

"Winchester" (D0, 90 nm) 1.4v (mostly in the 2800 to 3000 model range, again you have to be careful about the similar 89W units)

rated at 67W vs the 89W you already have. You can get one for about $25.

They'll only save you a couple of watts at idle. I'm not sure if that is worth it.


Some low power current AMD cpus are

Athlon II X4 600e 0.775v - 1.2v 45W

Athlon II X3 400e 0.775v - ???v 45W

Athlon II X2 235e 0.775v - 1.35v 45W
Athlon II X2 240e 0.775v - 1.35v 45W

Athlon II X2 260u 0.85v - 1.15v 25 W

Considerably lower wattage but also considerably more expensive than just swapping a CPU.

My concern though is that your power draw isn't primarily from the CPU.

What video card, Power supply, hard drives are involved? Maybe there is another component that is better to swap out.

If you have a video card that is drawing lots of power going 785G takes care of the motherboard, CPU, ram, and video card with power savings on all (though the cost is noticably higher).

Another option assuming you have a PCIe slot might be to swap the current video card for an ATI 4350 or 5450 which both have very low power draw and would handle HTPC usage. Or is this a gaming PC?

[psiu]

Not sure what it's like in Europe but you can make some decent money here on something like ebay or tech forums selling the dual core 939 parts...might be better to sell off the stuff and get a more modern system.

Even the single core parts are pretty power hungry. Don't think you would get an equivalent amount of power savings for the performance decrease you would have (though you did mention you don't care about the performance).

I don't think I got much lower with a single core 939 system and graphics card (maybe into the 80W range?).

[sloeer]

Thanks for all your suggestions!

Some clarifications:
The plan for this computer is to use it as a headless server running samba, apache, sshd.... It will replace a undervolted 1.26GHz tualatin P3, which is fast enough, but lacks sata and usb2,i.e., I must stress the pci bus on the P3 with addoncards = bad throughput.

I wanted to use the old 939 system since performancewise, it is more than enough and, most importantly, its the cheapest way to replace the P3.
A new system (atom, 775 or am2+/am3) with m/b ,cpu and ram, would set me back atleast €120. In terms of features (amount of ram, pci-e, sata, usb2...), this would be equivalent to the 939 system.
A used A64 is about €10-15.

The 95W power draw was measured when booting a live linux cd. No hd, simple S3 pci graphics, 1 stick of DDR RAM, a cdrom, nothing else connected. I tried a few different psus but no major difference. In windows, with a hd connected, I get roughly the same reading.

As I keep reading that the athlon 64 with cn'c is drawing just a few W idle, maybe the asrock motherboard with the Uli 1695 chipset is the culprit?


edit:
I think you are right, I'm better off selling this crap.

Thanks