Hi all,

I have just done an investigation in the house to work out why my electricity bills are so high and one of the main offenders is my dual xeon server which idles at 200W..

This server runs VMware and in the past ran 6 virtual servers but now its only running 2 and these are idle nearly all the time..

I am looking to use some parts I have to build up another system that will hopefully draw far less power..

I have a C2D E4400 processor kicking around, some memory and and antec case with PSU.. I will also only be running two hard drives in the new system..

Now for the questions..

Is an E4400 worth using to make a low power server?
My thinking is that I have it already so might as well use it but if its power hungry I might look at something else..

How do you determine which motherboards have lowest power consumption?

Does memory speed affect power usage? In other words will 533Mhz memory use less power than 800mhz and is it a significant difference?

How do I find out which motherboards support VT? (in case I need it later and then I can just change the proc because the E4400 doesn't support it)

Is a target of 50w idle reasonable?

VT-x is on the processor side and most motherboards have it enabled. VT-d is on the chipset/motherboard (at least for Core 2), but that would likely require you to get a workstation or server class board. Sometimes, even if the chipset supports VT-d, it's not enabled in consumer class motherboards. For the most part, VT-x is all you'll need.

Yes, 50W idle is doable with 2x 3.5" drives (green ones preferred). I think a G31 motherboard + Celeron E3x00 or Pentium E5300 (SLGTL) would fit your low idle power requirement quite nicely.

As a point of comparison:


Add around ~5W for each 3.5" drive at idle and you're still below the 50W requirement. Another factor is the power supply. While I did mention efficiency was unknown for the PSU that came with the case, I'm pretty sure I'm getting fairly decent efficiency in the above build. Since you're targetting 50W idle, skip high wattage PSU's (the extremely efficient Seasonic X-650 being the exception). Ideally, you'd likely want to use a 250W 80Plus PSU. If you already have one on hand, though, just use what you have. Going from 200W to 50W is a fairly significant reduction (~$10/mo at $0.10/kWh) and if you can recoup costs by selling your current parts, then all the better. Quibbling about an extra 10W or so, not really...

By the way, I'm pretty sure the E4400 Allendale is pretty power-efficient already (the M0 stepping, at least). I reckon you wouldn't see drastic power reduction by going from Allendale to low-end Wolfdale. However, the latest crop of Wolfdales also offer VT-x support which is lacking in the E4400.

Thanks for the comprehensive reply.. Think I will look into the VT side but if I don't have it its no train smash..

Just an update..

I built the new box..
Specs
E4400 cpu
Asus P5KPL-AM EPU motherboard
4GB RAM
2x 500GB Seagate 7200rpm SATA drives

Idle is now 58W (compared to old server at 200w) and I would imagine a lower power more efficient PSU could take a bit more off that since I am using the Antec PSU that came with the case (I think its a 320w or 350w).. Don't seem to be many low power ATX PSU's around..

Have two 12mm fans spinning at about 700rpm.. The loudest part of the whole build is the hard drives but the hum from the UPS is louder so not worried about it..