Re: lower power PCs

[ddl@danlan.*com (Dan Lanciani)]

In article <s7tv34direo53ip0ks9t16bmv0o1r6t8h1@xxxxxxx>, MFHult@xxxxxxxxxxxxxxxxxxxxx (Marc_F_Hult) writes:
| On 29 May 2008 06:42:55 GMT, ddl@danlan.*com (Dan Lanciani) wrote in message
| <1348312@xxxxxxxxxxxxxxxxxxx>:
|
| >For some time I've been using an old Dell Optiplex P3/600 for some home
| >control and A/V functions.  It is a big tower with a number of PCI and
| >ISA cards, three older hard drives, and a CDROM.  I was always pleased
| >that it lights no LEDs on the power scale of the 1000VA UPS to which it
| >is attached.
| >
| >I wanted a little more CPU power to allow for some MPEG transcoding so
| >I'm replacing the Optiplex with a more modern P4/3GHz machine with
| >two recent hard drives, a DVDR and an FX5200 video card.  (Everything
| >else is on the ASUS P4C motherboard.  This "new" machine is a few years
| >old, but much newer than the Dell.)
| >
| >I was a little disturbed that the "new" machine lit two LEDs on the
| >UPS, so I got out my genuine glass-cased watt-hour meter.  Turns out
| >that the old Dell draws about 60W while the new machine draws 140W.  Ok,
| >I realize the "new" machine is a lot faster but I thought efficiency
| >improvements had at least somewhat offset this.  Am I being unrealistic
| >or should I be able to do better?
|
| Dan,
|
| My Server 2003 machine uses essentially the same motherboard (ASUS P4C
| Deluxe) as yours with a 2.4ghz P4 CPU and five large drives. It idles at ~135
| watts so your experience is probably typical.
|
| P4's are power hogs. It was due in part the inexorable increase in power and
| attendant heat that Intel to moved to dual/multi-core CPUs instead of
| increasing P4 clock speeds beyond 3.8ghz. (I was fully expecting a
| celebratory 4.77ghz P4.)
|
| According to this:
| http://www.tomshardware.com/reviews/intel-cpu-power-consumption,1750.html

Yikes, is he talking about 100+W for just the CPU?

| the newest Intel Duo core CPU provide a "400% performance per watt increase"
| compared to P4's.

I wonder if that means I can have the same performance for 25% of the power.

| So yes, "efficiency improvements ha[ve] at least somewhat offset" power
| increases with the most recent CPUs, but not significantly with the CPUs we
| use - which are close to the worst of the bunch.

At this rate I could run two of the older P3 machines for less power than
the P4, and have lots more disks too.

| Note too that some new video cards consume more than 100 watts -- even more
| than the CPU in the system.

The FX5200 is by no means a super board; it was the lowest-end AGP card
I had handy.  But I might be able to find something even less featureful.

| You write "more cpu power to allow for MPEG transcoding" which would implies
| that this is done by the CPU and not in hardware on the video card.

Yes, the only reason for the video card is to provide console text message
display.  I don't need graphics at all.  In the old days I'd be using a
monochrome text adapter.

| Also: Check the power supply. There may be room for increased efficiency and
| improvement in power factor there too,  especially if your UPS is a full time
| conversion unit. The resulting five conversions each have less than 100%
| efficiency:  120AC--> 160DC-->120AC-->160DC--> 12vdc+5vdc+3.3vdc.

The UPS is an APC SmartUPS which switches.  I have been wondering if
improved power factor supplies (which don't do me any good since like
most residences I pay only for real power) could actually be less
efficient.  I can imagine that faced with a power factor mandate, a
price limitation, and no explicit efficiency mandate a designer could
come up with a less efficient design than one might like.

				Dan Lanciani
				ddl@danlan.*com