Well I have my low power[ish] PC put together now, I had a couple of issues while assembling it.
1 - The Foxconn G31MG-S isn't available anywhere, it looks as if it won't become available for a few weeks yet. Since I want the computer now I have used a boring/generic/cheap Foxconn motherboard instead. As a result consumption is rather higher than predicted but is still quite acceptable at around 50 watts when idling with two disk drives and a CD/DVD drive. I could save a watt or two by unplugging the CD/DVD but it's hardly worth the effort.
2 - Some power supplies don't handle SATA drives well. I wasted a load of time on this. I ordered a case *and* a power supply when I ordered the parts for the system. The case (to my surprise) came with a 355 watt power supply so I though I might as well use that and keep the ordered (430 watt) one as a spare. I built the system and it worked OK until I added a second SATA drive, or at least I saw the same symptom a few times with only one SATA drive but put it down to misconfiguration. However when I tried to get it going with two drives it always just powered up for two or three seconds and then powered down again. A bit of searching suggested that it *might* be a power supply problem and so it was, using the 430 watt supply instead has made it work perfectly. Amazing that a system which idles at 50 watts and always uses less than 100 watts can't start up with a 355 watt power supply. Apparently SATA drives hit the 12 volt rail harder than IDE drives used to.
I'll probably buy a Foxconn G31MG-S when they become available, more for the fun of seeing how low power I can be than for any real saving. The difference of 20 watts will only save about 0.5KWh per day so the annual saving is only around £20.
2008/11/16 Chris G cl@isbd.net:
As a result consumption is rather higherthan predicted but is still quite acceptable at around 50 watts when idling with two disk drives and a CD/DVD drive. I could save a watt or two by unplugging the CD/DVD but it's hardly worth the effort.
Does the OS you use scale CPU frequency properly?
I recently tested a Dell Optiplex 755 with a discrete ATI video card 4GB of RAM DVD writer 2 HDs and a 2.8GHz Intel Quad core CPU at 50 watts, so for a simpler machine, I'd have hoped for rather less power use than that.
Hi
2008/11/16 Chris G cl@isbd.net:
came with a 355 watt power supply so I though I might as well use that and keep the ordered (430 watt) one as a spare. I built the system and it worked OK until I added a second SATA drive, or at least I saw the same symptom a few times with only one SATA drive but put it down to misconfiguration. However when I tried to get it going with two drives it always just powered up for two or three seconds and then powered down again. A bit of searching suggested that it *might* be a power supply problem and so it was, using the 430 watt supply instead has made it work perfectly. Amazing that a system which idles at 50 watts and always uses less than 100 watts can't start up with a 355 watt power supply. Apparently SATA drives hit the 12 volt rail harder than IDE drives used to.
Really? How? Why? I seem to remember reading that my Western Digital 500GB 7200rpm SATA drives use 6W each. And this AFAIK was from the datasheet/specs from WDC.
Is 6W really that much of a difference to cause this problem?
Surely it's probably due to a rubbish unbranded PSU with badly rated/cheap components? What make is it?
Srdjan
2008/11/16 Srdjan Todorovic todorovic.s@googlemail.com:
Hi
2008/11/16 Chris G cl@isbd.net:
Amazing that a system which idles at 50 watts and always uses less than 100 watts can't start up with a 355 watt power supply. Apparently SATA drives hit the 12 volt rail harder than IDE drives used to.
Really? How? Why? I seem to remember reading that my Western Digital 500GB 7200rpm SATA drives use 6W each. And this AFAIK was from the datasheet/specs from WDC.
Correction. 9.5W
Mode 12 V 5 V Power Read/Write 450 mA 800 mA 9.5 W
Is 6W really that much of a difference to cause this problem?
Surely it's probably due to a rubbish unbranded PSU with badly rated/cheap components? What make is it?
I seem to remember reading/being told (before I bought my PSU) that the generic PSUs one gets free with cases usually are quite rubbish, not stable and generally can't provide enough current on the power rails. Perhaps this is the problem?
Srdjan
On Sun, Nov 16, 2008 at 04:34:28PM +0000, Srdjan Todorovic wrote:
Hi
2008/11/16 Chris G cl@isbd.net:
came with a 355 watt power supply so I though I might as well use that and keep the ordered (430 watt) one as a spare. I built the system and it worked OK until I added a second SATA drive, or at least I saw the same symptom a few times with only one SATA drive but put it down to misconfiguration. However when I tried to get it going with two drives it always just powered up for two or three seconds and then powered down again. A bit of searching suggested that it *might* be a power supply problem and so it was, using the 430 watt supply instead has made it work perfectly. Amazing that a system which idles at 50 watts and always uses less than 100 watts can't start up with a 355 watt power supply. Apparently SATA drives hit the 12 volt rail harder than IDE drives used to.
Really? How? Why? I seem to remember reading that my Western Digital 500GB 7200rpm SATA drives use 6W each. And this AFAIK was from the datasheet/specs from WDC.
That's what I'd have though too but it was fine with two IDE drives and a SATA drive, it was just two SATA drives together that caused problems.
Is 6W really that much of a difference to cause this problem?
I think it's the startup current rather than the steady state.
Surely it's probably due to a rubbish unbranded PSU with badly rated/cheap components? What make is it?
If you hunt around using Google you come across quite a few people who have had problems with multiple SATA drive and various branded and other power supplies.
Yes, it was a 'generic' cheap power supply but it was the SATA drives that tipped it over the edge. The one that worked cost less than £10, hardly 'top notch'!
On Sun, 2008-11-16 at 17:35 +0000, Chris G wrote:
Yes, it was a 'generic' cheap power supply but it was the SATA drives that tipped it over the edge. The one that worked cost less than £10, hardly 'top notch'!
Any idea what the efficiency rating is on that ? The cheapest PSU's can drop as low as 60% or so (depending on load...SMPSU's don't have a linear efficiency curve so a single figure here can be meaningless)
Personally I never use PSU's quite that cheap in any machine I care about mostly because they tend to lack any overvolt clamping on the output.
This has been from past experience at a previous job where we had some very expensive artist workstations that had been built with cheap PSU's. Several failed taking every single major component of the machine (even the keyboard in one case) and on machines where the GFX card was £1800 and we had a 1GB of ram at a time when ram was £2/MB that wasn't very funny.
OK so your machine isn't as expensive as that but too many machines with cheap PSU's have passed through our workshops where the PSU has taken a Hard drive or Mainboard with it..I have yet to see this on recognised quality makes such as Antec/Coolermaster/Enermax/Seasonic etc...Ebuyer do an Arctic Power series of PSU's I have been very happy with at reasonable prices and I think they may publish some efficiency figures.
I forgot to add, PSU's made by companies that care about efficiency will have an 80plus logo which means they have been tested and certified to have at least 80% efficiency at 20 50 and 100% loads.
However please note that it is not clear whether they do these tests for 220/230v as well as 110v so although the list of PSU's is relevant the figures might not be accurate for use in the UK.
See the current list here http://80plus.org/manu/psu/psu_join.aspx
On 16 Nov 2008, at 16:15, Chris G wrote:
Well I have my low power[ish] PC put together now, I had a couple of issues while assembling it.
<snipola>
By a strange quirk of fate, I was looking for a low power system, and have ended up ordering one of these:
http://www.trustedgoods.com/product_p/nslu2.htm
Mix it with this:
and a USB drive or two of your choice (I ended up with some Western Digital wotsit) and I'm hoping I should have a cheap linux server. If it turns out to be beyond me I can just use the drive & NSLU2 as a NAS, or for holding up the tank on the K100RS while I fix the chuffin' fule pump connector again.
Errr, sorry. Completely missed the start of this thread, so I have no idea if the NSLU2 has been mentioned previously. Even so, if anyone wants one, the price on the site above is worth taking note of.
nr.
On Sun, Nov 16, 2008 at 09:59:12PM +0000, Neil Ronketti wrote:
On 16 Nov 2008, at 16:15, Chris G wrote:
Well I have my low power[ish] PC put together now, I had a couple of issues while assembling it.
<snipola>
By a strange quirk of fate, I was looking for a low power system, and have ended up ordering one of these:
http://www.trustedgoods.com/product_p/nslu2.htm
Mix it with this:
and a USB drive or two of your choice (I ended up with some Western Digital wotsit) and I'm hoping I should have a cheap linux server. If it turns out to be beyond me I can just use the drive & NSLU2 as a NAS, or for holding up the tank on the K100RS while I fix the chuffin' fule pump connector again.
I have a USB drive which, it turns out, consumes 20 watts all by itself. It's a Freecom 500Gb drive. So that rather spoils the idea of a low power system if you add two of them!
Errr, sorry. Completely missed the start of this thread, so I have no idea if the NSLU2 has been mentioned previously. Even so, if anyone wants one, the price on the site above is worth taking note of.
A d-i-y NAS was one approach I tried but it ended up not really being quite what I wanted and I decided an efficient (or reasonably so) 'normal' system would work better for me.
On Sun, 16 Nov 2008 21:59:12 +0000 Neil Ronketti neil@ronketti.org allegedly wrote:
By a strange quirk of fate, I was looking for a low power system, and have ended up ordering one of these:
http://www.trustedgoods.com/product_p/nslu2.htm
Mix it with this:
and a USB drive or two of your choice (I ended up with some Western Digital wotsit) and I'm hoping I should have a cheap linux server. If it turns out to be beyond me I can just use the drive & NSLU2 as a NAS, or for holding up the tank on the K100RS while I fix the chuffin' fule pump connector again.
That's a good price. The NSLU2 has been EOL'd by Cisco and they are apearing on ebay at more than that.
I have two, both running Debian Lenny with 500 Gig disks attached and can vouch for their usability (and silence). Just don't expect them to run database driven web servers...
Mick
---------------------------------------------------------------------
The text file for RFC 854 contains exactly 854 lines. Do you think there is any cosmic significance in this?
Douglas E Comer - Internetworking with TCP/IP Volume 1
http://www.ietf.org/rfc/rfc854.txt ---------------------------------------------------------------------
-
Chris G -
mbm -
Neil Ronketti -
Ric Davis -
Srdjan Todorovic -
Wayne Stallwood