Archived from groups: comp.sys.ibm.pc.hardware.chips,comp.sys.intel (
More info?)
> I've built a few dual-Opteron workstations and a good
> 550 or 600 W PSU is plenty for a pair of Opty 250's,
> a high-end workstation or gaming graphics card, 8 GB
> of RAM, a DVD burner, and four SATA hard drives,
> plus a few other little things like video capture cards,
> sound cards, etc.
Indeed, the article cites later some "small print" caveats:
o Figs are short-duration peak - beginning to sound like PMPO
o Figs are unremarkable 18A on 12V rail - rail grouping limits
Will be interesting to verify ATX compatibility re protection.
Price wise at 400$+ it better have had no corners cut in there.
Would be better if they spent the $ on better components:
o Stick 105oC or 125oC Mil-Spec electrolytics in there
o Most common failure in SMPS, and would cost << 400$
A more realistic industry maximum figure is 670W:
o Dual-Core Dual-CPU + 15.3k-rpm SCSI RAID + DDR2-667 1GB Dimms
---- multi-GB of memory gets very hungry re 10W/Dimm
o Dual-Core Dual-CPU + Very high-end Graphics-Card
In high-end servers you're more interested in N+1 than having
one super-big single-point-of-failure (ok, Gov't IT buyers aside).
Tend to see 950-1150W only in triplicate on multi-blade servers.
The multi-CPU/PCI backplane crowd are more interested in using
multiple ATX PSUs for Cost + Redundancy into a smart backplane.
Potentially you can hit a catch-22 of oversized PSUs re efficiency:
o SMPS tend to get more efficient as power drawn rises
o A very high output PSU is often somewhat inefficient at low load
---- efficiency can be 60% at the low end, 75-80% at the high end
o That low load may not be at the tail end of usage distribution
o On the contrary, it might actually be commonly encountered
---- the average PC draws around ~85W
Longer term P-M architecture will assist thermal dissipation.
o I wish AMD would push 25W Mobile Athlon on Desktop harder
o Mobile Athlon are pretty cheap, and use a cheap desktop board
---- a caveat is 25W Mobile Athlon seem rare (re P-M 21-28W)
---- even so £80+45 isn't too difficult to get something usable
---- cheaper than a Commell Skt370 VIA PL133 Tualatin + CPU
o P-M cpu are pricey, and use expensive proprietary boards
---- £160+189 is pretty steep, altho the board takes a 12V supply
---- easy to find fanless to 50oC DIN-rail single-rail PSUs
If poor low-70% efficiency for a 950W PSU, it's pulling 1350W:
o Ok, that is only be drawn if it were at 100% load
---- which is indicated to be short-term only
o Even so it would be 400W dissipated within the PSU
---- even under ideal conditions that needs 80cfm
Globally industry/regs/gov't have ensured few power plants built.
Economically it wasn't worth building them - until now, and thus
the easily manipulated upwards electricity pricing market. It is not
impossible to design SMPS of 85-90% efficiency, saves money.
Ok, it's not wasted money if you do want the room warming.
Perhaps Enron should have gone into PSUs & CPUs...
--
Dorothy Bradbury
pPP
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