> Thanks veyr much for this info. Some addl. questions. What is the
> exact wattage used by a 2ghz 478 128kb l2 cache celeron? 2.4ghz same?
You'd have to check with Intel's website - it will list two figures, the practical
design thermal wattage and the theoretical thermal output (which doesn't apply).
> Would a high end video card really consume 55W? I thought the PCI
> spec max was around 20W or so?
Yes they can - they will eventually go beyond 75W since they are
outpacing CPU on transistor count & have a lot of hot running RAM.
They use a separate power-connector on some as I recall, I think the
hottest graphics card is over 130W - but that uses a separate feed, is
for a specialist application and is several thousand dollars (>4,000$US).
> What about the motherboard in general? I see your data for HD and
> RAM, but the motherboard has the bridges, and the extensive i/o (on
> board lan, fdd, hdd, usb, etc. etc.).
I've included it in the graphics card effectively, it's quite small. All that
I/O is only about 5-8W, onboard graphics are 10-25W, and then you
go beyond that figure when you hit the very hot graphics cards.
A typical PC will draw about 170W at typical usage, less at idle.
That's up from 85W a few years back, low-power PCs about 110W.
Remember big servers have 500-680W PSUs because they often have
4-7-14 very hot high-speed 15.3k-rpm SCSI drives - *each* >25W,
plus twin RAID cards which have hot CPUs, plus lots of RAM.
As I posted in reply to someone today...
It comes down to the spec of the PC:
o Mini-ITX P4 PC + 7200rpm 3.5" + onboard graphics
---- use Mini-ITX DC-to-DC convertor board & laptop PSU brick
---- that is available in 120W - yes, a P4 run off a 120W laptop PSU
o Mini-ITX P4 PC + 7200rpm 3.5" + top-end graphics
---- use the 143-170W laptop-brick & convertor board
o P4 with 7x 15.3k-rpm SCSI drives, RAID controller
---- obviously you need another 250W for the HD
---- so here is where the 450-550W PSUs come in
So it comes down to application.
The reason people went to bigger PSUs was because the
low-wattage ones were basically noisy &/or low-quality.
Conversely, FSP-Group/Sparkle/SPI (all same company) do
a perfectly good 250W & 350W ATX PSU. Others do ok
150-250-300W 1U PSU for smaller form factors, and the
Shuttle still has a 150-250W PSU for top-end P4 systems.
Low quality PSUs can't cope with even suppling 80% of rated
load continually 24/7, whereas quality ones can handle 100%.
So people went for higher wattage for safety, when in reality
a properly engineered smaller PSU would do quite perfectly.
Antec, Sparkle & others are good quality PSUs - another is
PC-Power-&-Cooling but they & Antec just spec a PSU that
is made for them, and just spec a higher level than cheap-end.
A EPIA and /just about/ a Cel-1.2 Tualatin (32W) can be run
on a 60W Morex laptop brick PSU & DC-to-DC convertor.
You'd probably need low-end integrated graphics (old skt 370),
and obviously use a 2.5" disk - but it's possible to squeeze it in.
--
Dorothy Bradbury
www.stores.ebay.co.uk/panaflofan for fans, books & other items
http://homepage.ntlworld.com/dorothy...ry/panaflo.htm (Direct)