On Fri, 07 Oct 2005 18:51:03 GMT, "Phil Weldon"
wrote:
'Alfie [UK]' wrote, in part:
| The OP was advised it may be a problem with power supply because of the
| shutdowns. Most new graphics card need 1 or 2 direct power connections
| and this means a 300w PSU just won't cut it anymore.
_____

Most of that info came from my own experiences when I first put a nVidia
Geforce 6800 GPU (requiring 1 additional PSU connection) in my PC, it
would often power down for no reason whatsoever, and then trying to find
out why.

Your statement 'Most new graphics card need 1 or 2 direct power connections
and this means a 300w PSU just won't cut it anymore.' isn't necessarily
true; a 300 watt PSU may very will be completely adequate.

OK, I should have said MAY not cut it anymore. With the new GPUs
requiring their own power if you have multiple drives and USB devices
you MAY run out of power. The PSU will shut itself down in these
situations, pretty much any PSU has a built in fuse for too much power.

Your statement 'if you have a too high rated PSU and are not drawing a
significant power level the PSU can shutdown, act erratically, or blow it's
12v rails through 'overheating' is not at all true.

I stand by this statement, to some degree. I replaced my system with a
500w power system but it would also suffer power downs for no apparent
reason. I was advised that my system did not draw enough power and the
PSU was invoking power-over management and reducing power output to
avoid a 'burn'.

Your statement| 'You want at least 20% more power coming out of your PSU
than the calculator says you need to be safe from the typical fluctuations
you can get in a PSU, especially cheaper PSUs that might not have a stable
power profile.' makes no sense at all.

Hmm, yes, questionable. The calc suggested 310w used, so I put in a 350w
cheapo and when it got hot it would power down. Using the mobo power
check, when it was hot the PSU delivered less power, to the point it
would trip. I bought a more expensive 350w dual rail PSU and it was much
more stable.

Your statement 'Over 65% more power means you are at risk of damaging your
PSU through 'overheating' as it's generating a lot more power than you
need.' is ludicrous.

I was advised by others not to put in a 500w PSU as I first wanted to
do. Yes PSUs have under-draw protection, but prolonged use at low power
levels supposedly reduces the lifetime of the PSU.

As the 2nd link you provided states; PSUs MAY not have over-temperature
protection, where over-temperature is the result of current overload or
fan failure.

Try a read of
http://www.formfactors.org/developer...0Ratified.pdff
and
http://www.formfactors.org/developer...public_br2.pdf
.
Pay particular attention to:
"System power supply needs vary widely depending on factors such as the
application (that is, for desktop, workstation, or server), intended ambient
environment (temperature, line voltage), or motherboard power requirements."

--
Alfie
http://www.delphia.co.uk/
It's called Irony. You know. Like goldy or silvery, only it's made out of iron.