If you see in my other replies I'm going to try some simpler things first,
but thanks for the tutorial and the link.
: In article <
[email protected]>, "Clif" <
[email protected]>
wrote:
:
: > In my bios the fan speed has started showing in red when it goes below
: > 1800rpm. I am also occasionally getting artifacts on the screen just
running
: > WinXP, no games. I've got a fully loaded system. 3 DVD writers, 6 hard
: > drives, quite a few case fans and a, recently added, XFX geforce 6800 GT
: > video card. I thought this power supply would do the trick being a good
: > brand. Do you think I need to go to 500 and something power supplies?
and is
: > the fan speed in the bios telling me the supply is over taxed or that
it's
: > going bad?
:
: The first thing to do, is check the power supply voltages,
: either using the hardware monitor in the BIOS, or when you
: are booted into Windows, install and use Asus Probe to
: measure the voltages. ATX supplies are supposed to regulate to
: within 5%, and should do better than that normally. By
: checking the voltages, you'll get a good idea as to whether
: it is the power supply, or perhaps the video card is flaky.
:
: When it comes to selecting a power supply, the total watts is
: not the only parameter to use. The reason this is the case,
: is because some supplies put all their effort into the +5V
: rail, leaving a pathetically inadequate output level on the
: +12V rail. Some of the old Powmax 500W supplies, had 12V@10A
: and even though the supply was "500W", that supply could not
: run even a stripped down P4 system.
:
: You really need a calculator that works out the current
: required for each rail. The heavily loaded rails are
: +3.3V, +5.0V, and +12V. The other rails, -5V and -12V are
: used for tiny currents or not at all. The +5VSB is used to
: power the sleeping computer, keep the contents of RAM, and
: power parts of chips used for "wakeup" functions like
: Wake On LAN.
:
: This site contains a calculator. It attempts to work out the
: current required for each of the heavily loaded rails. Unlike
: other sites, it has more realistic number for RAM current (a
: DDR DIMM is closer to 5 watts, rather than the overestimates
: on other sites).
:
:
http://takaman.jp/D/?english
:
: What these calculators cannot do, is get the balance exactly
: right on all three rails. Most modern motherboards now use
: the ATX12V 2x2 connector to power the processor, and the
: calculation of the +12V requirement will be the most accurate
: of the three. The currents required of +3.3V and +5V are
: generally small enough, that once you've bought a power supply
: that meets the +12V requirement, there is enough current for
: the other rails. (In the table below, all the supplies listed
: have plenty of +3.3 and +5V.)
:
: If your motherboard doesn't use the ATX12V connector, then some
: fiddling of the calculated numbers will be needed to gauge the
: power supply. (For example, my A7N8X-E draws heavily from the
: +5V supply, and with a good video card, somewhere between 20 and
: 25A are needed. The motherboard draws very little +12V, and the
: disk drives draw most of the small amount of +12V needed.)
:
: So, armed with your calculated +3.3V, +5V, and +12V current
: requirements, you can go shopping. Good brands will specify
: the current available on each rail, and each brand has
: different characteristics (either just barely skimping by,
: or having more total output than the wattage rating would
: suggest). If a cheap power supply just lists the total wattage,
: and provides no details, look for another brand that does give
: the necessary information. Here is a typical table from a
: reputable brand of supply.
:
: VOLTAGE +5V +12V +3.3V -5V -12V +5VSB
: TRUE330 30A 17A 28A 0.5A 1.0A 2.0A
: TRUE380 35A 18A 28A 0.5A 1.0A 2.0A <--- $65 US
: TRUE430 36A 20A 28A 0.5A 1.0A 2.0A
: TRUE480 38A 22A 30A 1.5A 1.0A 2.0A
: TRUE550 40A 24A 32A 0.5A 1.0A 2.0A <--- $95 US
:
: HTH,
: Paul
) .