stiffman320 said:
Thanks for your guys' help on my other post. Especially the part about
being twice as likely to have problems. I already have one.
The 8800 says it requires 26amps on the 12V+ rail.
Where do I get a PSU like that? The couple that I did find were $200+
and had over 800W.
Do I really need that much power? Or does a 600W PSU with 19amps do
the job?
If it sounds to you like I have no clue about power supplies or amps,
it's because I don't
Working out the power supply size, is like being an accountant.
You have to add up all the little bits, to get the overall picture.
The estimates provided by the video card makers, tend to be on the
high side. So you can survive with less, but how much less depends on
your system.
For example, a Core2 Duo might draw 6 amps from the 12V rail. A
previous generation, high end Pentium 4 might draw 130W, which
is roughly 12A from the 12V rail, at 90% Vcore conversion efficiency.
So if the video card company thinks about the Pentium 4 case, while
you are using a Core2 Duo, then they include 6A too much right there.
If you are planning on overclocking the processor, then the Core2 Duo
will draw proportionally more power, so that too must be taken into
account. That was particularly serious, for people overclocking D 805
dual core processors, because you could draw close to 200W if severely
overclocking one of those. Multiply the 6A Core2 Duo number, by the
percentage overclock, as a rough estimate.
So it does require some attention to details, to get the right answer.
There is a big difference, between a person using one hard drive and
someone using a dozen hard drives.
Numbers for the 8800 family are here, near the bottom:
http://www.xbitlabs.com/articles/video/display/msi8800gts-640_6.html
When you can post the expected set of components you will be using,
then it may be possible to work out an estimate.
Post #9 here, is an estimate for a Core2 system with an 8800 family
card. Total current is estimated at 13.2A + 6A from the two 12V
rails. Post #12 is with a slight component change to the config.
http://groups.google.ca/group/alt.c..._frm/thread/97dcdddeeeffbdf1/e00425e36416dd39
So 20 amps total appears to be enough for a basic Core2 Duo system,
without provision for overclocking. I also like to see a little
margin, over and above the calculated number, so 19A doesn't sound
like enough. The split between rails can also be important, but it
sounds like your old supply is a single rail unit.
If you want more details, a make/model of the power supply, and
a URL to the product web page, would help. As would any details
of the hardware you plan to use.
HTH,
Paul
