Re: Advice on replacement power supply

Dr.H@l0nf1r£$ wrote:
Daniel James wrote:
In article news:<qJ-dnbq05q6YGVHbRVnyjwA@xxxxxx>, Dr.H@l0nf1r£$
wrote:
Incidentally I'm no too sure on this; I have [snip spec] ...

What a strange configuration! Onboard graphics (so not a gaming
machine, then) but lasers and light-up fans!

I would get rid of the silly lights. They don't use much power, but
100% of it is wasted.

The light-up bits were 2nd-hand off-the-shelf bits that I added for
the sake of adding...

So, modest CPU, motherboard, onbard graphics (what chipset?),

NVIDIA GeForce 6100 nForce 405

2
HDDS, 2 DVDs, cardreader, KB, mouse and KVM (powered by the system
unit?), fans & stuff ... how much RAM (in how many sticks)?

1x1GB and 1x256MB

So, by very rough rule-of-thumb:

modest CPU say 30W (might be a bit more)
Basic mobo say 25W (the graphics might add to that)
RAM say 5W a stick (I'm assuming 2).
Case/fans etc say 10W (wild guess)
HDDs say 10W in use, 30W during spin-up (each)
opticals up to 35W in use, maybe 10W when idle (each)
KB, mouse, KVM -- no idea. say 10W the lot?

That comes to 225W if everything draws its maximum at the same time,
which it won't but you have to allow for the worst case. ... Oh,
plus (say) 10W for the RAID card (wild guess).

I haven't allowed anything for your glow-in-the-dark crap, but it'll
only be 5-10W.

If you add two more hard drives you'll add about another 60W to that
for spin-up, which will take you over your PSU's 250W for a few
seconds at startup. A *GOOD* 250W PSU might take that in its stride,
an average one might cut out, a cheap one will blow up, a cheap and
nasty one will blow up and take half the system with it. . You can
probably bring it all within 250W if you stagger the drive spin-up
times so they don't all start to draw 30W at once ... but it's all a
bit marginal and a more powerful PSU would be advisable.

If you'll pardon my saying so ... you're the one with the PC-making
business ... you really ought to /know/ this stuff. It doesn't
inspire one with confidence to see you asking such basic questions
here.


Yes I see what you mean. I always allow a large excess in any machine
that I build in order that the PSU never reaches its rating. (I also
work mainly with rough estimates except in the default machine's
pre-published technical specifications which I worked out
previously.) In this case however, it being my machine yet one that I
didn't initially build, we're talking marginal figures and I'm
looking to get the opinions of others to put alongside my own on how
much I can get away with without changing the PSU. : Having a
nackered fan plus the margins being so close has made up my mind to
discard the old 250W and fit the 350W PSU at the same time as
installing the RAID configured HDDs. - It's not so much a case of
having no idea as a case of having a rough idea but also seeking the
opinions of others - which doesn't hurt anyone to do. Also not
everybody can know everything there is to know about anything, so
shared knowledge is a plus and may bring up matters that weren't
initially considered in the primary analysis. Having studied
electronics for years as well as being a fully qualified electronics
technician I'm obviously fully schooled in Ohm's Law etc; but once
again asking the opinions of others is always a good thing in
addition to my own opinions. (: Also I'm too lazy to check every
component of the PC in question and do all the calculations if the
truth be known. plus I don't have the time ATM. )

So then the conclusion is that the risk is too great bearing in mind
the duff fan, and the load - which I thought may be excessive, which
is why I sought other opinions.


Google for [PC power consumption] and you'll find various pages that
talk about this, some will calculate it for you.

It would be very useful if either the amperage or the wattage or both
were stamped on the component's label; but in most cases this is not
done it appears

Also is it possible to get an Athlon 64 x2 in a socket 754? I can't
seem to find one anywhere.

I don't recall ever seeing a dual-core CPU for S754. They exist(ed)
for S939 but even those are scarce, now.

I thought as much.

Thanks for your input Daniel; much appreciated.

So there I was, my evening out having been cancelled due to most of the
other girls being unavailable for whatever reason, and I was thinking what a
good idea it would be to use the spare time to change the PSU, - when a loud
buzz preceeds a hiss and grey acrid smoke. - And death - At least that
solved the problem of what to do with the Sempron computer. RAM and
motherboard appear fine, PSU has cooked and taken out at least 1 of the
HDDs.


.

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