Athlon64 3500, Geforce 6800ultra - Which power supply?

  • Thread starter Thread starter Marc Brown
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Marc Brown

Subject says it all. I hadn't really planned on buying a new power
supply (I currently own a 420W semi-generic), but when I think
about the 6800 Ultra's original recommended wattage, plus the fact
that I'll be trying to overclock the Ultra, ram and cpu, I begin
to suspect that I may need something more. This may be incorrect.
Feel free to enlighten.

Assuming I do need something more, what should I get? It looks like
a regular, non-elite 480W can be had for $75 or less. Or for as
much as $150. A lot of variety with power supplies, most of which
I suspect is the manufacturers taking advantage of pricing
ambiguity. I can, for example, understand why a 6800 Ultra costs
25% more than a 6800 GT, but the advantages provided by one power
supply which costs 100% more than an alternative are totally
unknown to me. I don't need the ultimate power supply.. that I
know of, anyway. Who knows? Maybe it really is a good idea for
some reason. Again, enlightenment would be appreciated.

And would 480W be enough, or would there be a risk of me taxing
even that?

Thanks as always.
 
Assuming I do need something more, what should I get? It looks like
a regular, non-elite 480W can be had for $75 or less. Or for as
much as $150. A lot of variety with power supplies, most of which
I suspect is the manufacturers taking advantage of pricing
ambiguity. I can, for example, understand why a 6800 Ultra costs
25% more than a 6800 GT, but the advantages provided by one power
supply which costs 100% more than an alternative are totally
unknown to me. I don't need the ultimate power supply.. that I
know of, anyway. Who knows? Maybe it really is a good idea for
some reason. Again, enlightenment would be appreciated.

And would 480W be enough, or would there be a risk of me taxing
even that?
Click to expand...
I'm not going to argue the advantages, if any, of an expensive PSU, but
hell would have to freeze over before I paid more than $25 for a PSU. My
current 600W was $24. My old 400W wouldn't even keep the system from
crashing after less than a minute. I bought 3 new PSU's, 500W ($12), 550W
($15), and the 600W ($24). All 3 ran my A64 3000+ system fine. So if you
have to buy a new PSU, I wouldn't get less than 500W in a cheap PSU. Oh,
the 500W and 600W are Lead Power, and the 550W is a Power Magic.
 
Let me just say (without knowing the rest of your system specifics, that
there is a hugh difference between various power supplies. Quality of
components used, cooling, and most importantly, the real power output as
temps begin to rise. For that reason, and because I run multiple hard
drives and optical drives on a completely overclocked system, I use PC Power
and Cooling. I also run my second rig with a Antec 550. Then again, you
may be ok with what you have.
 
Subject says it all. I hadn't really planned on buying a new power
supply (I currently own a 420W semi-generic), but when I think
about the 6800 Ultra's original recommended wattage, plus the fact
that I'll be trying to overclock the Ultra, ram and cpu, I begin
to suspect that I may need something more. This may be incorrect.
Feel free to enlighten.

Assuming I do need something more, what should I get? It looks like
a regular, non-elite 480W can be had for $75 or less. Or for as
much as $150. A lot of variety with power supplies, most of which
I suspect is the manufacturers taking advantage of pricing
ambiguity. I can, for example, understand why a 6800 Ultra costs
25% more than a 6800 GT, but the advantages provided by one power
supply which costs 100% more than an alternative are totally
unknown to me. I don't need the ultimate power supply.. that I
know of, anyway. Who knows? Maybe it really is a good idea for
some reason. Again, enlightenment would be appreciated.

And would 480W be enough, or would there be a risk of me taxing
even that?

Thanks as always.
Click to expand...

Stick with name-brands having over 18A of 12V capacity.
Thermaltake, Antec, Sparkle/Fortron, Delta, PC Power &
Cooling are good choices (from good to better in that
order). 480W from a PSU with accurate rating is enough,
providing you're not running a ton of hard drives too.

Don't know exactly what you mean by "regualar, non-elite",
but generally a good 480W PSU will cost in the neighborhood
of $65 (shopping around, on sale) or more commonly $75 & up.
Considering how much the rest of the parts cost, $100 is a
reasonable target.
 
Marc said:
Subject says it all. I hadn't really planned on buying a new power
supply (I currently own a 420W semi-generic), but when I think
about the 6800 Ultra's original recommended wattage, plus the fact
that I'll be trying to overclock the Ultra, ram and cpu, I begin
to suspect that I may need something more. This may be incorrect.
Feel free to enlighten.

Assuming I do need something more, what should I get? It looks like
a regular, non-elite 480W can be had for $75 or less. Or for as
much as $150. A lot of variety with power supplies, most of which
I suspect is the manufacturers taking advantage of pricing
ambiguity. I can, for example, understand why a 6800 Ultra costs
25% more than a 6800 GT, but the advantages provided by one power
supply which costs 100% more than an alternative are totally
unknown to me. I don't need the ultimate power supply.. that I
know of, anyway. Who knows? Maybe it really is a good idea for
some reason. Again, enlightenment would be appreciated.

And would 480W be enough, or would there be a risk of me taxing
even that?
Click to expand...

If you want a quality psu that will last... pc power and cooling all the
way.
 
When it comes to power supplies, higher quality units really are worth the
extra cost -- there really is a performance difference. I'd think that a
high quality 420 would probably be enough for you, and that a high quality
480 would give you some headroom. I'd guess that anything above this would
be overkill, even if you were using multiple drives. A high quality (like
an antec) 480 or even a 420 would be better than a low quality 550.

My advice would be to get something like an Antec TruePower 480.

Larry
 
" A lot of variety with power supplies, most of which I suspect is the
manufacturers taking advantage of pricing ambiguity. I can, for example,
understand why a 6800 Ultra costs 25% more than a 6800 GT, but the
advantages provided by one power supply which costs 100% more than an
alternative are totally unknown to me. "


Read the introduction of this Antec TruePower 550W review.
http://www.mikhailtech.com/modules.php?name=Articles&rop=showcontent&id=21
 
Marc Brown said:
Subject says it all. I hadn't really planned on buying a new power
supply (I currently own a 420W semi-generic), but when I think
about the 6800 Ultra's original recommended wattage, plus the fact
that I'll be trying to overclock the Ultra, ram and cpu, I begin
to suspect that I may need something more. This may be incorrect.
Feel free to enlighten.

Assuming I do need something more, what should I get? It looks like
a regular, non-elite 480W can be had for $75 or less. Or for as
much as $150. A lot of variety with power supplies, most of which
I suspect is the manufacturers taking advantage of pricing
ambiguity. I can, for example, understand why a 6800 Ultra costs
25% more than a 6800 GT, but the advantages provided by one power
supply which costs 100% more than an alternative are totally
unknown to me. I don't need the ultimate power supply.. that I
know of, anyway. Who knows? Maybe it really is a good idea for
some reason. Again, enlightenment would be appreciated.

And would 480W be enough, or would there be a risk of me taxing
even that?

Thanks as always.
Click to expand...

PSU is one of important component in a PC. Not everyone think of PSU when
purchasing or place on top of the list.
Depending on that individual, PSU is the main component supply power to all
components inside your PC. Quality PSU will help your PC run cleaner and
longer which depend on how it use and it environment that it use at. You can
get away with a with cheap PSU and might last forever. But getting a good
known manufacturer like Antec or Enermax etc. You can safely know it will it
a good quality PSU. Using cheap PSU is like a gamble / risk. Having a good
quaility PSU will prolong your components.

Again, it really depend on that individual and what to use for and the value
it apply to.

CapFusion,...
 
Marc said:
Subject says it all. I hadn't really planned on buying a new power
supply (I currently own a 420W semi-generic), but when I think
about the 6800 Ultra's original recommended wattage, plus the fact
that I'll be trying to overclock the Ultra, ram and cpu, I begin
to suspect that I may need something more. This may be incorrect.
Feel free to enlighten.
Click to expand...

6800 Ultra power usage report:
http://www.xbitlabs.com/articles/video/display/ati-vs-nv-power_2.html
Table of power usage at
http://www.xbitlabs.com/images/video/ati-vs-nv-power/6800u_table-b.gif

So right off the bat, it's going to be eating ~55W off the 12V line, and
~23W off the 5V line. Add in the CPU at 90W, thrown in the regulator
efficiency at ~80% to get ~115W, and you're already up to at least 14A on
the 12V and 5A on the 5V line. Hard drives, once spun up (they'll only spin
up when your GPU isn't working), consume about 0.5A off the 12V and ~1A on
the 5V. Add in the motherboard (southbridge and other chips have to be
powered), case fans (small usage off the 12V, ~0.2A for a normal fan), usb
devices, etc etc and you can easily get to 18A from the 12V under gaming
conditions. So the minimum you should be looking for is 20A on the 12V,
though I'd feel much safer with 23A or so. As long as the 5V line can supply
20A or so you should be fine, as not too much stuff uses 5V nowadays.

[...]
 
Thanks for those links. Does anyone know of a site showing similar power
consumption information for a GF4 Ti4600 at full load? I'm curious about
how much more power the 6800GT draws compared to a GF4 Ti4600.

Thanks,

Larry

Michael Brown said:
Marc said:
Subject says it all. I hadn't really planned on buying a new power
supply (I currently own a 420W semi-generic), but when I think
about the 6800 Ultra's original recommended wattage, plus the fact
that I'll be trying to overclock the Ultra, ram and cpu, I begin
to suspect that I may need something more. This may be incorrect.
Feel free to enlighten.
Click to expand...

6800 Ultra power usage report:
http://www.xbitlabs.com/articles/video/display/ati-vs-nv-power_2.html
Table of power usage at
http://www.xbitlabs.com/images/video/ati-vs-nv-power/6800u_table-b.gif

So right off the bat, it's going to be eating ~55W off the 12V line, and
~23W off the 5V line. Add in the CPU at 90W, thrown in the regulator
efficiency at ~80% to get ~115W, and you're already up to at least 14A on
the 12V and 5A on the 5V line. Hard drives, once spun up (they'll only spin
up when your GPU isn't working), consume about 0.5A off the 12V and ~1A on
the 5V. Add in the motherboard (southbridge and other chips have to be
powered), case fans (small usage off the 12V, ~0.2A for a normal fan), usb
devices, etc etc and you can easily get to 18A from the 12V under gaming
conditions. So the minimum you should be looking for is 20A on the 12V,
though I'd feel much safer with 23A or so. As long as the 5V line can supply
20A or so you should be fine, as not too much stuff uses 5V nowadays.

[...]
Click to expand...
 
Aside from the issues of cheap power supplies putting out too little
power for the needed voltages or of putting out "dirty" power, many
cheap power supplies tend to be quite noisy. It doesn't make sense
to suffer with a noisy pc when for a relatively small additional amount,
one can have a quiet one.

http://www.quietpcusa.com/
 
PSU is one of important component in a PC. Not everyone think of PSU when
purchasing or place on top of the list.
Click to expand...

Yep, I used to buy the cheap PSUs and caused a bit of
self-inflicted suffering (RAID sets that would
mysteriously fail and have to resync, reboots and other
strange behavior).

Buy a good quality power-supply, and you'll still be
using it 5 years from now. I think I usually pay about
$80 for a good P/S (480W), which is a good bit cheaper
then replacing failed components down the road.
 
Michael Brown said:
So the minimum you should be looking for is 20A on the 12V,
though I'd feel much safer with 23A or so. As long as the 5V line can supply
20A or so you should be fine, as not too much stuff uses 5V nowadays.
Click to expand...

Thanks for the many helpful replies, folks. I settled upon the
Antec True550. There seems to be a fair chance this will prove
adequate.
 
I'm not going to argue the advantages, if any, of an expensive PSU, but
hell would have to freeze over before I paid more than $25 for a PSU.
Click to expand...

I agree that most brand-name PSUs are overpriced, but having seen a
cheap no-name PSU burn out, taking a motherboard, hard drive, and CD-ROM
drive with it, I no longer trust my systems to $10 PSUs. At the very
least, I'd make sure to get something with overvoltage protection.

Also, read the fine print. One cheap "500W" power supply I bought
computes its wattage rating by adding the total wattage for each rail,
assuming that all the other rails are unloaded. This is a next to
useless measure for a real PC. The actual maximum power rating for the
unit is only 282W.
 
I agree that most brand-name PSUs are overpriced, but having seen a
cheap no-name PSU burn out, taking a motherboard, hard drive, and CD-ROM
drive with it, I no longer trust my systems to $10 PSUs. At the very
least, I'd make sure to get something with overvoltage protection.

Also, read the fine print. One cheap "500W" power supply I bought
computes its wattage rating by adding the total wattage for each rail,
assuming that all the other rails are unloaded. This is a next to
useless measure for a real PC. The actual maximum power rating for the
unit is only 282W.
Click to expand...


You were lucky to find a label on it that honestly stated
the true max rating... usually that is omitted.
 
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