i think i need a monster PSU.. how many watts will it take?

[Vesper8]

hi everyone

ok so.. i got a pretty power hungry machine right now

right now i have a SEASONIC S12-500HT 500W ATX12V powering it all

i have 3 hard drives, 2 dvd writers, 9 fans and currently a 6600gt

you can see which HDs and all that in my sig below

i had problems recently which I thought were due to the power supply when I just added the 300gb maxtor drive.. after some fiddling and changing which power cables connects to what etc.. i got it to work

here's my issue.. i am about to upgrade my 6600gt by a top of the line card.. and by that I mean either the x1900 or the upcoming g71. I know those cards pull a hell of a lot of juice.. and a lot more than my current 6600gt

i am not going sli.. that's a certainty

but i don't want power troubles... i think it's pretty obvious my 500w psu won't be able to provide with this new video card.. so i need to upgrade that.. but to what? a 700w? more?

need your input guys.. what monster psu should i be looking into? i want a quality.. low noise.. high efficiency and high power psu that'll do the job of powering all my components and make it look easy

thanks!

 

[Malladine]

You'll be fine with that 500W seasonic imo. An FX55 cpu with the x1900xtx consumes less than 400W. You HDDs and fans combined are probably no more than 50W.

 

[Vesper8]

hrmm...

this power consumption calculator says otherwise

http://www.jscustompcs.com/power_supply/Power_Supply_Calculator.php?cmd=AMD

it says i need over 400w with my current configuration !

and looking at the power consumptions from the anandtech x1900 review.. which claims a single x1900xtx uses an incredible 350w !!!!!! there is no way my power supply would be enough if this is to be believed!

http://www.anandtech.com/video/showdoc.aspx?i=2679&p=15

 

[Matthias99]

Originally posted by: Vesper8
hrmm...

this power consumption calculator says otherwise

http://www.jscustompcs.com/power_supply/Power_Supply_Calculator.php?cmd=AMD

it says i need over 400w with my current configuration !

It's overestimating. By a lot.

and looking at the power consumptions from the anandtech x1900 review.. which claims a single x1900xtx uses an incredible 350w !!!!!! there is no way my power supply would be enough if this is to be believed!

http://www.anandtech.com/video/showdoc.aspx?i=2679&p=15

That's measuring the ENTIRE SYSTEM. And at the wall, so it's not taking the PSU's efficiency (or lack thereof) into account. Please don't try to interpret data you don't really understand.

There is NO WAY that an S12-500 could not power your system regardless of what GPU you put in it. You have, at most 200-250W worth of gear.

 

[Malladine]

Well, that's full system load afaik. Don't know if that jscu website is to be believed or not so i won't offer an opinion there.

Let's say they are right. In that case you might as well go for a 650W. That will power any single card gaming setup with the fans and hdds you have with ease.

I wonder why the power consumption of vid cards goes up when the process shrinks, as opposed to cpus. EG 130nm amd use 80W, 90nm use 67W. Vid cards went to 90nm and power consumption rocketed. I guess because the clocks are so much higher? Anyone knowledgeable here?

 

[Matthias99]

Let's say they are right. In that case you might as well go for a 650W. That will power any single card gaming setup with the fans and hdds you have with ease.

There's no way you can get a single-CPU/single-GPU system over maybe 300W of actual power use without either a) EXTREME overclocking, or b) adding tons and tons of peripherals, like dozens of 10K/15KRPM hard drives.

I wonder why the power consumption of vid cards goes up when the process shrinks, as opposed to cpus. EG 130nm amd use 80W, 90nm use 67W. Vid cards went to 90nm and power consumption rocketed. I guess because the clocks are so much higher? Anyone knowledgeable here?

You're looking at something like 3-4x the transistor count, and almost all of it is logic (compared to a lot of the transistors in general-purpose CPUs being dedicated to the L1/L2/L3 cache). The processing output of a modern high-end GPU (in FLOPS) is simply staggering compared to what a general-purpose CPU can do, so it's going to put out a lot more heat even if they are equally efficient (in terms of Watts/unit of computation).

Also, AMD is using a 90nm SOI (Silicon-On-Insulator) process, and I don't know if ATI/NVIDIA are doing the same, so they may not really be comparable from even a process perspective.

 

[ribbon13]

Originally posted by: Matthias99
There's no way you can get a single-CPU/single-GPU system over maybe 300W of actual power use without either a) EXTREME overclocking, or b) adding tons and tons of peripherals, like dozens of 10K/15KRPM hard drives.

A dozen 15K drives would be about 220w by itself.

 

[Finns14]

Originally posted by: Malladine
You'll be fine with that 500W seasonic imo. An FX55 cpu with the x1900xtx consumes less than 400W. You HDDs and fans combined are probably no more than 50W.

QFT

 

[w00t]

The Seasonic S12 will hold up its end.

 

[Matthias99]

Originally posted by: ribbon13

Originally posted by: Matthias99
There's no way you can get a single-CPU/single-GPU system over maybe 300W of actual power use without either a) EXTREME overclocking, or b) adding tons and tons of peripherals, like dozens of 10K/15KRPM hard drives.

A dozen 15K drives would be about 220w by itself.

Alright, so I exaggerated slightly.

A high-end AMD CPU is ~100-110W, and the absolute top-end graphics cards you can get (barring things like the one with two 7800GTs on one card) now are around 120-130W. With some overhead for the MB/RAM and a couple hard drives, that's in the neighborhood of 300W. The people who somehow think a good-quality 400-450W PSU (let alone a 500+W one) will not power their relatively pedestrian system are just not doing the math.