How much power do I need for 2 HD4850?

[kingtz]

Ok, so I ordered some stuff from newegg and got:

Antec earthwatts EA500 500W
http://www.newegg.com/Product/Product.aspx?Item=N82E16817371007

ASUS EAH4850/HTDI/512M Radeon HD 4850 512MB 256-bit GDDR3 PCI Express 2.0 x16 HDCP Ready
http://www.newegg.com/Product/Product.aspx?Item=N82E16814121253

along with some other parts.

They all just arrived about 20mins ago, but now I'm having second thoughts about whether I have enough power for future expansions.

I know that this is more than ample power as is, but I may want to get another HD4850 in the near future when I have a little more money.

My question is if this current PSU has enough juice for 2 HD4850, and if not, how much will I need? Recommendations much appreciated, but please keep in mind that I am working within a budge somewhat, so I'm looking at around $100 for the PSU. The cheaper the better .

 

[invisik]

the earthwatt500 is a great psu it will handle 2 4850 easily maybe a 3rd but u would be pushing it.
wats the rest of ur rig? would help more.

 

[dagger]

500w is pushing it. You should have gotten higher psu. There is expansion available though.
http://www.newegg.com/Product/Product.aspx?Item=N82E16817153069

Power consumption:
http://www.anandtech.com/video/showdoc.aspx?i=3341&p=22

 

[Kari]

^^if Anands system uses 302W I'd think 500W unit would be enough...

 

[dagger]

^^if Anands system uses 302W I'd think 500W unit would be enough...

Yeah, well, the cpu and everything else is idle. Besides, you don't want near full load on psu, it can't handle full load.

 

[kingtz]

Ok, there is my what I'm going to build:

ASUS EAH4850/HTDI/512M Radeon HD 4850 512MB 256-bit GDDR3 PCI Express 2.0 x16 HDCP Ready
http://www.newegg.com/Product/Product.aspx?Item=N82E16814121253

Antec earthwatts EA500 500W
http://www.newegg.com/Product/Product.aspx?Item=N82E16817371007

XIGMATEK HDT-S1283 120mm Rifle CPU Cooler
http://www.newegg.com/Product/Product.aspx?Item=N82E16835233003

OCZ Platinum Edition 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 1000 (PC2 8000)
http://www.newegg.com/Product/Product.aspx?Item=N82E16820227280

ASUS P5Q Pro LGA 775 Intel P45 ATX Intel Motherboard
http://www.newegg.com/Product/Product.aspx?Item=N82E16813131299

Intel Core 2 Duo E8400 Wolfdale 3.0GHz 6MB L2 Cache LGA 775 65W Dual-Core Processor
http://www.newegg.com/Product/Product.aspx?Item=N82E16819115037

Plus some stuff from my old computer that I'll be reusing:
74GB WD Raptor
A DVD burner
2x 300GB HDD for storage

So yeah, can the EA500 PSU still handle all of this and 2 HD4850?

 

[invisik]

im a 100% sure. it will be more then enough.
look at my rig. im running it on the same psu i have 2 gtx260 which consume much more power and i have a quad core.
ur system will probably use 350-400w max.

 

[-Fran-]

Each 4850 draws 110W on full load, that's ~10A per rail to each card.

That Antec shows: +3.3V@24A,+5V@24A,+12V1@17A,+12V2@17A,-12V@0.8A, +5VSB@2.5A

That means you still have ~6A (assuming 11A draw each, worst case scenario) on the 12V's for CD/DVD ROM and some HDD's. That's plenty of room for them

Esop!

 

[spathotan]

Ditch the OCZ Plat and get some Reapers instead. Ive had my 1066 Reapers OC'ed to 1200mhz for about 2 days once and they remained cool to the touch man, the little copper heatpipe on them actually does work, might be worth the extra $$ if you are paranoid about those things like I am.

Also, 500W on a quality PSU should be alright, but like others have said, its pushing it, I wouldnt go and add multiple hard drives abound and what not.

 

[-Fran-]

I found a little more info for the big picture:

- 1 DVDRW-ROM bay draws 2.0A MAX (that's one hungry unit though, avg is 1.8A on recording).
- 1 DVD-ROM bay draws 1.1A avg (not sure is this amount though...).
- 1 HDD (WD Caviar RE2, power hog) 10W -> ~0.9A.

Now, think about 80% efficiency overall, but 99% efficiency on those 12V rails. Make the math and see for yourself.

Esop!

EDIT: Spelling xP

 

[kingtz]

Thanks for your answers, everybody. I guess I'll be keeping the PSU after all. And yeah, like I was saying, at other than the aforementioned components, I won't be adding anything else - except maybe that 2nd HD4850.

 

[megamanx00]

That power supply should be fine. That Antec could be compared to some of the cheaply made 600W units. In the off chance that it isn't, that power supply should switch itself off if you draw too much power. You should also notice that high pitched whine that comes with pushing a power supply to it's limits. So yeah if you put in another 4850 and your PC doesn't shut itself off then your fine, if it does just upgrade your power supply ^_^

 

[magicbullet]

Each 4850 draws 110W on full load, that's ~10A per rail to each card.

That Antec shows: +3.3V@24A,+5V@24A,+12V1@17A,+12V2@17A,-12V@0.8A, +5VSB@2.5A

That means you still have ~6A (assuming 11A draw each, worst case scenario) on the 12V's for CD/DVD ROM and some HDD's. That's plenty of room for them

Esop!

very helpful comment, even i learn something to day.

i'll second it.