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What wattage size is good

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Last response: in Components
January 11, 2009 3:07:59 AM

Ok I'm planning to buy a ATI Radeon HD 3870 3CF 3x512 MB I'm upgrading from a GForce 6100 and my PC only has a 300 watt power supply what size would be good.

More about : wattage size good

January 11, 2009 3:36:51 AM

but would a 500w be just as good I'm not planning to do anything to just yet and I don't have a lot of money right now and I'm have some what of a dead line to get the ATI Radeon HD 3870 3CF 3x512 MB card its on sale and it ends in a few days and the place that I'm getting it at doesn't have any 600w supply in stock. and I forgot to say what kind of PC I have its mostly used as a family PC and not just for gaming.

Gatway PC

AMD 64 prosesser 3500+ 2.2GHz
200 gigs
Windows Xp
DVD/Burner drive
CD Drive
just the basic stuff,

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January 11, 2009 12:20:54 PM

I would say 500W would be cutting it fine.

How much RAM have you got? and I'm assuming your Windows XP is 32bit?
I ask because 3x512MB GPUs will use 1.5GB of your 4GB of memory addresses (assuming 32bit).

Also you do realise that it'll still only give you 512MB of effective video memory, and with that CPU you might find it a bottleneck.
a b ) Power supply
January 11, 2009 1:20:44 PM

is the processor an X2?
January 11, 2009 3:58:53 PM

@ DeVastatoR_UK I have 1024 in the ram and its 32-bits, the ram is down to 896 due to all the crap the family put on it.

and to mi1ez its just has on processor we got it 6 months give or take before the Dual processors started to come in. and the PC is two years old and still runs like its brand new.
a b ) Power supply
January 11, 2009 4:46:53 PM

Wattage is not that important. What's important is the Amps! Base a PSU on (in order):

1. Amps (esp. on +12)

2. Build quality (ie Corsair > Rosewill) [+1 for the 650TX linked above]

3. Wattage

Note: Your CPU MAY bottle neck. Also what games and what resolution do you plan to play at? Any thing below 1900*1200 is a waste with CrossFire.
January 11, 2009 5:38:07 PM

I have right now Hell Gate London haven't played yet, and I'm planing to get Diablo 3, Star Craft 2, those are the only right now that I'm planning to get, and maybe Unreal and what ever else that grabs me. and my monitor I have right now can go up to 1280 by 1024 planning to get a better one in a few months.
January 11, 2009 6:36:32 PM

why 3CF 3870s?

check out toms graphics card charts. Some 3CF setups dont scale, they lose a lot of performance in some benchmarks. some times a single 3870 will beat a 3CF setup.

i think it is a waste. get a 4830/4850. or just 2 3870s. 2CF 3870s scale much better across all games. 3CF dont.

as far as wattage, get the most you can afford with a good brand name. 650w plus and ~50 amps plus combined 12v rail. I dont even think that will be enough amps.
January 11, 2009 6:37:53 PM

1280 x 1024.

Crossfire will help very little at that res.
January 11, 2009 6:43:07 PM

why waste so much money on 3 3870;s just get one single 4850 which would perform better anyways, other than that 500watts should be enough but i would see about 600 or more.
January 11, 2009 6:47:54 PM

It doesnt matter how many 3870s you get, they still suck at handling AA. Any 4xxx will handle AA much better, especially at higher res.

Edit: a friend has a single 8800GT oc edition. It runs as good as my 2 CF 3870 setup.
January 11, 2009 9:16:26 PM

I'm slowly going to turn it into a full gaming PC and a friend of mine can get for me at a place he works at a better price and after the card is in I'm adding a 1T Hard drive better monitor and all in all everything that's in it right now is going into another family PC when I upgrade it.
January 11, 2009 10:39:32 PM

50bmg whats funny is the 3870's were designed to compeate with the 8800gt's lol, he must have the zotac one cause usually they are very close
January 11, 2009 11:11:50 PM

I would seriously consider 4850 CF. The 4x00 series has much better AA performance than the 3x00 series. Usually, 3 video cards in a multi-GPU array will not scale very well. Sometimes 2x CF will beat 3x CFX. However, CF does scale well going from 1 to 2 cards. I've seen examples of precisely 100% scaling like in Ghost Recon 2 @ 2560 x 1600 with 2x 4850. It went from 31 FPS to 62 FPS.
January 12, 2009 1:26:12 AM

As amd_overclocker said
50bmg whats funny is the 3870's were designed to compeate with the 8800gt's lol, he must have the zotac one cause usually they are very close

My friend has the same card I want and he said its one the best he had put in his pc, and he knows his his computers like its part of him (plus he works with pc every day) and the funny thing was I was going to get the G force 8800 and he stopped me from getting it just look at the Chart/graph section of the site and the 3870 HD is third from the top...
January 13, 2009 2:29:41 PM

yes, the 3870 was made to compete with the 8800gt. It does compete, but it just isnt as good. I have 2 3870s. i like them. My buddy's is an OC version so that does help, but my 2 3870s are OC versions. I still get better FPS than he does, but only 10-20fps more than his single 8800GT OC.

The 3870 in CF scales very well, but 3CF doesn not. If i were you, i would get 2 of the 3870s and leave it at that. The 3rd card will be a total waste of effort and money.

That must be an old GPU chart. The 3870 is down the list now; 295GTX, 280GTX, 4870x2, 260GTX, 4870, 9800GTX+, 8800Ultra/GTS, 4850, 8800GT then the 3870.

Don't get me wrong, I like the 3870. Dollar for dollar at its current price point it is still a very good deal. Just don't get 3.