Best graphics card for 22amp PSU

shrex

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I want to get the best graphics card i can for this system without changing PSU which has a 12v rail of 22amps. Currently i have a ATI 3850 installed.

It is a e6300 @3GHz, 4gb ram, 500gb hardrive, ati 3850.
 

croc

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Assuming that this is an older PSU, I'd be reluctant to push more than 212 watts total on that 12vdc rail.
 

croc

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...I ALWAYS believe marketing spin... :)
 

shrex

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Its a evo labs 450w psu, It doesnt have a red voltage switch. That video could be misleading, they never said they tested 75% of 12v rail, they tested 75% of 450w, they could be testing 100% or more of the 12v rail which would obviously result in failure.
 

Gulli

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The safest option would be a 4770, but a 4830 or even a 4850 will probably work as well, as long as you don't overclock anything and stick to one hard drive and DVD-RW.

I'd get the 4770.
 

Seems to be a unit that only comes with the case, I could be wrong though.
The only thing I could find out about it is that it's rated for 50,000 hrs @ 25c. ( You're not going to get anywhere near 50k hrs at actual operating temperature's, will see quite a bit less than 450 watts from it )
That, combined with only a 22 amp output, would have me changing it before doing any upgrades. ( a decent quality 400w will do 30a )
 

Gulli

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A 4770 would be ok, since it uses the same amount of power as a 3850.
 

shrex

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I actually bought it separately from ebay (new) for £11. I bought one of those killawatt type things that measures power drawn at the plug, and in games and in furmark the highest i got was 130ish, and with prime 95 and furmark running i got a peak of 156 watts.

Lets assume all of the 156 watts was on the 12v rail thats less than 60% usage or 13 amps out of 22 amps. Thats why i dont think i will bother with a quality psu costing £40 or more

The 4770 seems good it uses less power than the 3850 and performs close to a 4850.
 

4745454b

Titan
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Now your only problem will be that 25c rating. This is an operating temp it will never seen being stuck in a case right above a device that normally idles at 30c+, and gets a lot hotter then that while working. Add in its out heat it makes converting AC to DC, and you now get to worry about what will happen when those parts rated for 25c have to work at 35c-45c. I'm sure it will be fine though. You did spend a whooping £11 for it...
 

Gulli

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Even at full load, with a spinning DVD drive, his system plus a 4770 won't take more than 185W on the 12V, that's only 70% of full capacity, so it won't overload, even if it's one of those crappy PSU's that explode at 80% of full capacity.
Then again, for £11 it could be of such poor build quality that it'll just break down some day, regardless of how little of its capacity is being used.
 

4745454b

Titan
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If you read what I wrote, thats what I said. I never said the output would be to much, I said it will be working in conditions hotter then 25c, so you don't know what will happen when it blows.
 
What are you going on about man? He is already using an HD3850. It uses more power and therefore almost certainly gives off more heat then an HD4770.
Whatever the situation with his PSU is the upgrade will HELP, not hurt.