Will my psu (hx620w) limit my overclock?

bear_jesus

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I have a corsair hx620w running an ati 4870 with an amd phenom ii 965 c3 revision and i am curious if the amp's on the 12v rail may be limiting my overclocks. (not that i think it will effect it but there is 3 hard drives a corsair h50 and 10 fans, 4 120mm and 6 80mm)

The spec of the amp's on the 12v rails are 18A across 3 rails so 54A total and it seams that if my cpu is underclocked my gpu can reach 850mhz core with 1100mhz memory but only about 815mhz core and 1000mhz memory with my cpu overclocked and again with my gpu underclocked my cpu can reach almost 4.2ghz stable but with my gpu overclocked i can only reach 3.9/4ghz.

With my max gpu overclock gpuz gives a vddc current around 60A under full load but i don't know how much relavance that has to the avalible ampers on the 12v rail.

Any ideas? i am looking to get a new gpu at the end of the year that will draw more power than a 4870 under load and even more so if i overvolt/clock so i would like to work this out before i buy a new high end card.


*edit* does anyone know what kinda of amp's a phenom 965 and 4870 draw at stock speed/voltage?
 

bear_jesus

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well my next gpu will mainly depend on what the amd 6xxx cards offer, if the top end single chip card beats the gtx480 then it will proberley be the one if not then maybe an ati 5870, nvidia gtx460 sli or a gtx 480.

i am thinking about a psu upgrade if my new gpu/gpu's need it as i am looking at getting a new gpu now and then waiting for sandy bridge and bulldozer to get a new cpu, motherboard and ram
 
At stock the 965 is 125 watts and OC it to 4ghz with a 1.4 Vcore and you could see it draw as much as 160 watts at full. The 4870 with a little overclock on it you can expect to see around 200 to 215 watts when at full load more typical is only about 175 watts. I would say that it has nothing to do with your power supply and more to do with you are hitting the max OC for your components.

As for future GPU's even if you were to get a 5870 it would actually use less power then the 4870 isnt new tech great :)
 

bear_jesus

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In some ways yes the 5870 would idle at less power but i would over volt it and try and get it to around 1ghz core if the chip allows so i woudl assume at that point it was draw more power?
 

bear_jesus

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I assume the fact i get lower overclocks when choosing one or the other is maybe just causing the instability in the max overclocks of either when combined or something (has no idea what he is talking about lol)