480 Watt power supply not enough for a Prescott?

[AdamK47]

I recently bought a 2.8E D0 stepping Prescott P4 in the hopes of getting it to 3.5GHz on a 250MHz FSB. The CPU previously in my system was a 2.4C @ 3.0GHz, so I knew the rest of the system could handle it. Along with the CPU I bought a Thermaltake 735 heatsink/fan and a 480W Thermaltake power supply.

I got everything setup and powered on. Everything was fine at default clock speeds, so I decided to start the overclock. Set the bus to 250MHz FSB and left the voltages at default. It got into windows just fine, but didn't pass Prime95. So I decided to raise the vcore to 1.45V. Everything seemed to be stable in Prime95 after that, or so I thought. After about 30 minutes the system just completely shut down. I had to unplug the AC from the power supply and reconnect it before I could power on again. I originally thought it was the temperature getting too high, but just before it happened the second time I was watching the temps. It never got above 60C, which is pretty good for a Prescott. I decided to just overclock at default voltage. The highest I got was 3.36GHz. Pretty good, but not what I wanted.

After about two weeks at that speed I decided to try a better power supply since I got the impression that having to recycle the AC on the power supply was a sign something was tripping. I got the Antec 550W power supply and went for 3.5GHz at 1.45V and everything has been fine since, temperatures and all.

Bottom line... If you're going to overclock a Prescott P4 with voltages higher than default, get the best power supply you can! Either that or stay away from Thermaltake power supplies.

 

[MDE]

Or just stay away from Thermaltake period...

 

[Lyfer]

Funnay, my Thermaltake 480 works fine with my A64 3000+ CG @ 2.25GHZ. I guess all PSU's aren't built the same. I bought it because it was cheap ($55) and it performed better than the Fortron 400W in anand's PSU roundup.

 

[Jhatfie]

The Thermaltake 480W is a decent power supply, but not for anyone looking to overclock a Prescott or A64. I have a Thermaltake 480W Silent Purepower and although it is a decent power supply, the weak 12v would show up when heavily overclocking my A64 3200+. It would dip down to 11.52v under load with my A64 at 2.6ghz and 1.7v and was not totally stable. I replaced it with a OCZ Powerstream 520W and the 12v rail will barely budge with it never going below 12.03 from the 12.08v idle and I am perfectly stable.

I just got a Epower 470W which has a strong 12v rail (28Amps), but it suffers from a similar undervolting problem when under load as the Thermaltake, just not as bad with it hitting a low of 11.58v under load.

 

[jiffylube1024]

People disagree, but personally I find Thermaltake to be a cut below Antec and Enermax. A 420W thermaltake I find about equivalent to a 350W Antec/Enermax; the 480W Thermaltake is outclassed by 460W Antec and (especially) Enermax PSU's.

 

[o1die]

Sparkle makes a pretty good ps also. My 300w with 12cm side fan runs a 2.8c at 3.64, and the 12v rail is at 12.03, dead on. Not bad for a $28 power supply.

 

[jswjimmy]

ya the Tt power supplys are good but not for overclocking, i just upgraded from a enermax 300watt to a Tt 420watt, its good but i can no longer overclock to 2.4ghz because of a low 12volt

 

[AdamK47]

I just looked up the specs on the Thermaltake 480W PS I had. The +12V line only supplies 18 Amps of current. Thats considerably less that my new Antec 550W which supplies 32 Amps. No wonder I had problems.

 

[fsstrike]

I have thermaltake butterfly 480w, and it SEEMs good :\ Could it be the reason I cant get to 2.4 @ on my stock hsf?

 

[AdamK47]

If it shuts the system completly down then it probably is the PS.