Enermax PSU question

[KennyH]

Hey guys, been experiencing a random reboot every now and then and was wondering if my PSU could be a problem. This is on a AXP 2000+, two HDD's in RAID, two optical drives. Motherboard has no leaking, bulging caps. Here is what the BIOS says:

+3.3V -- 3.23V
+5V -- 4.73V
+12V -- 12.20V

The +5V line seems a little low to me. What do you guys think?

 

[Corporate Thug]

i concur, the 5v rail seems problematic.

edit: the 5V rail on my antec 380W truepower never falls below 4.84V with the rig in sig

 

[KennyH]

Thanks for the reply shady06, the AXP is an old Palomino core that runs at 1.75V default core. Maybe this could be a precursor to the problem?

 

[jaeger66]

5v is low, but within spec(+/- 5% or so). Your CPU runs entirely off the 12v rail, so your problem is likely elsewhere.

 

[bjc112]

Originally posted by: jaeger66
5v is low, but within spec(+/- 5% or so). Your CPU runs entirely off the 12v rail, so your problem is likely elsewhere.

I think Pentium 4's run completely off the 12v rail...

But AXP runs completely off the +5v...

🙂

 

[Mark R]

But AXP runs completely off the +5v...

It depends on the motherboard. I've checked my Abit NF7, and it definitely powers the CPU from 12V.

I don't know about others, but due to the high power consumption of the AXP CPU, I'd guess that the vast majority do. A good clue is the presence of the square 4 pin 12V connector - if the CPU didn't need the 12V supply, this connector wouldn't be necessary.

 

[jaeger66]

Originally posted by: bjc112


But AXP runs completely off the +5v...

No it doesn't.

 

[jaeger66]

Originally posted by: Mark R

But AXP runs completely off the +5v...

It depends on the motherboard. I've checked my Abit NF7, and it definitely powers the CPU from 12V.

No, it does not depend on mobo. The AXP is a 12V CPU. The last CPU to run off the 5V rail was the P3.

 

[bozo1]

Two of my Enermax's crapped out on me in the last year or so - both with the 5-volt line getting weaker and weaker until my system was no longer stable.

And as far as the 12-volt vs 5-volt deal with AMD mobo's - it depends on the mobo - some use the 5V line, most newer ones use the 12V line.

 

[jaeger66]

Originally posted by: bozo1
Two of my Enermax's crapped out on me in the last year or so - both with the 5-volt line getting weaker and weaker until my system was no longer stable.

And as far as the 12-volt vs 5-volt deal with AMD mobo's - it depends on the mobo - some use the 5V line, most newer ones use the 12V line.

Where the hell are you people getting this idea from? The Athlon is a 12V CPU.

 

[Dulanic]

Originally posted by: bozo1
Two of my Enermax's crapped out on me in the last year or so - both with the 5-volt line getting weaker and weaker until my system was no longer stable.

And as far as the 12-volt vs 5-volt deal with AMD mobo's - it depends on the mobo - some use the 5V line, most newer ones use the 12V line.

I had the same problem.... but as I tested it more it was not the PSU, it was 2 EPOX MBs I had... over time my 5V dropped all the way to 4.4V and I couldnt even run a 1600+ at 800Mhz.... it crashed at anything beyond 700. Then I switched PSUs and it went up for a while and I ended up having the same problem. Now Im using the same Enermax 400W that I was with the EPoX KT333 MB that had 4.4V on the 5V, but now Im using it with my A7N8X and it works 100% OK.

 

[Dulanic]

Originally posted by: jaeger66

Originally posted by: bozo1
Two of my Enermax's crapped out on me in the last year or so - both with the 5-volt line getting weaker and weaker until my system was no longer stable.

And as far as the 12-volt vs 5-volt deal with AMD mobo's - it depends on the mobo - some use the 5V line, most newer ones use the 12V line.

Where the hell are you people getting this idea from? The Athlon is a 12V CPU.

NO it's not. It is a 1.75V (+/- a little depending on model etc..) however the MB converts either 12V or 5V into that voltage. The MB does this, so that's why some can use 5V to power the CPU or they can use 12V. Heck some CPUs now draw over 50 Amps, go look at your PSU, promise it doesnt offer that much power on any single line. But when you convert voltage... at 100% efficency you can turn 10 amps at 100V into 100 amps at 10V.

 

[jaeger66]

Originally posted by: Dulanic



NO it's not. It is a 1.75V (+/- a little depending on model etc..) however the MB converts either 12V or 5V into that voltage. The MB does this, so that's why some can use 5V to power the CPU or they can use 12V. Heck some CPUs now draw over 50 Amps, go look at your PSU, promise it doesnt offer that much power. But when you convert voltage... at 100% efficency you can turn 10 amps at 100V into 100 amps at 10V.

Oh for god's sake. You are confusing the issue of the mobo's onboard VRM with the power supply rails. What happens to the current after it is drawn is not the issue. All Athlons and P4s draw current from the +12V rail. Period.

 

[jaeger66]

And BTW, you mean 50 Watts, not 50 Amps.

 

[bandana163]

As i see, the 12V shouldn't be a problem. The most fans get that for example. In my situation, the 12V is almost always stable 11.69V, the 3.3V is 3.3-3.45V and no problems occour. The 5V is rock solid, though. (Huntkey 400W PSU)

 

[Mark R]

All Athlons and P4s draw current from the +12V rail. Period.

That's quite simply not true. The CPUs draw power from the motherboard's VRM.

Depending on the design the the motherboard, the VRM may take power from either the 12V or 5V supply. Intel's recommendation to motherboard manufacturers was that they use 12V for the P4.

The first few generations of Athlon MB used 5V (this was the reason for 'AMD approved' PSUs - most PSUs didn't have strong enough 5V lines). The most recent Athlon MBs use 12V.