[Traeumt]

I am using a tx750w and it shows around 11.950V in speedfan app and my rams seems to be unstable is it the cause or ??

 

[meticadpa]

No. Voltage reading is often inaccurate using software anyway, and you are well within ATX Spec.

ATX Spec is plus or minus 10% on each rail, so you're safe between 10.8V and 13.2V.

 

[TwoCables]

10%?! I thought it was 5%! Who's lying to me?!

 

[Traeumt]

great to know that it reads like 12.40 in bios btw

thank you guys

 

[meticadpa]

Quote:

Originally Posted by TwoCables 10%?! I thought it was 5%! Who's lying to me?!

It depends on the rail.

On the 12V rail, the tolerance is 10%. The 5V rail is 5%.

 

[TwoCables]

Quote:

Originally Posted by meticadpa It depends on the rail. On the 12V rail, the tolerance is 10%. The 5V rail is 5%.

Well damn. What about the 3.3V?

 

[meticadpa]

Quote:

Originally Posted by TwoCables Well damn. What about the 3.3V?

*shrugs*

I'd rather not be proved wrong on this, so someone wiser than I will come in eventually.

http://en.wikipedia.org/wiki/ATX

I'm a little confused by this.

But either way, the OP is fine.

 

[TwoCables]

Quote:

Originally Posted by meticadpa *shrugs* I'd rather not be proved wrong on this, so someone wiser than I will come in eventually.

hehe

I've always been told +/- 5% on all of them. After all, how many really good PSUs deviate more than +/- 5% on the +12V?

 

[meticadpa]

Quote:

Originally Posted by TwoCables hehe I've always been told +/- 5% on all of them. After all, how many really good PSUs deviate more than +/- 5% on the +12V?

I edited my post.

Pretty much no good power supply does.

 

[TwoCables]

Quote:

Originally Posted by meticadpa I edited my post. Pretty much no good power supply does.

I bet the tolerance refers to the standards. I mean, maybe it means that if it deviates more than that, then it's not following the standard.

 

[shinji2k]

ATX spec is +/- 5% for the 3.3V, 5V, 12V and 5VSB rails and +/- 10% for the -12V rail. Realistically a decent PSU shouldn't vary by more than about +/- 3% unless it is a group regulated unit.

Page 22

 

[Phaedrus2129]

^Shinji is right. 5% on the three main rails and 10% on the -12V. I forget if the +5VSB is 5% or 10%.

But the main rails really shouldn't vary by more than 3%, and I like to see them tighter still. Last time I checked all of my rails on the TX750W were within 1-2% of nominal.

 

[detroitpc313]

Quote:

Originally Posted by Phaedrus2129 ^Shinji is right. 5% on the three main rails and 10% on the -12V. I forget if the +5VSB is 5% or 10%. But the main rails really shouldn't vary by more than 3%, and I like to see them tighter still. Last time I checked all of my rails on the TX750W were within 1-2% of nominal.

thats abousolitly wrong.. on your 12v rail, +5v,+3.3v rails they should all be + or - 5% no more and no lease im 100% sure about this.. Use a program called OCCT to test your power supply it well test all rails on your power supply and measure UNDER LOAD what your 12,5,3.3 volt rails are.. good luck pm me or message me on msn i just added you if you need any help

 

[Phaedrus2129]

I know what OCCT is, and I also know that its voltage monitoring is crap. I'll run it to humor you though.

And... +/- 5% no more no less? So you're saying that 11.4V or 12.6V would be preferable to 12.00V? Incredible insight.

If a PSU can't manage +/-3% on the main rails (+12V, +5V, +3.3V) then it's garbage. In my experience when a PSU falls below 11.6-11.7V on the +12V rail you start to see graphics artifacting. Over about 12.4V can cause the VRM on your mobo or graphics card to heat up pretty bad; not enough to cause short term damage, but it can cause damage over the long run. The ATX spec is a good guideline, but it's too loose in some respects, especially voltage regulation.

 

[TwoCables]

Quote:

Originally Posted by Phaedrus2129 I know what OCCT is, and I also know that its voltage monitoring is crap. I'll run it to humor you though. And... +/- 5% no more no less? So you're saying that 11.4V or 12.6V would be preferable to 12.00V? Incredible insight. If a PSU can't manage +/-3% on the main rails (+12V, +5V, +3.3V) then it's garbage. In my experience when a PSU falls below 11.6-11.7V on the +12V rail you start to see graphics artifacting. Over about 12.4V can cause the VRM on your mobo or graphics card to heat up pretty bad; not enough to cause short term damage, but it can cause damage over the long run. The ATX spec is a good guideline, but it's too loose in some respects, especially voltage regulation.

Yeah, that spec is basically saying that if it deviates any more than +/- 5% on the +3.3V, +5V and +12V, then it's out of spec and it's not conforming to the standard (and in my opinion, it should then be considered to be a big hunk of garbage).

However, Phaedrus: he meant no more than +/- 5%. He didn't meant that something like exactly 12.00V is less preferable. This is just one of those things that's a bit tricky to verbalize.

 

[Phaedrus2129]

OCCT says +12V is at 11.93V (just within 1%) and +3.3V is at 3.26V (also just within 1%). There was no +5V reading. Everything looks great, except my GPU temperature is higher than I usually like it (it hit 75C, at which point my fan kicks into 100% mode and it dropped to 72C).

 

[Phaedrus2129]

Quote:

Originally Posted by TwoCables Yeah, that spec is basically saying that if it deviates any more than +/- 5% on the +3.3V, +5V and +12V, then it's out of spec and it's not conforming to the standard (and in my opinion, it should then be considered to be a big hunk of garbage). However, Phaedrus: he meant no more than +/- 5%. He didn't meant that something like exactly 12.00V is less preferable. This is just one of those things that's a bit tricky to verbalize.

Eh, I see what he meant now. Wording was a bit off. Sorry for that mate.

If a PSU can't manage +/-5% then it shouldn't be used as anything more dignified than a doorstop.

If the +12V goes below 11.4V most computers can't even function at all. At higher than 12.6V you're going to have bad overheating of the VRMs and possible hardware damage. If the +5V goes as high as 5.3V you're going to start losing hard drives. The 3.3V is filtered through the mobo's VRM, so it won't have an opportunity to fry the RAM if it's too high, but it will contribute to overheating.

But yeah, if OCCT is accurate in any way then my TX750W's voltages stay within 1% of nominal under my computer's maximum load. EDIT: The +3.3V is at 3.28V on idle, 3.26V during the PSU test. +12V stays constant at 11.93V.

 

[shinji2k]

In my experience with software voltage measurements, it is either way off or close enough to get a rough idea where it is at. If your 12V is displayed as 13V and your computer is still running, it's pretty obvious the program is reading the wrong sensor or calculating the voltage wrong. If it's in the ballpark of where it should be then it is programmed properly, but I wouldn't put too much value in the numbers. It's fine for a quick glance but if you are trying to see how well your PSU regulates voltages with different loads, it's useless to try and rely on software. Even a $10 multimeter will be much more accurate.

edit: And to the OP, we didn't forget about you. Assuming the software readings are in the ballpark, your 12Vrail is just fine. Even if the 12V rail wasn't fine, RAM is usually ran off the 3.3V rail. The state of the 12V won't have an affect on your RAM.