Testing Your PSU Rails

[Shyfty]

Thecleaner for President! I went through the sensors and voila problem solved! So simple! Thanks again!!

[Orion]

Originally Posted by webstien

My voltmeter says my 12 volt fluctuates A LOT.

From 11.76 to 11.93 volts.

Whereas my 3.3 is solid @ 3.35Volts
and my 5 volts is 4.93-5.08volts.

Does the voltage on the highend powersupplies stay constant or fluctuate like this also?

This is a cheap case power supply and it only has 12Amps on the 12volts, isnt that horrible if i want to overclock?
Should i switch out this piece of junk?

11.76 to 11.93 is just 1.4% and that is well within the usual specs of 5%. Only PSUs like the OCZ give specs on the +12v line of less than 1%.

12 amps doesn't seem that much but a good PSU like the Fortron only has 15 amps.

Your +5 is more like 3% but still within 5% specs.

Unless you are planning a massive overclock, I think your PSU is fine.

[davidhammock200]

Higher end PS's fluctuate less, this instability can affect your OC.

[Shyfty]

Originally Posted by Shyfty

Thecleaner thanks for the descriptive guide...I am quite new to all this, but having fun learning. My overclocking has not been as productive as I had originally hoped and several people suggested that my stock PSU may be part of the cause. Could you look at the attached screen shot and tell me what you think? Do I need another PSU? Please say yes I want to buy something!
Thanks,
T.

Thecleaner: You or someone else had asked my amps...sorry I have been distracted! Here they are :
PowMax: 400W overvolting
+3.3=28A, +5= 30A, +12 =25A

[Playful_Buffalo]

does reading from a molex give accurate results?

[davidhammock200]

Originally Posted by Playful_Buffalo

does reading from a molex give accurate results?

Yes, but there could be a drop going in to the MoBo or whatever due to a poor connection or something.

By measuring as close to the load as possible we get a better of what voltages the load is getting.

[TheCleaner]

wow, its been w hile since i last looked, i think i might have to check that out

if theres any difference between molex readings and atx cable readings (from the back of the plug, so the computer is on, and under load)

ill post back with results

[python134r]

I just checked my antec 550 eps p/s and everything is stable. Friggen software sux as does the bios, none are correct, finally got around to finding my fluke meter and testing it. Good Thread.

[MarkJohnson]

well, you finally conviced me to buy a Multi-Meter. Now that you've shown me just how to test my psu's.

Kudos
-=Mark=-

[rob2687]

Something I noticed on my p4p800-dlx and E-dlx.
Measuring the 12 volt from the 4pin molex and AUX power connector is different from the values Im getting off the boards themselves.

12v off the 4 pin molex: 12.1v solid no matter what.

12v off a choke: 12.1v Idle/ 11.79 Full load.
(Which is exactly the same readings I get through software readings.)

[davidhammock200]

Originally Posted by rob2687

Something I noticed on my p4p800-dlx and E-dlx.
Measuring the 12 volt from the 4pin molex and AUX power connector is different from the values Im getting off the boards themselves.

12v off the 4 pin molex: 12.1v solid no matter what.

12v off a choke: 12.1v Idle/ 11.79 Full load.
(Which is exactly the same readings I get through software readings.)

Make sure the plug is pushed in all the way & that none of the pins have backed out.

[General Zod]

Great thread! my OCZ is rock stable so far! my 12V is 12.30! highest of all 3 of my PSUs.My friend told me that 12.7V would help my Oc do any of you reccommend this? I will check my 3.3V next and I want to make my 3.3V go 3.65VV is this safe? I read that this helps stabilize ram overclocks,I think it was Hiprp5 from Xs who said it.

Tested 3.3V rail and its at 3.42! If only I can raise my OCZ's 3.3V rail to up the Vdimm

[davidhammock200]

Originally Posted by Negative Design

Great thread! my OCZ is rock stable so far! my 12V is 12.30! highest of all 3 of my PSUs.My friend told me that 12.7V would help my Oc do any of you reccommend this? I will check my 3.3V next and I want to make my 3.3V go 3.65VV is this safe? I read that this helps stabilize ram overclocks,I think it was Hiprp5 from Xs who said it.

Tested 3.3V rail and its at 3.42! If only I can raise my OCZ's 3.3V rail to up the Vdimm

No the AMD/Intel spec for all voltages is +/-5%, stay within it about 3.4, 5.1, 12.2 seems best.

[General Zod]

that makes sense do 3.4 even if my ram is running 3.3V too ho well I can dream I guess lol.

[Revolt26]

Great thread ...im going to bring my volt meter home from work and check mine since my computer has been suffering psu failure symtoms recently ..

Thank you

Eric

[nelvick]

~@c@~ Exelent Post !!

[sin0822]

Possibly one of the most informative guides out there, i also discovered i could ground the block one to a molex and measure voltages throughout my mobo, like vcore, vdimm, and fan.

[discobiscuits]

got my multimeter today. I will test the volts on my new PSU which should be here this week, or next week sometime. Shipping from netherlands owns me.

Anyway My rig is odd.

The 420 Raidmax PSU
+12V = 11.89 @ idle | 11.69 @ load (Prime95)
+5V = 5.03 @ idle | 4.85 @ load (Prime95)

Didn't feel like doing the +3v lol

[Cappy]

I guees I'll have to back probe the ATX connector to get my 3v rail, due to the fact that i dont have an aux power connector on my Turbo Cool 510 D

[davidhammock200]

Originally Posted by discobiscuits

got my multimeter today. I will test the volts on my new PSU which should be here this week, or next week sometime. Shipping from netherlands owns me.

Anyway My rig is odd.

The 420 Raidmax PSU
+12V = 11.89 @ idle | 11.69 @ load (Prime95)
+5V = 5.03 @ idle | 4.85 @ load (Prime95)

Didn't feel like doing the +3v lol

Better get ready to buy a new PS.

I recommend replacing it now, prior to total failure as these often take other parts with them.

Originally Posted by Cappy

I guees I'll have to back probe the ATX connector to get my 3v rail, due to the fact that i dont have an aux power connector on my Turbo Cool 510 D

That is why the probes are so sharp.