Need help checking the voltage on my VDimm with a Fluke 7-300 tester?

[Toro 45]

I adjusted my 3.3V pot by watching the bios setting and was told the onboard monitoring is not that accurate, so I want to check it with a tester. I borrowed a Fluke 7-300 tester and I want to see exactly how much voltage I'm getting to the ram.

I have never used one, I was told "to check the mosfet closet to my ram. Thats usually where its at. Make sure your voltage meter is set to voltage and not ohms or something. That can cause major problems." "

My meter just has on on/off button and says Automatic Selection,VAC,VDC,OHMS. no individual options. Now I just need to figure out which mosfet it is...

Edit: I think I found it it's black and says Richtec on top of it with 5 silver bars/pins connecting it to the mobo, do I touch one of the bars/pins or on the top black part?

Thanks for the help, I really want to be sure how much volts I'm using before I go to 3.5V on this ram. Not to worry, I don't plan on using it untill I get a good qualified answer.

[Malves]

What board?

[Toro 45]

DFI Lanparty nf3 250gb

[bachus_anonym]

Something for you to remember - any board has one common vdimm measurement... DIMM slot ;)

http://www.xtremesystems.org/forums/attachment.php?attachmentid=27101

[Malves]

The vdimm mod guide you followed should show the check point for this board.

:lol: Just saw your sig. Sorry! :sofa:

[Toro 45]

Something for you to remember - any board has one common vdimm measurement... DIMM slot ;)

http://www.xtremesystems.org/forums/attachment.php?attachmentid=27101

That was my first thought but I was told not to check it there and check the mosfet instead? So just ground the black probe on the case and stick the red probe in the dimm slot with computer running, on correct? (sorry for the newb questions but I've never used a tester before and don't want to screw anything up)

Malves I didn't do a vdimm mod on the board. I bought a Fortron 53W with adjustable pots.

Thank You both for your help.:toast:

[bachus_anonym]

yes. gound (black probe) to the case or screw that holds the board onto motherboard tray and red probe to pin7 in the DIMM socket... you'll be fine :)

this way there's pretty much no chance you short anything on the board (or legs on the mosfets). pretty safe in my opinion and very accurate ;)

[Toro 45]

Pin7 is pretty specific I was just going to stick in the slot :explode2:

Looking at the board is that 7 down from the top of the board and left side of slot?

[bachus_anonym]

Pin7 is pretty specific I was just going to stick in the slot :explode2:

Looking at the board is that 7 down from the top of the board and left side of slot?
Good you did not do that :uff:

I'm not sure what the layout is on DFI NF3 but when you look at the DIMM slot close enough you will see numbers on both ends 1 and 92... Those are first and last pin numbers in upper row...

Start from 1 and make your way to 7.... Voila!

[Toro 45]

Thank you, that worked perfectly. it's reading about .40 over the bios reading.

Is there an easy way to check the exact reading on my 3.3volt and my 12volt rail?

[bachus_anonym]

You can measure your PSU's 3.3v/5v/12v rails on ATX connector that plugs into the mainboard:

3.3v - ORANGE wire
5v - RED wire
12v - YELLOW wire

Same way as you did with vdimm readings: black probe to the ground and red ontro the ATX connector. This time it might be kind of tricky, as you'll have to use little bit more force to stick red probe into the connector.

This is pretty accurate... But you can also try to measure same way on e.g. SATA connector that comes out from your PSU.

Check voltages while IDLE and under heavy LOAD, to see if your rails fluctuate.

EDIT: In case when measuring rail you can also use a molex connector's BLACK wire as ground, too ;)

[Toro 45]

I notice I have several red wires and 3 orange wires on my atx connector, just pick anyone of them?

[bachus_anonym]

I notice I have several red wires and 3 orange wires on my atx connector, just pick anyone of them?
they are all the same... ;)

[Toro 45]

Here is what I found:

3.3=3.68V
12V=12.35V
5V= 5.26

On my DFI mobo you have to raise the 3.3V rail to get higher vdimm, right now even with 3.68 I get a max volt of 3.45vdimm.

2 questions:

1- Would it be ok to raise the 3.3v rail higher,say to 3.8-3.9?

2- Are my 12V and 5V rail to high? (The pots are not marked in my Fortron so I had to adjust those while searching for the 3.3V rail)

I'm trying to squeeze a few more drops of speed out of my Twinmos UTT ram, in case I didn't mention that earlier.

[bachus_anonym]

I'm glad you getting yourself familiar with DMM :thumbsup:

Your rails look pretty good to me. Nice and high :D 12.35v and 5.26v is OK.

Having 3.45v max vdimm with 3.68v on rail sounds about right... You generally need to have your rail 0.20-0.25v higher than desirable vdimm under LOAD. Now, this is what many people will tell you as far as bumping rails: +/- 5% is what PSU manufacturers say. +10% is what PC components are supposed to be designed to withstand.
I think you should be alright to bump to 3.8v, probably even 4v would not hurt in a long run. But nobody really knows for sure. Same as "how much vcore can kill my cpu" type of question.
I've had 3.7v on one of my PCs for about a year now... Nothing happened so far. MOst others have 3.3v rail @ 3.5-3.7v for 24/7 non-stop use... So it's totally up to you.