Infinity vDIMM huge undervolts?

[bigZ]

Let me explain first...

I'm in the process of modding up my infinity... I've not yet done vDIMM, but I've wired up a monitoring station for the DMM, so I've got the vDIMM monitoring point wired up... out of interest I checked the voltages...

at 3.1v vDIMM in bios (which according to bios, it reads 3.12v) I get 2.89v...

at 3.2v vDIMM in bios (according to bios read out, it's 3.22v) I get 3.00v...

and at 3.3v vDIMM in bios (bios read out of 3.34v) I get 3.11v...

http://bit-tech.net/images/bigz/vdimmvolts.jpg

This is over a 0.2v undervolt... has anyone else had this problem?

It won't matter in the long run to me because I'm doing the vDIMM mod, but I thought it would be interesting for people who aren't planning on modding the board... if anyone else could check this out to see if anyone else is having the same problem as me, that'd be great. No wonder I couldn't get anything above 240Mhz memtest stable... :rolleyes:

[ricjax99]

Hmm where did u get the board from and what PSU is that?

Did you check your +5V rail? if you look at the attached pic its the dimm mosfet leg highlighted 2, the vdimm is drawn from the +5V rail, you may already know this :)

This was not possible on my modded NF7 @3.20V vdimm (DDM):

240.5MHz (http://mywebpage.netscape.com/ricjax9903/benchies-ss/DFi/240x10-priming.gif)

[bigZ]

my rails are 3.28, 5.05 and 11.85 running off a GlobalWin SAF520

I'll check my 5v rail on the board though.

I got the board from CPUcity

[ricjax99]

I got mine from CPUCITY, it says rev A and theres a bit whited out (this is normal, see pic) and there is a made in china sticker on the back of the board.

http://mywebpage.netscape.com/ricjax9903/benchies-ss/DFi/DSC01545-w200.JPG (http://mywebpage.netscape.com/ricjax9903/rigpics/27-03-04/DSC01545.JPG)
*click for full image*

The reading on the board will be lower than what you are getting from a molex i would imagine. I get 5.22v on the board and 5.32v on the molex (PSU in sig, unmodded).

[mongoled]

Hey guys,

I havnt tested mine to see what i got on the multimeter, but ive already vmoded it so guess any results i show will be invalid now.

It is looking like that brd is undervolting loads, but like ricjax said if u are able to increase the 5v line then see if it effects your reading.

mong

[bigZ]

I guess so yeah, I'll be modding vDIMM anyway. :)

I've read from the board and get 5.05v and 5.09v at the molex :)

[STEvil]

Mine reads 3.0v @ 3.1v bios, 3.1v @ 3.2v bios, and 3.2v @ 3.3v bios..

5v @ 5.33v, 3.3v @ 3.35v, 12v @ 12.85v

[SAE]

Dunno what my dmm reading would be BUT if you experience these undervoltings NOW w/out vmod you very likely would have them after modding too.

The inaccuracy should continue... 3,5V in bios should be 3,4V at the according read out point.

Just my :2cents: :D

P.S. I would have to take away my sinks to get a measurement there.

[bigZ]

Thanks for the results STEvil, glad to see it's not just me having the undervolting probs :D


I've got a wire soldered to it for monitoring Hell-Fire style ;)

http://bit-tech.net/images/bigz/overall.jpg

Still modding away, when I get the time to ;)

[Walrusbonzo]

That's some modding going on there!!

Is that CPU, Chipset and RAM VMods?

[funktional]

my infinity overvolts a bit. Set to 3.3V it shows 3.34 in bios but I just measured 3.65V :eek:
Thats a nice 0.35 overvolt. Makes me like the board even more.
It also explains why the RAM is hotter and overclocks much better than on my Abit or EPOX ;)

PSU is a 350W TSP 3.28V, 4.92V and 11.6V

[bigZ]

Originally posted by Walrusbonzo
That's some modding going on there!!

Is that CPU, Chipset and RAM VMods?

vDIMM is wired up; but not soldered yet, vDD is soldered up and working, had it up to 2.11v with the stock cooling and an 80mm fan blowing over it.

vCore goes up to 2.08v before OVP kicks in.

The 4th mod is vSense.

I've still got more mods to do around the mosfets and also I've got the Capacitor mods still to do :)

I just have a complete lack of time at the moment, so I'm only getting a bit done at a time. :(

[Asio]

Originally posted by bigZ
Thanks for the results STEvil, glad to see it's not just me having the undervolting probs :D


I've got a wire soldered to it for monitoring Hell-Fire style ;)

http://bit-tech.net/images/bigz/overall.jpg

Still modding away, when I get the time to ;)

Is the wire u have right below the dimm banks the Vdimm readout ? (Just above the Vdimm Vmod)
U did the VDD mod aswel? What was the highest u got on 1.9Vdd?

Do u know what i should set the res on the 200K at so i get 3.5 (while running 3.3 in the bios)

[Fewture]

The undervolt is normal I think. Mine undervolted too. But if you mod it..whats the problem? ;)

[Asio]

i hope my board undervolts as im not happy with 232 3dstable 8/3/2 cas2. Prime can run untill 245 but dont even think of running ut2k4 then ...

On the 8rda rev1.1 i could run 230 with 2.9 (prolly 3v irl)

[bigZ]

directly below the DIMM slots is the vDIMM readout, that's correct :)

[STEvil]

Odd idea here... are all of us who have undervolting VDIMM running high +5v rails?

Yes for me.. how about you guys?

[Asio]

Just mesured from the 5V molex and got a 5.53 readout. 5.43 in mbm5.
IF i didnt have cooling on the Vdimm mosfet i would have mesured that to. I'le let u know one of these days.

mbm5 also tells me i have 3.45 and 12.45.

[ricjax99]

Just check mine I get 2.94V at 2.80V bios :confused:

[ricjax99]

+3.3V molex = 3.61V
+5V molex = 5.43V
+5V board = 5.34V
vdimm = 3.41V

Bios = 3.30V :slobber:

[funktional]

Just measured again and got 3.11V :confused:

Vdimm mod here I come ;)