trick to get more stable vdimm on the dfi nf4!

[saaya]

big thx to bigtoe again








UPDATE:
pretty late yeah, but better than never
here are results from my rig (dfi nf4 fortron 350W) using the trick
i have the 3.3v rail set to 3.51v here is the vdim i meassured chosing different vdimm options in bios

<TABLE BORDER WIDTH=600><TR><TD>vdimm set in bios</TD><TD>vdimm idle</TD><TD>vdimm load</TD><TD>3.3v rail idle </TD><TD>3.3v rail load</TD><TR><TD>3.0v</TD><TD>3.09v</TD><TD>3.09v</TD><TD>3.51v</TD><TD>3.48v</TD><TR><TD>3.1v</TD><TD>3.20v</TD><TD>3.20v</TD><TD>3.51v</TD><TD>3.47v</TD><TR><TD>3.2v</TD><TD>3.31v</TD><TD>3.30v</TD><TD>3.51v</TD><TD>3.47v</TD><TR><TD>3.3v</TD><TD>3.38v</TD><TD>3.32v</TD><TD>3.50v</TD><TD>3.47v</TD></table>

so it looks like the dfi nf4 overvolts vdimm by almost 0.10v
this means you should set your 3.3v rail to 3.5v+ and select only up to 3.2v in bios. this should result in a pretty stable 3.3v vdimm voltage. to make sure you get a really nice and clean 3.3v vdimm id suggest to set your 3.3v rail to 3.6v. for vdimm above 3.3v i suggest you use the 5v vdimm feed and get a 20 to 24pin psu adapter if your on a 20pin psu and dont want to upgrade. to everybody who uses this trick, keep in mind that sata hdds and other components of the system use this rail as wel and it might make them unstable or kill them over time
never heard of it, but theres always a risk you should be aware of

[elh4jj4j]

nice , i will try it

[mcnbns]

Is that red thing on the middle diagram another jumper?

Do you have to go about it the same way as enabling the 4V VDIMM option?

Thanks!

[AMD-me]

nice, :thumbsup:

[ZhaoYun]

I'll give it a shot.

[P_1]

Is that red thing on the middle diagram another jumper?

Do you have to go about it the same way as enabling the 4V VDIMM option?

Thanks!

yes its another jumper

[Magnj]

sweet. How high will the Powerstream 520 go on the 3.3 rail?

[_Eduard_]

I thought this was already possible without changing the jumpers, so good information

[uwackme]

Im not all the way up yet, but my Powerstream does 3.5V on the 3.3V rail....on NForce2, the NB chip uses Vdd and ALSO uses 3.3Vrail as power sources. So you get higher max OC with 3.3V rail UP, even if you dont needed it for Vdimm usage.

[Bennah]

Thanks Bigtoe

[perithimus]

I will definitely have to try that. Just hoping my psu will hold up. I think it will.

[s7e9h3n]

This is nice for those of us who have a Zippy and use the DFI. But I don't see myself running my 3.3 rail @ 3.9 so I can use my BH-5 @ 275, 3.8V.

[[_Silence_]]

Can i use it with a 20pin Enermax 460watts and a 20pin to 24pin adapter?

[craig588]

It's not reccomended.

[mcnbns]

sweet. How high will the Powerstream 520 go on the 3.3 rail?

3.8V is what it says on the box here.

[[_Silence_]]

It's not reccomended.

My Enermax is fully moded, so it would be better than running from 5v right?

[[_Silence_]]

My Enermax is fully moded, so it would be better than running from 5v right?

Just tested with my Enermax 460watts and 24pin adapter and I dont advise to do it. Very unstable Vdimm, eg: 3.3 rail @ 3.6v and 3.4v in bios gave me Vdimm from 3.45 to 3.35, to much variation :S
So really no go with 20pin PSU :S

[bachus_anonym]

Just tested with my Enermax 460watts and 24pin adapter and I dont advise to do it. Very unstable Vdimm, eg: 3.3 rail @ 3.6v and 3.4v in bios gave me Vdimm from 3.45 to 3.35, to much variation :S
So really no go with 20pin PSU :S

It's most likely not because your PSU is 20-pin... Either raise your rail to 3.7v (measured with DMM) or lower vdimm in BIOS. Give it .3v overhead as see what if it helps...

[Magnj]

this is sweet.I dont have a jumper though...gonna have to get one from school next week , would one from a HD work. And can anyone direct me to a link on how to adjust OCZ Voltage?

[saaya]

Is that red thing on the middle diagram another jumper?

Do you have to go about it the same way as enabling the 4V VDIMM option?

Thanks!

yeah, just use a spare jumper and move the "jumper block" down one row

I thought this was already possible without changing the jumpers, so good information

no, the bios wont let you use vdimm options above 3.2v without this trick

sweet. How high will the Powerstream 520 go on the 3.3 rail?

im sure it has been posted somewhere on the forum, prolly when ocz released the psu... i think 3.8v... maybe more

Can i use it with a 20pin Enermax 460watts and a 20pin to 24pin adapter?

i dont see why it shouldnt work...
if you have a 20 to 24 pin adapter you can use the 5v feed for vdimm as well, but i wouldnt recommend it unless you go for 3.6v+ and have some airflow on the mosfet/heatsink on the top right corner of the board.

It's not reccomended.

what isnt recommended?

Just tested with my Enermax 460watts and 24pin adapter and I dont advise to do it. Very unstable Vdimm, eg: 3.3 rail @ 3.6v and 3.4v in bios gave me Vdimm from 3.45 to 3.35, to much variation :S
So really no go with 20pin PSU :S

did you use the trick or did you use the 5v feed?
how did you meassure vdimm?

this is sweet.I dont have a jumper though...gonna have to get one from school next week , would one from a HD work. And can anyone direct me to a link on how to adjust OCZ Voltage?

the powerstream line has small pots on the back of the psu to increase the rails, the modstream series doesnt have pots at all, even if you open the psu...

the only way to icnrease the 3.3v rail on the modstream would be to do the 3.3v sense wire mod

[craig588]

what isnt recommended?

Using a 20 pin PSU with the DFI NF4 mobo.

[saaya]

its not? i heard it works fine though... the only extra lines used are the 5v lines if you use the 5v vdimm feed afaik. but im not sure...

they also recommend a 400W+ psu

im using a 350W 20 pin psu and the board runs great and ocs great...

[craig588]

There is one extra 12V, 5V and 3.3V line. (And a ground for some reason but there is no problem with the number of grounding lines on a 20 pin ATX plug)

[saaya]

yeah i know, but from what i can see only the extra 5v is getting used for the 5v vdimm feed, the other ones are just hooked up with the other 12v and 3.3v lines of the mobo...

thats why a 20pin psu works fine, at least with the dfi board, unless you use the 5v feed

[Wingz]

just to make sure i understand this...

1. change the jumpers as shown in the middle picture

2. you will then only be able to select 3.2v in the bios.

3. increase the voltage on psu's 3.3+ line and the vdimm will then increase as well

just wondering the "mofsets and heatsinks that will stay cool" are they the ones located on the top right of the board? and also how do you know what vdimm voltage you are on when adjusting the 3.3+ line.

Thanks.