DFI NF4 Ultra-D vdimm mod: come inside.

[Malves]

Posted at www.hardwareasylum.com. Here's the thread. Have fun!

[mcnbns]

Details? Why is this better than just changing it through the BIOS? Thanks!

[Malves]

Just giving ppl another way to up vdimm using 3.3v rail. It's just the old and trustworthy vdimm mod. With a modded PSU, you can get stable vdimm over the default in BIOS when using 3.3v rail.

There is the jumper trick to make more options available in the BIOS. But what if you forget about that and select a vdimm that's higher than your rail? You can kiss your board goodbye
You can setup the board to use 5v rail, but you get a hot FET that just brings instability.
A few members reported having issues when using the 5v rail. User or not user error, I don't care. Here's the mod and I hope it helps ppl out there.

IMO, the vdimm mod using 3.3v rail will give you cleaner voltage.

[persivore]

Good work on the Vmod bro

Malves and myself have been thinking, this mod could possibly help people who are experiencing cold boot problems. The problem with cold boots has been found to be the fact that the board feeds the RAM with ~2.6v before the BIOS is loaded. By doing this mod, it should be possible to set the Vdimm that the board boots with, using the variable resistor, so that the voltage the Vdimm regulator gives out is set by the user, and not what the BIOS is being told to give out. You will need to set the voltage in BIOS to the minimum possible (so that the voltage doesn't suddenly rise when the BIOS is loaded), and use the variable resistor to raise the voltage to the required level.

Does anyone want to test this theory?

[stealth17]

Good work on the Vmod bro

Malves and myself have been thinking, this mod could possibly help people who are experiencing cold boot problems. The problem with cold boots has been found to be the fact that the board feeds the RAM with ~2.6v before the BIOS is loaded. By doing this mod, it should be possible to set the Vdimm that the board boots with, using the variable resistor, so that the voltage the Vdimm regulator gives out is set by the user, and not what the BIOS is being told to give out. You will need to set the voltage in BIOS to the minimum possible (so that the voltage doesn't suddenly rise when the BIOS is loaded), and use the variable resistor to raise the voltage to the required level.

Does anyone want to test this theory?

lmfao

http://www.xtremesystems.org/forums/...293#post916293

i still say the utt-ch just sucks for high voltage long-term

[timpanogos]

Please elaborate on this vdimm modification..

1. say you only have 3.3 volts on your 3.3 volt line. This mod will allow you to get up to say – 4.0 volts from that 3.3 source?

2. I just did a sense line mod to my 3.3 I set it to 3.5, and have bios set at 3.3 – this actually gives me a DMM measured 3.38 on the memory. Are you saying that if I set my bios to say 3.6, with only 3.5 set on my 3.3 line, this would fry mobo components? Seems this would simply peak out at 3.5, no matter what you set the bios to above that? Note, that setting it to 3.4 may exceed that actual 3.5 volts that are currently set (i.e. .08 higher than 3.3 setting).

[mcnbns]

Just giving ppl another way to up vdimm using 3.3v rail. It's just the old and trustworthy vdimm mod. With a modded PSU, you can get stable vdimm over the default in BIOS when using 3.3v rail.

There is the jumper trick to make more options available in the BIOS. But what if you forget about that and select a vdimm that's higher than your rail? You can kiss your board goodbye
You can setup the board to use 5v rail, but you get a hot FET that just brings instability.
A few members reported having issues when using the 5v rail. User or not user error, I don't care. Here's the mod and I hope it helps ppl out there.

IMO, the vdimm mod using 3.3v rail will give you cleaner voltage.

Sounds good.

I'm going to stick with the 5V jumper method, but I'm glad someone gave people who want really stable VDIMM a mod, finally.

[Malves]

Please elaborate on this vdimm modification.

1. No.

2. I read it would damage the board.

[timpanogos]

wow, thanks for the safety tip there Malves! I'll be sure and watch that closely if I ever go to set my bios to 3.4. Any idea what a "safe" rail voltage would be above your current/desired vdimm?

p.s.

Also wondering then, if one did have like say 3.7 volts on the rail, and wanted to run at say 3.5 vdimm, with the mobo mod, you may want to set your bios to say 3.6 and then adjust the mod's pot for the desired 3.5 exact?

Like even now, the overvolting of my rail seems to cause .08 volts more than the bios setting of 3.3 to actually be applied. Your mod would/could limit this further to the exact 3.3 -- is this right?

The above assumes the bios controls that chip you are further moding.

[Malves]

No, you always select less than the value you want, and then trim to it.

Yes, with a vdimm mod you have total control over the voltage.

[timpanogos]

No, you always select less than the value you want, and then trim to it.

but ... that is what you read could blow the board right ?? (rail less than bios setting) .. For example, say I want 3.4 volts .. so safety says, set your rail to 3.3, set your bios to 3.4 and then tweak the rail until you have 3.4 on your memory.

Sorry for all the bother, just saw your name on the hellfire sense mod thread (and ensuing mess) .. and know by that read, that you know what the heck is up.

Thanks!!

Chad

[felinusz]

Malves, will this mod work when on the 5V VDIMM jumper?


I would use this in tandem with the 5V jumper, to fine-tune VDIMM.

As it is, my board overvolts VDIMM by ~0.8V-0.9V, so 3.78V and 3.89V are the only two higher VDIMM selections I can make. I want to test between 3.8-3.85V :p

[Malves]

I didn't test it with 5v rail. I'll do that tomorrow and let you know.

[dippyskoodlez]

I didn't test it with 5v rail. I'll do that tomorrow and let you know.

so if your 3.3v line is at 3.6, you can select up to 3.5?

[Malves]

Trying to find where I read about board being damaged if selecting vdimm in BIOS > 3.3v rail. Can't find it, thou.

Please, you guys have to understand this vdimm mod works just like any other vdimm mod for boards that use a 3.3v rail for RAM. All you have to do is to use the board set at 3.3v and a modded PSU. Just like we used to do.

You can use the jumper trick posted in the AMD section with a modded psu. But a vdimm mod will give you total control over voltage adjustments.

Tomorrow I'll be checking the mod with the 5v rail to see if vdimm over 4v is possible for the kamikazes out there.

[EMC2]

You may have to add a pot to the 1st stage control Malves to get much over 4V... opposite side of the dual amp

Peace

[celemine1Gig]

Interestingly enough, it seems to be the exact same voltage regulation circuit like on the DFI LP NF3.

[Barr3l Rid3r]

how can I measure vcore and vchipset in that board?

[G H Z]

Malves have you or anyone seen the NF3 939 DFI? I want a vio mod for it also.

[Malves]

Nope, haven't seen that board yet, bro. I don't like vio mods, sorry.

Just to add, VTT tracks just fine on this board. VTT check is the top leg on that same mosfet (where you check vdimm) in that pic.

[EMC2]

Barr3l --- Look here for all V measurement points

Just to add, VTT tracks just fine on this board. VTT check is the top leg on that same mosfet (where you check vdimm) in that pic.

Depends... put in 2x512 with >250Mhz Memclock and run Memtest T8 with VTT instrumented bro

Peace

[Malves]

Hmmm...didn't know that. I don't have a cpu to run that test.

[timpanogos]

"just to add, VTT tracks just fine on this board. Vtt check ..."
"depends ... put in 2x512 with ..."

what language are you guys speaking?

Can you tanslate to gumbie?

what is Vtt? and what does it have to do with vdimm and chipset voltage, and 250memclock with 2X512 and some processor needed?

boy am I lost or what?

Chad

[stealth17]

"just to add, VTT tracks just fine on this board. Vtt check ..."
"depends ... put in 2x512 with ..."

what language are you guys speaking?

Can you tanslate to gumbie?

what is Vtt? and what does it have to do with vdimm and chipset voltage, and 250memclock with 2X512 and some processor needed?

boy am I lost or what?

Chad

vtt is half of vdimm. its very important and if it gets too high or too low of the vdimm then stuff wount work right. some boards need a vmod to make the vtt right while the dfi nf4 seems to keep it okay by itself. what EMC2 is saying is that if you run 2x512mb ram at >250mhz and then run memtest #8 then the vtt might go off a bit. i think thats what he is saying

[timpanogos]

Interesting, and I assume the bios has some effect on this tcc as well as vdimm control .. in as much as I have heard some saying that the 5-15/18/23 bios has left them super-pi unstable at previous oc's etc.

What are some of the symptoms that are seen on "other boards" that lead to the vmods? Are there certain ras/cas/drive strength etc. types of settings that corrolated with vtt problems (i.e. some vtt mod allowed for setting x to be tightened to y)

Thanks!!

Chad