Increase VDIMM om NF7-S 2.0

[Aviator747]

I want to know what is a safe everyday voltage for the VDIMM. I am running a NF7-S 2.0 board with Tictac's D22A 1BK R2 bios. Now I am able to run my memory at a higher speed 220 Mhz. Now according to that that bios my VDIMM is 3.01v when set to 2.9v. I am able to boot into windows at up too 245 Mhz. But, IE crashes on my when I start it.

My memory is one single stick of Twinmos PC3200 BH5 512M. My timmings are 2-2-2-11.

I'm running a 2500+ Mobile at 2v & my VDD is set to 1.8v

Also would I benefit any from a VDD mod?

[{PMS}fishy]

A VDD mod may or may not help. Some say that it does not on the 2.0v MBs. It helped me a little bit, but I also added better cooling, so it could have been a bit of both.

As far as V-Dimm goes, BH5 loves voltage. The most you can run modded is 0.1v less than your 3.3v rail, so you may have to mod that too. I run 3.2v to my memory and others run 3.3 and upto 3.5 for the BH5 chips.

If you need to find the volt mods, check out this site.

www.motherboardfaqs.com

[Aviator747]

I read that someone doesn't bother with the resistors for the VDIMM mod. They just take a wire straight from the smd chip & connect it directly to ground. Is this true?

According to the latest version of MBM5 my 3.3 is sitting at 3.26. So I would get a voltage of 3.16, correct?

For my power supply I am using a Antec True Power 480. To modify the 3.3 rail it involves tweaking the pots inside of the PSU, right? If I remember right memory is the only thing that runs off of the 3.3 line eh?

Thanks for the info. Man this stuff is addictive. :D

[{PMS}fishy]

Its possible to do it that way, but I wouldn't. In case you ever need to turn it down.

You are correct in assuming a voltage of about 3.16v

The TPs do not have adjustable pots inside of them. You have to snip the sense wire for the 3.3v rail and add a 10k (I think) resistor to it.

DON'T GO MY 10K figure. That might be wrong.

Search XS I think the mod for the TPs is on there.

[Aviator747]

Is it just the memory that feeds off of the 3.3v rail? I forget off hand.

XS? I'm not familiar with that.

[{PMS}fishy]

http://www.xtremesystems.org/forums/

[Hell-Fire -XS-]

Yes, the memory on the NF7 boards is dependant on the 3.3v power rail of the psu.

I wouldnt do the Vdimm they way you mentioned above by diretly connecting the SMD to a ground.

Better to sodler a 1K VR's middle leg to the right end of the resistor and another leg of the VR to a ground.

If you want more than 3v (which you get with 2.9v when set in the bios), you would need to do the 3.3v rail mod for your psu.

[Aviator747]

So what is the real harm to grounding out the SMD resistor straight to ground instead of tying a resistor to it. Besides the fact that if I want to turn it down later I can't. If I dod want to turn it down I would only have to lift the ground side of the wire to put a VR in. Right now I want to see how far I can push my FSB with my current full rail voltage. Hell-Fire -XS-, what voltage are you putting to your ram?

Also what gauge wire do you guys use? I assume wire wrap wire is too small of a gauge?

[Hell-Fire -XS-]

Originally posted by Aviator747
So what is the real harm to grounding out the SMD resistor straight to ground instead of tying a resistor to it. Besides the fact that if I want to turn it down later I can't. If I dod want to turn it down I would only have to lift the ground side of the wire to put a VR in. Right now I want to see how far I can push my FSB with my current full rail voltage. Hell-Fire -XS-, what voltage are you putting to your ram?

Also what gauge wire do you guys use? I assume wire wrap wire is too small of a gauge?

If what I think you mean by grounding out the SMD, then you would end up with a zero resistance across that resistor, or a short circuit.

I run 3.25v-3.35v daily. I run as high as 3.6v when benching.

I use anything from 18-24 gauge. You can even use the wires that are part of a hard drive cable if you like. The current we are dealing with is so small that the wire does not have to be a thick one with lots of surface area.

[Aviator747]

Yes, it is basically shorting that resistor to ground. It would be like taking the VR & turning it all the way down to 0 ohms, no resistance. So when the chip looks to see how much power it is putting out. It goes Hmmmm, I'm not putting out any power & gives the whole rail.

picky: http://www.motherboardfaqs.com/Abit_nForce2/images/vdimm_mod/solder_points.jpg

Cool, so I can use my 30 gauge wire wrap wire then.

So you never bothered with the VDD mod then?

[Hell-Fire -XS-]

If you are speaking to me, wouldnt do a Vdimm on the NF7 without doing the Vdd.

I dont think it gives the whole rail with a zero resistance. When you short out that SMD its the same as jsut removing it and bridging the solder pads together. That would give you strictly bios level settings I believe...not the rull rail.

The full rail is given when you remove the fixed resistor and solder a VR between the right solder pad and the FET leg.

[Aviator747]

Yes, Hell-Fire -XS- I was talking to you. :) So you are saying that the VDD is a benefit when done with the VDIMM mod? What are you running your VDD at?

I'll have to investigate the full rail thing some moe for my current setup.

[Hell-Fire -XS-]

I have my Vdd setup so that I get this actual voltage per setting in the bios:

Vdd: BIOS Actual
1.4 1.67
1.5 1.83
1.6 1.94
1.7 2.00

I run it 24/7 between the 1.4 and 1.6 setting based on what I am doing. I run it at the 1.7 setting when benching.

Yes, the Vdd coupled with the Vdimm certainly helps with this board. I would say that after modding a good 12 of the things that a solid 80% of them benefited form doing both mods versus just the Vdimm mod.

I just shipped one out to a member of XtremeSystems.org this morning. Here are the results:

Before Vdimm: Max fsb --> 228
After Vdimm: Max fsb --> 241
After Vdimm & Vdd: Max fsb --> 260


Keep in mind that I didnt have time to do testing with memtest86 or run 3DMark as I had it to get it back out to him as I was running behind on my modding for people. BUT, you have to admit that even a post at 260 with CH5 ddr is pretty damn good. Taking that into account I am wagering that if he benches with a 3.45Vdimm and 2Vdd, he should get stable benchies at 255 or so fsb. But that is just a guess obviously.

I also modded his psu to supply 3.75v on the 3.3v power rail.

[Aviator747]

Impressive! Is this with stock cooling on the NB & an added HS to the SB?

So you just play around with the sense lines on your PSU, eh? And then you added those ground shunts that I seen in your pic's.

Does running the 3.3 rail at 3.75 have any negative effect to anything else that is running off of that rail? Seeing the memory is dialed down by the VR's?

Like I stared in my post earlier I can boot into windows at an FSB of 245 with my Twinmos BH5. So I might get some fairly interesting results with the mods.

[Hell-Fire -XS-]

Originally posted by Aviator747
Impressive! Is this with stock cooling on the NB & an added HS to the SB?

So you just play around with the sense lines on your PSU, eh? And then you added those ground shunts that I seen in your pic's.

Does running the 3.3 rail at 3.75 have any negative effect to anything else that is running off of that rail? Seeing the memory is dialed down by the VR's?

Like I stared in my post earlier I can boot into windows at an FSB of 245 with my Twinmos BH5. So I might get some fairly interesting results with the mods.

No, I changed out the NB cooling for sure. Got the Swiftech MCX159-A block for it. Didnt add a thing to the SB, but plan to when I have the time.

Yes on the sense lines. Most psu's have atleast one sense line for the 3.3v rail...sometimes sense lines for the 5v and 12v rails as well.

No, running at 3.75v hasnt seemed to affect a thing. I am not sure off the top of my head what else is powered by that rail.

Yes, Vdimm is controlled by the VR along with the bios. You set the VR to whatever Voltage you want when set to max bios setting. Then to lower it you choose a different setting in the bios.

If you can boot into windows at 245 unmodded, you should see nice results after mods I would think.

[Milkman]

I figured I would find you in a volt mod post, how's it going Hell-fire? I haven't talked to ya in awhile. Still wanna have you fix that in-socket thermistor on my Nf7-s and volt mod both.

-Milkman(Milkmover) Aka Mike