New vDimm=vIO mod for NF7-S v2

[cartmanea]

I made a small alteration to the vdimm=vio mod so I thought I would share it. Basically, instead of connecting the mod wire to a pin on the dimm slot, I connect it to the vdimm capacitors.

This makes it much easier/safer to do the soldering, and it also more evenly distributes the voltage. There are many more than just one vdd pin on the slots, so connecting a wire to one of those pins makes all the current have to go through that one trace. This is what causes a vdimm droop that some people have noticed and gotten around by connecting to multiple slots.

I have connected to 3 of the 4 possible capacitors, the fourth I did not because it was surrounded by traces. Probably two or maybe even one would be plenty. The main one that you should do is the one next to the vdimm mosfet (lowest one in the picture).

Also, probably 22-24 Ga wire would work best, I used 20Ga because it was all that was available at the time.

Here's a picture of the mod:


Please post your thoughts/questions and if you've seen or done this method before. Thanks!

[LorD_Kvadd]

Nope, havn't seen exactly that one before but a very similar one made by I think it was STEvil.

Any improvements over the ordinary vio=vdimm mod? I mean as stability in memtest or anything?

Nice soldering

[cartmanea]

I haven't done the other method, but people reported voltage droop with it. This method is better because you are delivering the voltage to the capacitors before it goes to each slot (and multiple pins on each slot) instead of making all the current go through the trace of one dimm pin.

[STEvil]

The very bottom wire is doing the same that mine does, except I use 2 to the big fat trace you can see under the PCB there.

Either way is good, lets the caps do some work and doesnt put as much load on the traces

[cartmanea]

So you uncovered the trace and soldered directly to it? I feel more comfortable soldering to the caps I think, but they always do work since they are all on the vDimm bus.

[Antiloop]

Hi Everyone;
cartmanea i think this mod give all slots same voltage, am ı right? (sory formy bad eng) I have 2x512 a-data and ı want to give them extra mod together, is this mod suitable for me?

Thanx

[cartmanea]

Yep, it gives the full 3.3v rail voltage to all 3 slots. It will work well for you, just be sure your ram can handle 3.3v

[Antiloop]

Hi;
Thank you Cartmanea, I will apply ıt to my nf7-s, and ı'll write the results, btw can give us some bench results?

[CaTalyst.X]

So you uncovered the trace and soldered directly to it? I feel more comfortable soldering to the caps I think, but they always do work since they are all on the vDimm bus.

Yeah but by soldering to each one you take some strain off the traces.

-CaT

[13oost]

out of the grave it comes... =/

im doing this mod in a few days... which would be better, solid wire or stranded?

which would be better... doing dirty punk's mod on all 3 dimm's or doing it the way that it is mentioned in the first post

[cartmanea]

I think my method is safer and distributes the current to the 3 slots better. There are more than one vdd pin in each slot, so just connecting to one pin makes all the current for the entire dimm feed back through that small trace.

About 24Ga stranded wire is better since stranded wire will have lower resistance than solid. It also will make a more solid connection when you solder it to the pins.

[13oost]

i guess this 18ga solid core is headed back to radio shack in the morning...

but still, if you applied the dirty punk mod to all 3 slots, instead of just the 1st slot, it should take about all the stress off the traces, but by going your method, the votage will be "cleaner"

[cartmanea]

The Dirty Punk mod connects to one pin on the dimm right? So even if you connect to all 3 dimm slots, the current for each slot is still having to feed back through that pins tiny trace to get onto the main dimm bus and distribute to the other pins. My mod doesn't necessarily provide "cleaner" voltage, but it is applied to the main vdimm bus which distributes the current more evenly and reduces the potential voltage drop to each pin.

[13oost]

no, no... not in series, lol... you would do the same as you did, except to 3 dimm slots... there is 3, 3.3v lines, one for each vdimm.... or maybe you could take all 3 lines and connect them, and then split them agian before you connect them to the vdimm (more current, yes/no, maybe that extra solder would make it worse), so theyre essentially in parallel, like yours are, except on the 3 dimm slots

EDIT, im not going agianst what you are saying, its just an idea, ive seen a few pics where people have labeled the different vtt points, etc, and it had the vdimm on there, and with CaT's comment about having all 3 connected, i got the idea of connecting each dimm with the 3, 3.3v rails with dirty punk's mod.... i really dont want to go out on a limb, especially kill my board...

the board should be able to handle 3.3v on the traces anyway, yes the 3.3v rail may be more stable and less load on the traces "through my theory" with all 3 dimm slots getting voltage straight from the 3.3v rail, but with your mod the voltage would be cleaner

if i do kill the board, i guess ill be picking up the DFI Infinity Ultra B Refurb for 55 off newegg (cant afford a new NF7-s, its 89, and there isnt a new UltraB)

[STEvil]

if you connected to one single pin on each slot you will be feeding through small traces still and it has to backfeed from that pin to each of the other VDIMM locations.

Its better than the standard dirtypunk method, but still not the best way to go.

Either go to the back of the VDIMM mosfet, or go to 3 capacitors. solid or stranded will both work fine.

[13oost]

which is better.... i figured the solid would carry a better current, but i could be wrong..

i have 18gague solid strand

also doing the 3.3v vsense mod.... so should i return for the stranded....?

i have to go back to get some resistors and a VR

n33d to know by morning so i can make a quick detour to Radio Shack before my Electronic Imaging class

[STEvil]

youre wire will work fine, and the thicker the better.

[cartmanea]

18Ga solid isn't going to solder to the cap pins too well. I like 24Ga stranded because you can actually wrap it around the pin before soldering and it makes a much better/lower resistance connection. Remember, current travels along the outside of wires, so stranded wire will offer a lot lower resistance than large single core, especially at the connection points.

[The Coolest]

Hi all, I guess I'd post my results from this mod and give this thread a deserved bump.
I have half-fried my board's RAM power supply and only got 2.3-2.45v no matter what I have set in the BIOS, so I decided to do this mod.
I just finished putting my system back together and running it through about an hour of memtest. I only soldered +3.3v to the big cap on the bottom of the picture, using a wire from PSU's ATX connector, there is no need for any of the other caps basically, as the power reaches them from the main cap anyway.
Now my VDimm is the same as my VIO, which is around 3.45v, slightly high, but way better than 2.3v.
Thanks a lot!!

Now I have a question, regarding VTT, what was your expirience with how well does it track with this mod? Someone just told me it can track up to 2.9v, which basically results in a 1.45v VTT.

[<Wouter>]

Hi all, I guess I'd post my results from this mod and give this thread a deserved bump.
I have half-fried my board's RAM power supply and only got 2.3-2.45v no matter what I have set in the BIOS, so I decided to do this mod.
I just finished putting my system back together and running it through about an hour of memtest. I only soldered +3.3v to the big cap on the bottom of the picture, using a wire from PSU's ATX connector, there is no need for any of the other caps basically, as the power reaches them from the main cap anyway.
Now my VDimm is the same as my VIO, which is around 3.45v, slightly high, but way better than 2.3v.
Thanks a lot!!

Now I have a question, regarding VTT, what was your expirience with how well does it track with this mod? Someone just told me it can track up to 2.9v, which basically results in a 1.45v VTT.

I'm glad to hear that you sorted out your vdimm problems.

Ontopic: I'll try these mods tomorrow.

[cartmanea]

My Vtt tracked perfectly with my vdimm, and I took it to 3.4v. In fact, my Vtt was slightly higher than 1/2 vdimm.

Also, the reason I did more wire connections is because there some resistance at the solder points, so multiple solder points reduces the current though each.

[The Coolest]

What PCB version is your PCB version? Mine is 0.52.
MBM5 reports the same exact voltage to the vDimm as my vIO.
The current by itself is probably pretty high since RAM can eat around 25W and at 3.4v that translates into 7.35As, but as the voltage is pretty low this is negligble if you use a PSU wire, if you want to make sure that there won't be any risk of frying the wires, just use two paralel wires, it'll split the current in two so it'll be twice as low through each cable. I don't know what kind of resistance there can be at a solder joint if its done right, if there is resistance, its not greater than the one you'd get when the voltage is coming from the MOSFET. It's probably negligble.

[KODE]

My Vtt tracked perfectly with cartmanea's mod, with MBFAQ I had to do the Vtt cut-trace mod.

[Rookie]

guys any links with pics on the vtt/vbt mod? all the links i've found are dead.

i just did the vdd and vdimm as per mbfaq site. that vdimm mod was easier for me to do(i'm a first time modder ) also the vdroop mod, not the pencil one but the one with capacitors. i read the thread in here but there were no pics.

from reading on this mod, if i did the mod this way as pictured i probably wouldn't need the vtt vmod. but since i'm new i want to take it slow and do the vtt vmod and then measure it.

thanks


***edit*** finally found a link on malvescorner. i have it booked marked under .com but now its under .net

now i need instructions and a picture on how to do this vdroop mod

[cartmanea]

This mod is very easy and no need to do the Vtt mod, mine tracked perfectly up to 3.4vDimm. Also, you don't have to do all 3 wires, it just helps reduce resistance between the ATX connector and Dimm slots; reduces current though each solder point.