8RDA/+ memory mod?

VBT didnt make my bios show the correct voltage.

And I didnt get any higher overclock with it.

I havent tested the votlages like bowman, but I wasnt getting much drop under load before VBT so I dont think there would ahve been a big change.

I used a 500ohm VR BTW.

I think VBT is used to terminate the VDIMM bus so a PC could be automatically configured to work with only 1, 2, or 3 slots of RAM.

To test this, use 1 slot and try setting VDIMM in BIOS to +2.50V and adjust VR resistor to get +3.4V. I think that a PC won't boot due to 36% discrepancy between +1.25V VBTout and the expected +1.70V (1/2 of VDIMM)

Vbt needs to be 1/2 of VDIMM.

So do i need to do the VBT mod?

i recommend.

Why are they using both sides of the VR on the mods over at VR Zone?
Edit
It doesn't look like they are going to both sides of the VR, but it doesn't say exactly where the other side of the brown wire was attached. Can anyone verify the exact location of the 2 brown wires coming of the Q34 Mosfet?
Thanks in advance
Nate

Looks like they grounded the other side out... which I asked about a month or so ago and nobody had any reason as to actually why someone would do that. ;)

The Mosfet leg is ground. I doubt that they went from a ground to a ground.

very nice m8 thank you :)

Ok so lemme get this straight which of those wires is a ground?? the one soldered onto the trace right?

MickeyMouse, I was talking about the 2 brown wires that they used in the picture. Can you or anyone tell me exactly where they go and what they are for would be helpful also.

Thanks
Nate

They are not connected to the pot from what i can see

Quote:

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Originally posted by Nohto
Why are they using both sides of the VR on the mods over at VR Zone?
Edit
It doesn't look like they are going to both sides of the VR, but it doesn't say exactly where the other side of the brown wire was attached. Can anyone verify the exact location of the 2 brown wires coming of the Q34 Mosfet?
Thanks in advance
Nate

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I know I stated that earlier.

so do i have to expose the trace to solder that wire on???

Yes I do believe so. If you go here they have better pictures of the mods.

Ok so lemme get this straight which wire is ground. On a pot like the one's at the shac how would i go from the dial side down. Would it still go Blue white.

Correct me if i am wrong but isn't this how those corresponding wires in that pic should go if i were to use a pot like this
http://mollyockett.com/potentiometer.gif

I did not connect the brown wires when I did the mod and it works fine for me. I really don't know what they are accomplishing and I haven't heard anyone give a reason as to why you would do it so I don't. :D

And you can use either of those pluses along with the negative if you do it like I did.

ok guys from what i am told ..and i havent tried to confirm this because mine work...
but the brown wires are to ground and it is suposed to make for a non varying resitance.the vr resistors sometimes change slightly and that is surpossed to stop that.

but i have no reason to try to find out LOL:D

http://www2.arnes.si/~mlivak/8rda/vddr%20mod.JPG

I've made both mods vddr in vbt, I uses 5k pots and did the same as vr-zone. I don't know what are the values of both trimmers because when I set them to 500ohm and started computer I only got FF on diag disp. So I take multimeter and measured the voltages. They were both way off, so I first started turning vbt pot to 1.45V (I had 2.9V set in bios) when I set that, I started turning vddr pot. and check for vddr voltages with multimeter. When I find 2.9V I restarted and went into bios (everything was working obviosly) and change vdimm to 2.77V. Then back to post up and press pause, to stay there. Then I again started turning the pots and set vbt to 1.55V and vddr to 3.1V. I wanted 3.1 at 2.77V to have room left. Then I went to bios again and set vdimm to 2.9V, restart and check the voltages, vbt was 1.62 and vddr was 3.23V just as I want them. I didn't try anything further but I definetly could. I'll be playing with 3.2+ to see if Kingstons show any imporvement past 3.2V. My BW is in overclocking section btw.-

Just done the mod :i did only the Vdimm mod now.. not VBT
I've set a trimmer to 220omh..
mobo booted fine while setting 2.9 in bios..
i've tried to mesure with multimiter but i always read 3.25 even setting 2-5 in bios

if i set 2.9 or 2.77 mobo doesn't load windows

i'll try to work it out

oh yes :D
i work it out 2 minutes later..
i forgot to post it !

i read 220 ohm in another mod guide..
so i set it before soldering
then i lowered the pot while measuring with multimeter and set it to 3.2v max

so VBT isn't worthy right?

Hi guys :)

Can someone tell me , where i can get proper vddr and vbt
with multimetr ? I'll be very glad to see some pics where
these points are selected.

ps sorry , but my english as not good as i want and
it's so difficult to me to read all these posts :(

I did the vdd mod, and im wondering if i should do the vmem. After the vdd mod was done i am able to run at 230(460fsb) but cant get any higher with any more voltage which leads me to belive the ram needs more now. Can anyone confirm this for me?

Quote:

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Originally posted by Shroomalistic
I did the vdd mod, and im wondering if i should do the vmem. After the vdd mod was done i am able to run at 230(460fsb) but cant get any higher with any more voltage which leads me to belive the ram needs more now. Can anyone confirm this for me?

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Try to run you ram higher then your fsb to see if it really is holding you back. If it won't run any higher, then you might need the vdimm mod.

I want to try this but I think I lack the skills. My 8rda is undervolting down to about 2.83-2.84V when I have it set at 2.9V. It this normal? The vdd is set at 1.9V. I can get it too about 227-228mhz though somehow a month ago i got it to 232mhz and benchmarked a few things.