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Bump for this mod.
I'm about to get this board & wanna see if there's a Vdimm mod for the board or not.
Couldn't live with anything less than 3.3Vdimm as I'm poor & don't have high OCing memory other than my beloved BH5's...
Waiting anxiously for your results Hell-Fire...
Cheers,
Minnyboy
Ok...think I got her figured out.
Will tidy it up and post first thing tomorrow. ;)
Ok then.
I dont have a cpu to test with, so not sure if that is the cause of what I am experiencing, but I can now increase/decrease the Vdimm. The odd thing is that it will jump around quite a bit per adjustment. Still turning in the same direction the Vdimm can increase and decrease as well. It still steadily increases, but it may decrease by some millivolts while adjusting.
If anyone has any ideas about why that is, I am all ears.
Also, is 2.5v the default Vdimm for this board?
**EDIT**
So far the best way to do this mod, imho, is with the 3.3v = Vdimm method. The pots are getting pretty damn toasty during adjustment. I had the Vdimm up to 2.95v and the thing was almost to hot to hold.
On a better side of things, this board does not require a Vtt mod as it tracks Vdimm. I ran the Vdimm to 3.318v, and the Vtt tracked at 1.659v. ;)
Can you please post pics of the 3.3v=Vdimm mod?Quote:
Originally posted by Hell-Fire
Ok then.
I dont have a cpu to test with, so not sure if that is the cause of what I am experiencing, but I can now increase/decrease the Vdimm. The odd thing is that it will jump around quite a bit per adjustment. Still turning in the same direction the Vdimm can increase and decrease as well. It still steadily increases, but it may decrease by some millivolts while adjusting.
If anyone has any ideas about why that is, I am all ears.
Also, is 2.5v the default Vdimm for this board?
**EDIT**
So far the best way to do this mod, imho, is with the 3.3v = Vdimm method. The pots are getting pretty damn toasty during adjustment. I had the Vdimm up to 2.95v and the thing was almost to hot to hold.
On a better side of things, this board does not require a Vtt mod as it tracks Vdimm. I ran the Vdimm to 3.318v, and the Vtt tracked at 1.659v. ;)
Sure....I will post them in a bit.
Be aware that I dont have a cpu to test with, so I dont know if it will boot at that voltage. I hear some boards will read a high Vdimm, but OVP keeps it from posting until Vdimm falls to around 3.1v.
http://www4.ncsu.edu/~rwbradl2/Vmods..._3.3=Vdimm.jpg
http://www4.ncsu.edu/~rwbradl2/Vmods...dimm_Trace.jpg
http://www4.ncsu.edu/~rwbradl2/Vmods...mm_Circuit.jpg
Ive already done this mod, i connected 3.3v straight to the dimm slot, ive had no problem booting, vdimm is 3.35v. I cant test my ram because its such a crap overclocker, ive booted at 260mhz with 11,2,2,2 1t settings, i dont know what the aggresive timing is in bios, enabled i can only run cas2.5, but i get better results with it enabled and cas at 2.5 then disabled cas2.0, im going to sell it and get an abit kv8 pro, i really liked my last abit board and a lot of people seem to like kv8 pro.
Good to know that the board atleast posts with high Vdimm.
yeah but 3.3 is to much 3 volt would be fine
Put a resistor between 3.3v rail and the wire what is connected the memory slot... Use a trimmer and You can change the voltage.. Am I right? I guess so..
ahh ok i think i will try that
Excuse my vast levels of newbieness, but I have a few questions about this mod. First, is there any way to do this with it being a little less permanent than soldering the board? Also, does it feed 3.3v to the memory regardless of the BIOS setting?
Well bud it must be giving you a fit. You ask if vdimm was 2.5 default I believe this is right if the cmos has been cleared. I am not 100% shure on that.
To tell the Truth I have been waiting for DFI for awail to get there boards out for the 64s. It looks like this may be soon.
After the the ABIT dyed on me for the second time I give up on the KV8. Two times in a row with no reason is enough for me. ABIT sayes they are investigating the problem right now but if they dont give me a board soon & it hold up I will build with the DFIs for shure. Although the board ran very good till it died & I would have built with it.
It dont look like the MSI is going to make the cut either. DFI has surved me best anyway, I stop building with the ABIT boards after I bought a Lanparty with the socket A boards before,maybe they will get there boards avalible soon and I want have to worry with these ABITS or MSIs.
Just do your best & take what time it need. If it dont want to play ball I will make a FOLDING machine out of it & leave it at 200 bus, so it will be able to be stable.
Okay, I have used the 1 wire from the 3.3v line to the (+) side of the cap shown and I have 3.31v on the vdimm, and exactly half on for vtt, but it is not very stable.... What would be causing the instability?
It 3.3v to much for EB3700? Is that causing the instability?
If I put a variable resistor in series in between the 3.3v line and where I connected to the cap leg, would this controll the amount of voltage that it would recieve?
Maybe 3.0v - 3.1v is the magic number for EB3700? or is there is something else causing the instability..
It is weird I can use 3,2,2,8 timmings at 245mhz where before I could not even post with those timmings at 240mhz +, but it still unstable.. It actually locked up in windows and when I reset the system, the bios was also reset.. (that is the first time I have ever seen the bios reset) Is this an OVP circiut causing this?
Uhh, are you sure you have proper cooling on the chips?? Take off the heatspreaders cuz they are insulators.
Well, I had some 1/2 watt resistors laying around and will try to drop the voltage from the 3.3v line to the (+) side of a vdimm circuit cap.. I first just used straight wire, and was getting exactly what my 3.3v line was reading.. I then put some resistors between the 3.3v line and vdimm circuit and it shows only what I set the bios?
Is the resistors not able to handle the wattage?
What size of resistor should I be using to drop the 3.3v to 3.0 - 3.1v? 200K? or 500K? or 50K? or 20K?
Is 1/2 watt resistor enough?
Anyone have some ideas here?:toast:
Update: I do need a much bigger wattage variable resistor. Like 25watts or so..
Anyone know where to get a 25watt or bigger variable resistor?:D
Hell-Fire,
So pin # 19 controlls the vdimm voltage? or is this just output line?
What do you suspect should be done with Pin #19? Are you looking for a resistor etc.. in the circuit?
After doing the direct 3.3v mod, my system is unstable, so I'm guessing that it's too much vdimm for my EB3700... I tried a fan blowing directly over them, but no change... I hear that the OCZ Vdimm Booster works, so the vdimm mod should work just fine.
The black pcb is just a pain uhh....:D
I can see it now.
Pic of Intel MSI neo. ( no mods)
http://www.orifice.pwp.blueyonder.co.uk/burn6.JPG
Ouch..... I seen that earlier.. I hope that is not what happens....I will be sure not to leave my puter unattended..:D
Hellfire, use the 3rd leg of the pot to ground it, that should help stabilize vdimm, the part about it getting toasty you will have to figure out, looks like mobo manufacturers are getting smarter, all the new boards either have a limited (sub 3.3V vdimm) after the mods, the mods dont exist, or the mods will work but only with a super heavy duty pot. Damn there ruining our fun! :'(
-CaT
maybe connecting straight to the dimm slot will work better? my voltages are stable, 3.36v, drops to 3.34v when running memtest, no fluctuations.
but how can u reduce it to 3.0 volt and will it destry my cpu?
You can use the direct 3.3v line method and get 3.0v with the correct resistor... I don't know the amperage on the vdimm circuit?Quote:
Originally posted by Demogorg
but how can u reduce it to 3.0 volt and will it destry my cpu?
I think it's about 7amps if I remember correctly... So, then if you want .3 or .4 voltage drop, you need a resistor that can handle that wattage
Can anyone test the amperage on the vdimm circuit to verify the this? at idle and full load?
Then we can get the correct resistor..:D (By my calculations you should be using at least a 16guage wire for the mod..
the resistor needs to be very small..
If my calculations are correct: Anyone remeber how to calculate this correclty..
I think it is: R = E / I , which would be .3v / 7a = about .042 ohms
or R * I = E, so .042ohms x 7amps = about .3volts
lol a 1/3ohm 25W resistor should do then eh? ROFL.
-CaT
the vdimm also goes to the cpu memory controller right? is thats whats causing some a64's to die? if so maybe we can find a work around for this by creating to circuits one using the 3.3 rail for just the memory and the other for the controller. as im sure just cutting the trace will not work cause im sure it has to be in a loop. whatcha think hell-fire? something similar has been mention but it looks like the idea quickly died.
Hell-Fire been awail sense you last post. Any progress.