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DFI LanParty UT nF3 250Gb 5V VDimm Mod

Discussion in 'Articles' started by celemine1Gig, Aug 17, 2005.

  1. celemine1Gig New Member

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    Last edited by a moderator: Oct 2, 2005
  2. DanTheBanjoman SeƱor Moderator

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    Looks nice, I don't like soldering on my hardware though (nor do I have this board)

    On the PC-DL user forums they did a similar thing without soldering. Perhaps interesting for some users.
  3. celemine1Gig New Member

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    I agree that the solderless methods might be neat for some mods like simple VDimm Mods or something like that, but for the 5V as Vdimm-Source Mod this is absolutely not adviseable. In case of this mod you need a permanent and low resistance connection between the cable and the MOSFET source-pin. A grabber's connection-resitance increases over time and that could lead to serious problems here. Furthermore as explained in the guide above, there will be quite some amps flowing through that cable and I doubt that a non permanent connection like a grabber could take that.
    So it's a nice idea, but not a proper way to do this mod.
    I always solder my mods because I don't like the fact of the increased resistance after some time of use. And if you got some practice and you work carefully, soldering isn't that hard. Just don't rush it.
  4. Golden Flamer New Member

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    Great mod celemine! :)

    I see that my max VDIMM Voltage oin this board is Vsource - 0,2V. My 3,3V is 3,35V, so my max VDimm is about 3,16V without any mod. With this voltage my Best BH-5 RAM (768 Mb Total, 1x512Mb Corsair PC3500 stick, + 1x256Mb Mushkin Lvl2 PC3200 Bh-5 Stick) can do about 251MHz at most aggressive timings.
    I don't have time to analize the circuit, but I think ABOUT A LINK BETWEEN PSU 3,3V RAIL and VDIMM MEAUSER POINT ONE THE MOSFET PIN. WHAT DO YOU THINK ABOUT THIS, IS THIS POSSIBLE?
    If This mod work I think RAM become always filled with full 3,3V RAIL, This should cut off all the RAM's Voltage Supply Circuit. VDimm become fixed at the 3,3V rail value.
    Is this dangerous?
  5. celemine1Gig New Member

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    Don't do this!!! It could possibly destroy some of your hardware. If you really want to mod the board in order to always feed VDimm with the 3.3v-rail directly, then do it right. I had the following mod running for a day while working on the 5V-mod described above. The 5V-mod wasn't done yet and I had to get the board up and running for a quick test so I did the vdimm=vio mod (i.e. vdimm = PSU's 3.3V-rail).
    But if you do this you should also remove "Q50"'s source-pin from the PCB (in order to keep the mosfets alive). Then you check the capacitors next to the VDimm slot with a multimeter set to continuity test for connections to "Q38"'s source-pin (this pin is one of the VDimm measuring points, too). If you have found the two capacitor contacts, solder wires to these capacitor legs and not directly to any pin carrying vdimm! Doing it my way will give you clean, filtered voltage instead of having unfiltered, perhaps a bit fluctuating volltage directly from the PSU.
    But I didn't describe that mod before because I don't like it very much and I don't think that it's optimal. You can't set vdimm to anything lower or higher than your 3.3V rail, thus you are still very limited.

    That's exactly why I came up with my 5V-Mod. ;)
    Last edited: Sep 1, 2005
  6. Golden Flamer New Member

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    Thank you Celemine, I understand.
    Previous I want to do this 3,3V direct voltage mod because I don't want to let my PSU's 3,3V rail USELESS and don't want to stress to much my 5V rail, beacuse my 5V rail is already very stressed by my hungry Video Card, an ATi Radeon 9800 PRO All-in-Wonder. Unfortunately this Video card, expecially when is extreme overvolted and overclocked at 472/796 like mine, eat a lot of watts from 5V rail :|
    But my PSU is not a weak PSU: It's a Thermaltake buttefly purepower 480W.

    Do you know how much Watts or ampere a memory like my BH-5 should eat? (approximately).
    I use 768Mb of total BH-5 based RAM, 1x 512mb of corsair PC3500 and 1x 256Mb of Mushkin Level2.
  7. Unregistered Guest

    Normally the RAM shouldn't draw more than 10-15W. I'd guess (I don't know that for sure) highly overvolted and overclocked RAM should reach a max. of 30W. That means that while drawing it's power from the 3.3V line, it should need something between 3-5Ampere. But on the 5V line the amperage would be lower as the wattage stays the same, but the voltage is higher. So it should be about 2-3Ampere. You see those numbers are far from totally stressing a good PSU.
    And well, if you say your PSU is already at its limit, then it can't be good, it's as simple as that. And BTW, don't believe any software reading until you have veryfied it with a Digital Multimeter. ;) Go ahead and measure the voltages on your own under load with a DMM. Then you will see if your PSU is already really stressed, or if only the Software readings make it appear that way, or even the mobo is the component that is stressed, perhaps a bit too much.

    I have a Topower PSU, for example, with a 5V line that is rated for 50A. That's 250W of theoretical pure power just for the 5V line. I don't think that max. 30W would do much here, even if your 5V line is rated a little lower. ;)
  8. celemine1Gig New Member

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    That was my answer BTW. Just forgot to log-in. :)
  9. celemine1Gig New Member

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    Little update in the first posting. Tried something today on the hardware vdimm-mod and inserted it into the original text. ;)

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