posted
Here's a pictorial of the Standard Vdimm Mod. That is connecting the +3.3V bus to the Vdimm line.
If you do this mod, your doing it at your own risk. The Rebels Haven Computer Forum will not be responsible for damaged systems or components... If your unsure about the mods, I strongly suggest you do not implement them...
These are the 3 pins that bring the +3.3V to the board:
These are the 3 pins on the back of the board. Looking carefully, one can see the track connecting them:
This is the plus(+) terminal of one of the capacitors thay filters the Vdimm voltage:
This is what the completed mod looks like before soldering the wire in place. #22 or #24 gauge wire is fine for this application:
-------------------- Too Many Computers,... Too Little Time ..... Damn Phenoms! Posts: 25194 | From: Fire Island, NY | Registered: Feb 2003
posted
Here's another way to do the Mod. The picture shows the points to connect with mini-grabber clips. This also connects the 3.3V bus to the Vdimm rail and the memory sees 3.3V...
(Pic borrowed from xtremesystems until I get a close up)
-------------------- Too Many Computers,... Too Little Time ..... Damn Phenoms! Posts: 25194 | From: Fire Island, NY | Registered: Feb 2003
posted
So Polygon, you say to complete the mod you put grabbers between those two points on the mosfet?
Is there any way create adjustable VDIMM using a pot?
I imagine with this setup, you get 3.3 volts, or by disconnecting the grabbers, you get back to the stock setup?
3.3 or nothing is OK, as long as I can revert back to stock (some TCCD don't like volts). I would prefer adjustability though.
Posts: 234 | From: Japan | Registered: Dec 2004
posted
This kind of soldering on those big pins I think I can do. I will try this on my second MSI board which has the 0452 Korea chipset. I think this one likes BH-5.
However my 3.3 rail is maybe low and I don't want to mess with the PSU. I think I can get 3.28, enough for 250 on my Corsair.
The Booster is no go. If you run in the last slot, it touches the heatspreader of the second stick of ram, heating it up to 51 C! If you run in the 2nd slot, it don't work right. Can't run in the 1st slot as have a cap in the way. Besides, ram works best in the #1/2 slots on this board.
In either case, the thing puts out tremendous radiant heat! I am looking for asbestos gasket so I can cut a sheet to isolate the ram, except it's been banned so hard to find these days.
Posts: 234 | From: Japan | Registered: Dec 2004
I have done this mod on several boards that have a "Linear Regulator" for the Vdimm power supply... That is the MSI Neo2, the Gigabyte K8NF-9, The Shuttle AN35/N, and the MSI Neo4...
On boards with "Switching Regulator" Vdimm power supplies, I modify the voltage control loop to increase the voltage... Those are the Jetway N2PAP-Ultra and the Epox-9NDA3+.....
A motherboards manufacturer's forum, will never OK board mods... They don't want to be responsible....
The only problem I ever have with this mod was some memory doesn't like 3.3V...
Anyhow, that's it in a nutshell.. If I were you, I'd get some memory that is compatiable with nF3/nF4 boards... High Performance Memory and the Neo4 topic tabulates the results of testing of several brands on this board...
Anyway, welcome to the forum....
-------------------- Too Many Computers,... Too Little Time ..... Damn Phenoms! Posts: 25194 | From: Fire Island, NY | Registered: Feb 2003
posted
Without a schematic of the motherboard, we don't know if something is being overstressed or not. All we know is that this is a "common" mod that is described in many overclocking forums, and I don't know of any failures due to the mod...
Regarding the memory, I bought 5 of the most popular S939 Motherboards, so that I could document their quirks and determine what it takes to get them going, and get them overclocking to respectable levels...
It didn't take long before I realized how fussy the new boards are with brand/model of memory... So I bought around 5 different brands of high performance memory... I tested all the memory on all the different boards to determine which memory brand and model each board likes... The results of those tests are here and here....
The toughest idea for new A64 board owners to accept is that the memory they have used at great settings on 32 bit boards, doesn't work worth a damn on their new board... Forget "Value RAM" if you expect to clock to 300FSB... Forget memory with Hynix Chips that are typically used in PC4000 to PC4500... The new boards will not clock to 300FSB with Hynix Chip memory... Forget Mushkin memory with BH-5 chips unless your prepared to run 3.6Vdimm!.... The nF3/nF4 boards only like "TCCD" memory, but not every brand... I must emphasise that all brands of "TCCD" memory are not equal and that all brands of "TCCD" memory will not overclock well..
Another quirk of these boards that is tough to accept, is that what works for one board user, may not work for another board user, with the exact same components... Right now I only know of two brands/models of memory that that happens with... But they are both with the same board...!
-------------------- Too Many Computers,... Too Little Time ..... Damn Phenoms! Posts: 25194 | From: Fire Island, NY | Registered: Feb 2003
posted
ok done the one wire mod and ma A64 3200 winchester is flyin along @ 2.5ghz / 250 HTT x 4 / 1.475v / Rams 1:1 (250x2) / 2-5-2-2.0 1T @ 3.3v .. thanx for the info rebel or i never would found this out..
benches in Everest are now,
7176 Mb/s Read 2209 Mb/s Write 37.0 ns Latency
and im glad i left the XP-M behind...
-------------------- Neo 2 Platinum A64 3200 90nm @ 2.5 Ghz @ 1.475v 2 x 256mb HyperX PC3200 BH-5 @ PC4000 @ 5-2-2-1.5 3.3v 2 x 120Gb SATA Raid 0 Radeon 9800 Pro AIW NEC ND2500A DL DVDRW Tagan 480 Watt PSU Posts: 5 | From: London, England | Registered: Feb 2005
posted
Yeah newer HyperX maybe be TCCD but these are week 33 of 2003.
not to sure if BH-5`s were still being produced then but kingston had bin loads im sure.
These love the voltz so i can only assume BH-5 as ive never had the spreaders off.. the guy i got em off assured me they were BH-5 and they seem to perform like em 5-2-2-2-1.5 id say BH-5
They scale so good i wanna throw em 3.4 - 3.6 with some serious cooling on em..
-------------------- Neo 2 Platinum A64 3200 90nm @ 2.5 Ghz @ 1.475v 2 x 256mb HyperX PC3200 BH-5 @ PC4000 @ 5-2-2-1.5 3.3v 2 x 120Gb SATA Raid 0 Radeon 9800 Pro AIW NEC ND2500A DL DVDRW Tagan 480 Watt PSU Posts: 5 | From: London, England | Registered: Feb 2005
Damn Phenoms!
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