Universal LGA775 VID mod question.

[Retrorockit]

I've been studying the VRD11 Voltage tables for the Core 2 Duo family of CPUs on LGA775. I found a number of settings that involve all VID pins=0 but one.
This could be done playing around with tinfoil to pull them all low, and then tape the desired pin HI to get the desired Voltage range. I call it a range because I intend to adjust it lower as needed with Throttlestop under clocking software.
the advantage of pulling all VID LO would be that you don't need to know the original Voltage of the CPU. Just do the mod and run it.
It has occurred to me that since they will all be the same (the pull down part) maybe a solder mask would be the way to do this instead of playing around with tinfoil and glue.
I'm a retired truck mechanic and have almost no hands on electronic experience. So let me know what you think, and some idea how to go about this, materials techniques whatever.
The unlocked Voltage would allow BSEL tape mods on any CPU, and on locked BIOS motherboards.

[Retrorockit]

Re: Universal LGA775 VID mod question.

I think I've found a way to do this. Garden supply shops sell adhesive backed copper tape to keep snails out of flower pots. That may be the thing I need for this.

[Retrorockit]

Re: Universal LGA775 VID mod question.

This image was shared on some other forums. I thought you "guys" might like it too
It's a lot easier than working from the socket diagram which must then be reversed for the CPU mods..
https://www.overclock.net/cdn-cgi/im...6-png.2541989/

BTW I know some of you still use P4 stuff here. Those use VRD10 which works completely differently than VRD11 which is the Core2 family of CPUs.
This includes 2CPU LGA771 Xeons which just have the notches in a a different place.

[momaka]

Re: Universal LGA775 VID mod question.

Thanks for sharing this!
I find it quite cool how all of the VID pins are so conveniently located next to a ground pin, as if asking to be pulled low by this mod.
Copper tape or aluminum tape may indeed work well here. Though I still haven't tried OC'ing any of my C2D stuff yet - not through BSEL modding or Throttlestop anyways.

BTW I know some of you still use P4 stuff here. Those use VRD10 which works completely differently than VRD11 which is the Core2 family of CPUs.

That's probably only me, really. (At least for daily stuff anyways.)
And yeah, I haven't ever dreamed of trying to over-volt my Pentium 4 Press-hot CPUs - they already run hot enough as it is.
(On a fun note: this may be worthwhile doing for the winter months when I want my computer room to feel "toastier" / cozier. )

[Retrorockit]

Re: Universal LGA775 VID mod question.

When I own a Dell I always want to find a way to get a respectable overclock. The Optiplexes with their 95W CPU limit have thwarted me so far. Best effort has been an X5470 Xeon swap in an Optiplex 380. I guess they forgot to apply the 95W limit to that bottom feeder model.
Pulling all the relevant pins LO sends the Voltage over the High limit. All taping of pins to HI
reduces the Voltage by varying amounts. It's a descending binary matrix. Each VID pin has a certain V. reduction value. VID7 just selects the VRD11 table. VID6 needs to be LO for any value over 1.2000V. VID 0 decreases by -.00625V and can be disregarded also.
Starting at 1.6125V. (which won't run).
VID1= -.0125V.
VID2= -.0250V.
Vid3=. -.0500V.
VID4= -.1000V.
VID5= -.2000V.
I have some Copper EMI tape with conductive adhesive on the way. The Pentium E5xxx CPU series looks interesting with multipliers from 13-16x
If you want a space heater just Throttlestop a QX6800 to 4GHz!
https://valid.x86.fr/bg4n0r

[stj]

Re: Universal LGA775 VID mod question.

there is a good chance this wont work,
the bios will identify the cpu revision and model and then check it's microcode tables for a match.
no match - no bootup.

so if you want to do something unusual you first need to mess with the bios.
in which case you can often unlock the voltage settings from there anyway.

one other thing, a lot of boards just dont have the parts to supply over 90w to the cpu, you will either kill the circuit or it wont be stable.

[Retrorockit]

Re: Universal LGA775 VID mod question.

The microcode will be the same. Gigabyte does use a lookup table that defeats pinmods. But Dells have been overclocked this way for years. It's just that the extra Voltage wasn't there for the more interesting combinations.
Q6600 G0 from 2.4Ghz to 3.0GHz is a classic, and the E7500 from 2.93 to 3.67GHz is another.
The E7600 to 3.83GHz needs some extra Voltage.
Unlocking a Dell BIOS is easier said than done. Aside form adding some CPU support it hasn't happened yet.

[Retrorockit]

Re: Universal LGA775 VID mod question.

As far as power for the CPU goes some of the Dell boards are surprisingly good.
The T3400 workstation/ XPS 420 can run the 130W QX9650 beyond 4Ghz. How far???? 400fsb also.
My Optiplex 380 which was sold with 65W 2 cores and 4GB RAM ran a 120W Xeon X5470 with no problems. 8GB DDR3 too. But most of the Optiplexes have an artificial 95W CPU limit that the chipset does enforce at startup. But an overclocked 65W 2 core can fit within that envelope anyway. Dell doesn't put any cooling on the VRM. It can be added to extend the
capacity. The Optiplex XE (Extreme Environment) has a 4 phase VRM that's designed for high temperature 24/7 running.I haven't tested one yet. The DT sized case will make the CPU cooling a challenge.

[Retrorockit]

Re: Universal LGA775 VID mod question.

If you want to keep your feet warm just light the fuse on this baby!

https://www.techpowerup.com/forums/a...003-jpg.99714/

[Retrorockit]

Re: Universal LGA775 VID mod question.

First try out it didn't work so well. No smoke this time. But no computer either.
I'll have to get a 2nd rig going. My daily computer is a good candidate for this once I get the bugs out. But not for trial and error. I guess I'll have to try the VID mod the old fashioned way and see what I discover. It looks like one of the MIL Spec. Optiplex XEs is going to get a workout. maybe I need to go straight to spoofing the MB VRM and be done with it.
I suppose Linux is as good as anything else for these hardmods.At least I got to clean all the cat hair out of it.

[momaka]

Re: Universal LGA775 VID mod question.

If you want to keep your feet warm just light the fuse on this baby!

https://www.techpowerup.com/forums/a...003-jpg.99714/

Hehe, with a Radeon HD6990 in there, it won't be just your feet that getting warm.

Really nice build, BTW!