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What would the VPIN mod do to a Prescott?

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BrianH2O

Member
Joined
Aug 19, 2002
The VPIN Mod allows for up to 1.85v from a NW processor from a default of 1.5

Would I get 1.75 from the same mod on a 1.4v prescott??
 

batboy

Senior Moment
Joined
Jan 12, 2001
Location
Kansas, USA
First off, 1.75v will probably fry a Prescott system. If you go to the link I provided and look at table 3 (voltage identification definition) it only lists vcores up to 1.6v. It almost looks like Intel designed it to be confusing. In all cases that I could see, you would have to do a combination VID pin wire wrap and then also isolate a pin at the same time.

http://intel.com/design/Pentium4/datashts/30056102.pdf
 
OP
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BrianH2O

Member
Joined
Aug 19, 2002
Here is me thinking out loud ....

I set the VCore to 1.6 in the BIOS. But I get actually 1.505 to 1.568 under load. The bios will not go higher than 1.6. If I could get 1.65 in the BIOS, then maybe I can get a real 1.555 to 1.618 under load.

I can run at 3.9ghz stable. At 4ghz, the machine randomly locks up ... probably when it hit the lower VCore range. I believe a lock up is due to insuffiecient voltage for Intel CPU's.

My prommie at 3.9 hits a max of -26c evap, -7c CPU loaded. I think I can handle the bump in VCore????
 

batboy

Senior Moment
Joined
Jan 12, 2001
Location
Kansas, USA
With a prommie, you can "probably" handle a little more vcore. I would say that even with phase change cooling, that 1.6v real measured load vcore is getting close to the limit. If you really want to try this, I will help. But first you need to be positive about what default vcore you have because that is critical in determining what to do next.

With a default 1.4v, that means VID1, VID4, and VID5 are all connected (high voltage level) and VID0, VID2 and VID3 are not connected (low voltage level). Since VID4 is on the outside row, it would be easier to isolate than the other VID pins.

If you truly have 1.4v default, then about the easiest thing to do is a modified 1.5v. This requires you to wire two pins (VID2 and VID3) and isolate one (VID4). A modified 1.475v is the next easiest and might be a safer voltage. In addition to everything needed with the modified 1.5v, you also need to connect VID0 too.

Do a search on isolating pins. This can be done several ways. I've heard of people putting several coats of clear fingernail polish on them (with only limited success). I've heard of people using like a 22 gauge wire insulation and slipping over the pin. I've also heard about people just breaking off the pin (I don't recommend this method).

Before you remove the CPU, go into the BIOS and manually set the vcore to something like 1.4v and then save that setting. That way, if we are wrong about the default vcore or the pins, you won't fry your CPU. Make sure you absolutely know what your default vcore is first. Good luck.
 
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BrianH2O

Member
Joined
Aug 19, 2002
My first boot was default setting and yes the default was 1.4v. I will probably have time to try this this weekend. I plan on using the 22 gauge wire. Have do it before. My first boot will be stock everything to get a reading on the VCore.

I will research how to isolate the pins.

Thanks
 

batboy

Senior Moment
Joined
Jan 12, 2001
Location
Kansas, USA
batboy said:
This requires you to wire two pins (VID2 and VID3) and isolate one (VID4).

When I say you need to wire two pins, I mean you need to connect those two pins to another pin that is already internally connected. In this example, wiring VID2 and VID3 to VID1 would be the easiest, so you are actually wiring three pins together. When I reread my post, I decided what I said might be confusing. If you only wire VID2 and VID3 together and nothing else, that won't do anything since neither pin is internally connected. Hope that makes it a little more clear.
 

batboy

Senior Moment
Joined
Jan 12, 2001
Location
Kansas, USA
In the pic below, VID4 and VID3 are connected. VID4 is the outer most pin that is wired. For a modified 1.5v (if my logic is correct), you need to isolate VID4 and wire the next three pins together (to the right of VID4). Make sense? I would crisscross the wires in between pins to make more contact and to allow the wire to stay on better.

image005.jpg