D975XBX: CPU VID & BIOS problems

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08-31-2006, 04:59 AM
LeeCat

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D975XBX: CPU VID & BIOS problems

Brief description of my system:
- D975XBX rev. 305 with OC Debug mod.
- BIOS 1304/1334 (the same results and problem)
- CPU Pentium D940
- 2GB RAM
- Asus nVidia 6800.
I think the rest isn't critical but I can supply any additional info if required.

The problem:
Any setting for CPU VID in Advanced - Default Configuration Override menu does not change the value monitored in Hardware Monitoring window (see attachment). The same results I'm getting in Windows with SpeedFan. After getting the information that SpeedFan and similar 3d party software resets the CPU VID to default I cancelled the use of all 3d party tools at all and continue with original Intel tools such as IDU & IDCC only. It didn’t change the picture, still any settings in either BIOS or IDCC not reflected in both BIOS and IDU.

I can see the following possible reasons for it:
- Bugged voltage sensor;
- Bugged voltage regulator (does not react to VID change);
- Software bugs.

I don’t think the 1st one is valid – I can see the Vcore changes from 1.235V (CPU unloaded) to 1.212 - 1.213V (CPU fully loaded with ORTOS) in IDU which complies with “general logic”.

I don’t know what else I can do to prove either 2nd or 3d of possible faults, where can I do any physical measurements for Vcore on the board.

Any help will be much appreciated.
08-31-2006, 06:21 AM
Kango

LeeCat, this is a common problem with the D975XBX board. What I found necessary to get the new VID setting to "stick" is to 1) insure a reboot (the BIOS does not always enforce a reboot when you change VID) so you may have to exit Windows (or whatever OS) and reboot the system., or 2) Even #1 is a little flakey so as a precaution you should power off/on to get the new VID setting to work, or 3) Yes, even this will not stop some applications from resetting the SMBUS and thus resetting you VID to default. The alternative then is to set a new default by using the BIOS Configuration mode (change the BIOS jumper). Then boot into Configuration and set the new VID. Then power down, reposition the jumper and then reboot. That should always work.

I think this is a BIOS software bug. Intel had to tie together the setting of a new Vcore with the setting of a new VID in order to make sure EIST and C1E power modes work correctly. Other boards you just set a voltage value for Vcore. But for Intel, you set a new VID which is the same thing but different. On Intel boards, your are setting a voltage table offset instead of a voltage value.

HTH

PS - It may be necessary to disable EIST to get solutions #1 or #2 to work. #3 should always work, to the best of my knowledge. But #3 is the bigger hassle of the three. It's possible that none of this would be necessary if an EE part is used thus not requiring the OC DEBUG mod. Just a guess.
08-31-2006, 11:49 AM
LeeCat

Quote:

Originally Posted by Kango

LeeCat, this is a common problem with the D975XBX board. What I found necessary to get the new VID setting to "stick" is to 1) insure a reboot (the BIOS does not always enforce a reboot when you change VID) so you may have to exit Windows (or whatever OS) and reboot the system., or 2) Even #1 is a little flakey so as a precaution you should power off/on to get the new VID setting to work, or 3) Yes, even this will not stop some applications from resetting the SMBUS and thus resetting you VID to default. The alternative then is to set a new default by using the BIOS Configuration mode (change the BIOS jumper). Then boot into Configuration and set the new VID. Then power down, reposition the jumper and then reboot. That should always work.

I think this is a BIOS software bug. Intel had to tie together the setting of a new Vcore with the setting of a new VID in order to make sure EIST and C1E power modes work correctly. Other boards you just set a voltage value for Vcore. But for Intel, you set a new VID which is the same thing but different. On Intel boards, your are setting a voltage table offset instead of a voltage value.

HTH

PS - It may be necessary to disable EIST to get solutions #1 or #2 to work. #3 should always work, to the best of my knowledge. But #3 is the bigger hassle of the three. It's possible that none of this would be necessary if an EE part is used thus not requiring the OC DEBUG mod. Just a guess.

Thanks a lot for your answer, at least it makes me fill little bit better - I'm not so stupid not to be able to do the simplest setting. I tried tricks 1 and 2 already, I will try #3 on weekend. When you are talking about "BIOS Configuration mode" do you have in mind Maintenance mode?

Another question - what are thу reasonable/max settings for FSB/MCH voltages?
09-04-2006, 03:55 AM
LeeCat

Maintenance mode didn't help at all - any defaul CPU VID value does not change the measured one in BIOS and/or in Widows
09-04-2006, 04:32 AM
new-b

Most of the time #1 or 2 work for me.... but I have had the VID stuck to the point where removing the battery for about 5 to 10 minutes (with PSU power off) was the only thing that worked. May want to try that.
09-04-2006, 04:44 AM
LeeCat

Quote:

Originally Posted by new-b

Most of the time #1 or 2 work for me.... but I have had the VID stuck to the point where removing the battery for about 5 to 10 minutes (with PSU power off) was the only thing that worked. May want to try that.

Thanks, I'll try it. It's the :banana::banana::banana::banana:test board from Intel which I ever saw:( in my life