I cannot say, how it will be in this case, but I myself operate Pressler D935 on Gigabyte 8I865GME-775-RH rev.1.x, which is not listed in supported CPU and everything works without problems. In the line to the Russian forum, the user describes the full functionality of Cedar Mill on the P5GD1 board, although it is also not listed as supported. The only problems are CPU identification when loading the microcode and then in the Asus AiBooster is jumping the CPU multiplier and frequency, in Everest everything is fine, also in the Asus PCProbe. Test in Prime95 9 hours OK.

Well, I ordered it. Let's see what happens.
Will come back and update.

(Not gonna lie, paying for a P4 in 2021 feels weird)

Cedar Mill should be compatible with almost anything.

andrea wrote on 2021-04-26, 19:00:

(Not gonna lie, paying for a P4 in 2021 feels weird)

Really, it looks a little perverse 😀
But seriously - I also think it will work without a problem, and Cedar Mill (and Pressler), thanks to 65nm technology, at least raised a bit of the flag Pentium 4. There was nothing they could do about NetBurst's architecture, and they had no chance against Intel Core, but at least they had corrected the poor reputation of Prescott's "heaters." I was an AMD fan in the days of LGA775, so I only got Pressler of interest for 4 euros to a board that was free of charge.

I've heard it depends on the VRM design, because Cedar Mill has different power requirements compared to Prescott-2M. If you get it to work make sure it's not getting wildly overvolted.

andrea wrote on 2021-04-26, 19:00:

Will come back and update.

Please share an update on your results.
There are D0 stepping Cedar Mills usually having VRM config 06 as well as older B1 and C1 ones usually featuring 05A VRM config. Those are more likely to run as this is similar to Prescotts

Beware, there are two types of Cedar Mill. One with 86W TDP and another with 65W TDP. I encountered behaviour, that motherboard took only 86W TDP one, but not 65W TDP. So I would extend original table even to this:

To the best of my knowledge between 2004 and 2006 there were 3 versions of the 775 socket:
1. Prescott only
2a. Prescott, Cedar Mill (86W TDP)
2b. Prescott, Cedar Mill (86W and 65W TDP)

Btw, I'm also waiting for confirmation, if Asus P5GD1 supports Cedar Mill, with only CPU error code, but motherboard works fine.

Here's my result with P4 651 (SL9KE) and P5GD1 on Win10 x64 after patching the bios with F65 micro code:
also avoid P4 661 (SL96H), it has the same vrm spec as Pentium D and will not post on any single core motherboard.

Thank you for great news. What PCB revision is your P5GD1? BIOS version is latest? Did you try it without updating the microcode?
Are you planning to upload picture of your board to TheRetroWeb? Maybe, that modified BIOS would come handy for others. (including me 😀)

I'm checking, P5GD1 is still not on Theretroweb... only pro version.
https://theretroweb.com/motherboards/?showIma … es=1&name=p5gd1

Bruno128 wrote on 2023-05-18, 20:46:

andrea wrote on 2021-04-26, 19:00:

Will come back and update.

Please share an update on your results.
There are D0 stepping Cedar Mills usually having VRM config 06 as well as older B1 and C1 ones usually featuring 05A VRM config. Those are more likely to run as this is similar to Prescotts

Sorry, I didn't see your post until today.
My reply probably isn't what you want to hear though, the eBay 5€ Cedar Mill from China got lost in the mail, and the HP prebuilt went in the bin. 😒

W.x. wrote on 2023-07-21, 20:18:

Thank you for great news. What PCB revision is your P5GD1? BIOS version is latest? Did you try it without updating the microcode?
Are you planning to upload picture of your board to TheRetroWeb? Maybe, that modified BIOS would come handy for others. (including me 😀)

It's rev 1.05 and looks like this: https://www.newegg.com/p/N82E16813131503
without the microcode it always halts on missing ucode message and you have to hit F1 to boot and I don't think you can install x64 version of windows without cpu fully recognized.
patched v1014 bios :

wow, thank you. I have 1.05 too. That's awesome. Have also Gigabyte GA-8i915p pro, but that don't support Cedar Mill eighter. This is so awesome news for me, because I was so disappointed, that all three boards of mine with 915P (or G) don't support Cedar Mills. Now I see at least 1 does (with moded BIOS).

I suppose you could try strapping the vid pins until CPU asks for a voltage the board supports. Obviously you don't wanna have to go too mad, but 0.1v either way can be tolerated, and it's usually the fractions of that that trip things up.

Karbist wrote on 2023-07-21, 21:09:

patched v1014 bios : P5GD114.rar

Thank you for uploading the modded BIOS.
Added: P5GD1

I have an HP Pavilion zd8000 from 2004 that only takes Prescott and Prescott-2M chips... unfortunately when putting my P4-661 in the machine will not boot up; it powers on and the fans spin up but that only lasts for a second until it shuts off. I have heard the 661 uses the same VRM config as the Presler chips so this might not work unfortunately. However I'm sure its possible but I will need a microcode update. The board these use is known as the Quanta NT2 (I have uploaded a copy of the schematics to Archive.org) and it runs a Phoenix BIOS. The system has a 915P chipset. I would love to get cedar mill chips to run on here but it seems as though I can't find out how to mod the chips to work on older 915 boards in the first place. It would be a wonderful upgrade from the Prescott and P-2M chips in a sense that it would be more efficient, especially with a DTR laptop like the zd8000.

Karbist wrote on 2023-07-21, 17:53:

Here's my result with P4 651 (SL9KE) and P5GD1 on Win10 x64 after patching the bios with F65 micro code:
also avoid P4 661 (SL96H), it has the same vrm spec as Pentium D and will not post on any single core motherboard.

651.jpg

That's odd - my P4 661 and 670 work fine on both my Foxconn 865G7MF and my Abit AS8... the 670 does get unusually hot on the Foxconn board tough... And they both work fine with Pentium D chips... maybe they're not "single core only" boards? If not, then what would be a single core only board?

k24a1 wrote on 2023-08-26, 15:45:

However I'm sure its possible but I will need a microcode update.

It's cool that the laptop has a desktop socket but adding microcodes most likely won't work. The VRM designed in 2004 is not fit for Presler or Cedar Mill (VR config 06)

Socket3 wrote on 2023-08-27, 21:12:

maybe they're not "single core only" boards? If not, then what would be a single core only board?

There is even a 865-based board that supports Core2Quad processors.
Unlike 865 which offers interesting options, 915/925/X/XE is mostly a dead-end.

Bruno128 wrote on 2023-08-27, 23:35:

Socket3 wrote on 2023-08-27, 21:12:

maybe they're not "single core only" boards? If not, then what would be a single core only board?

There is even a 865-based board that supports Core2Quad processors.
Unlike 865 which offers interesting options, 915/925/X/XE is mostly a dead-end.

Interesting. I've yet to come across one such i915/925 board myself tough. I have a few boards with these chipsets - haven't played much with them, but all of them seem to work fine with any pentium 4 and pentium D chips I've tried. Some even work with newer Pentium Dual Core CPUs. I haven't actively looked for any board with these chipsets, but I've them in loads of computers picked up from schools, public institutions and even while dumpster diving for electronics. Mostly Asus, Gigabyte and MSI, although I also have a couple of interesting Biostar boards - one in particular has DDR2, PCI-E, i915 chipset but is socket 478 (but that's off topic).

A couple of months ago I was playing around with one such PC - trying to build a dirt cheap winXP retro PC for a friend - it came with some gigabyte motherboard, 1GB of DDR2, no video card and - surprisingly - a Pentium Dual Core e2160! Most of these PC's come with a Celeron or Celeron D, but this one was different.

I also remember messing about with an Asus - can't remember what model, but it had an intel 915 chipset - P5GD or P5GD2 perhaps? - the system I liberated it from came with a Celeron D, and despite no mention of compatibility on Asus's website, the board booted up and ran fine with a Pentium D 925....

On the other hand, I've had little to no luck upgrading OEM systems that use the chipsets you mentioned. I tried swapping dual core chips into Dell Optiplex, IBM Netvista and HP i915 or i925 prebuits with no success..... maybe this is mostly an OEM thing?