I don't think they would need much. Maybe just a voltage, vid pin tweak. A decade plus back, friend of family had a compaq desktop, socket 478 but willamette CPU, I think the stuff we could find on it at the time said it was willamette only. That might have just been the 400 bus, but anyway, we'd scraped up a 2.4 Northwood to try, stuck that in and it booted, but at 1.8Ghz because board didn't support 533. Left it like that because it was better than the 1.6 willamette anyway. Seemed to do fine a few years until bloat caught up with it. Maybe some situations might need the FID pins insulated or something in case the motherboard or CPU cares it's seeing the wrong thing.

Likely only a voltage mod, as AFAIK apart from the lower core voltage and the larger L2 cache there aren't any significant differences between Willamette and Northwood.
(at least not the first generation Northwood with 400FSB)

stamasd wrote on 2024-10-04, 18:36:

Likely only a voltage mod, as AFAIK apart from the lower core voltage and the larger L2 cache there aren't any significant differences between Willamette and Northwood.
(at least not the first generation Northwood with 400FSB)

Would it need a modded BIOS?

One like this ?

Yes it works, its even identified correctly by the BIOS and runs at 2.6.

Bought it a few years ago from eBay, I dont use it often as the system to attach a cooler to it needs to be replaced. IIRC ASUS also had a Motherboard and adaptor that worked in a similar manner, the adaptor wouldn't work with any other board but did allow up to 2.6 Northwood CPUs to run.

Trashbytes wrote on 2024-10-05, 01:42:

One like this ? […]
Show full quote

One like this ?

Yes it works, its even identified correctly by the BIOS and runs at 2.6.

The attachment QDI PlatiniX 4X.jpg is no longer available

The attachment 478 to 423 adaptor.jpg is no longer available

Bought it a few years ago from eBay, I dont use it often as the system to attach a cooler to it needs to be replaced. IIRC ASUS also had a Motherboard and adaptor that worked in a similar manner, the adaptor wouldn't work with any other board but did allow up to 2.6 Northwood CPUs to run.

Neato! Are ther any visible modifications on the adapter?

stamasd wrote on 2024-10-04, 18:36:

Likely only a voltage mod, as AFAIK apart from the lower core voltage and the larger L2 cache there aren't any significant differences between Willamette and Northwood.
(at least not the first generation Northwood with 400FSB)

I think it'd be a bit more involved than a simple VID pin mod. I have a D850MV board (i850 with S478) and my POST analyser displays -- when i plug in a Northwood CPU. Apparently Northwoods are supported on newer revisions of this board but not on mine.
It can also not work because it's an Intel board, they always lock their BIOSes down to a tee.

Boot_8046 wrote on 2024-10-05, 09:23:

Trashbytes wrote on 2024-10-05, 01:42:

One like this ? […]
Show full quote

One like this ?

Yes it works, its even identified correctly by the BIOS and runs at 2.6.

The attachment QDI PlatiniX 4X.jpg is no longer available

The attachment 478 to 423 adaptor.jpg is no longer available

Bought it a few years ago from eBay, I dont use it often as the system to attach a cooler to it needs to be replaced. IIRC ASUS also had a Motherboard and adaptor that worked in a similar manner, the adaptor wouldn't work with any other board but did allow up to 2.6 Northwood CPUs to run.

Neato! Are there any visible modifications on the adapter?

Ill try and dig the board out and take some pics, pretty sure the BIOS on this board has been modded to have Northwood microcodes, its an i850 board.

Trashbytes wrote on 2024-10-05, 09:44:

Ill try and dig the board out and take some pics, pretty sure the BIOS on this board has been modded to have Northwood microcodes, its an i850 board.

Speaking of which, would you mind sharing that modded BIOS? I have a PlatiniX 4x motherboard (currently with a Willamette 1.7 in it) and might want to give it a go some time. 😜
I also have a 478-to-423 adapter, which I've only ever used with a s478 Willamette, never thought of trying it with a Northwood.
(I don't know much about that adapter of mine, it came with a s423 PcChips motherboard I randomly picked on ebay a few years back)

stamasd wrote on 2024-10-05, 17:31:

Speaking of which, would you mind sharing that modded BIOS? I have a PlatiniX 4x motherboard (currently with a Willamette 1.7 in […]
Show full quote

Trashbytes wrote on 2024-10-05, 09:44:

Ill try and dig the board out and take some pics, pretty sure the BIOS on this board has been modded to have Northwood microcodes, its an i850 board.

Speaking of which, would you mind sharing that modded BIOS? I have a PlatiniX 4x motherboard (currently with a Willamette 1.7 in it) and might want to give it a go some time. 😜
I also have a 478-to-423 adapter, which I've only ever used with a s478 Willamette, never thought of trying it with a Northwood.
(I don't know much about that adapter of mine, it came with a s423 PcChips motherboard I randomly picked on ebay a few years back)

I might be able to do that for you, what's the exact model of the mobo?

Powerleap used to make S423 to 478 adapters, back in around 2007-2008 I used one on Gigabyte GA-8TX with a 2.6 GHz Northwood (400 MHz FSB) and it worked without any problems.

Boot_8046 wrote on 2024-10-08, 14:38:

stamasd wrote on 2024-10-05, 17:31:

Speaking of which, would you mind sharing that modded BIOS? I have a PlatiniX 4x motherboard (currently with a Willamette 1.7 in […]
Show full quote

Trashbytes wrote on 2024-10-05, 09:44:

Ill try and dig the board out and take some pics, pretty sure the BIOS on this board has been modded to have Northwood microcodes, its an i850 board.

Speaking of which, would you mind sharing that modded BIOS? I have a PlatiniX 4x motherboard (currently with a Willamette 1.7 in it) and might want to give it a go some time. 😜
I also have a 478-to-423 adapter, which I've only ever used with a s478 Willamette, never thought of trying it with a Northwood.
(I don't know much about that adapter of mine, it came with a s423 PcChips motherboard I randomly picked on ebay a few years back)

I might be able to do that for you, what's the exact model of the mobo?

It's precisely this one: https://theretroweb.com/motherboards/s/qdi-p6 … p4x-platinix-4x

stamasd wrote on 2024-10-08, 22:14:

Boot_8046 wrote on 2024-10-08, 14:38:

stamasd wrote on 2024-10-05, 17:31:

Speaking of which, would you mind sharing that modded BIOS? I have a PlatiniX 4x motherboard (currently with a Willamette 1.7 in it) and might want to give it a go some time. 😜
I also have a 478-to-423 adapter, which I've only ever used with a s478 Willamette, never thought of trying it with a Northwood.
(I don't know much about that adapter of mine, it came with a s423 PcChips motherboard I randomly picked on ebay a few years back)

I might be able to do that for you, what's the exact model of the mobo?

It's precisely this one: https://theretroweb.com/motherboards/s/qdi-p6 … p4x-platinix-4x

There's no bios image available on TRW, xan you dump yours please?