I'm currently using an E8600 on Win98 without any issues. Didn't need to disable one of the cores or anything.

From what I can tell, Win98 (and some programs like 3DMark) see that CPU as a Pentium 3, and everything works just fine.

Which processor do you already have?

E5800 is a 45nm, IIRC, which that board doesn't seem to support. Few LGA775/i865 boards do.

Joseph_Joestar wrote on 2023-12-09, 22:41:

I'm currently using an E8600 on Win98 without any issues. Didn't need to disable one of the cores or anything.

From what I can tell, Win98 (and some programs like 3DMark) see that CPU as a Pentium 3, and everything works just fine.

Interesting... I'm almost positive I read somewhere that the fastest core2duo recommended for 98SE was the e5800, but I could be mistaken.

I use a Core 2 Extreme x6800 on the same board with Windows 95 and the latest BIOS. Works great!

I agree with a previous comment; no need to disable cores with Win 9x. Windows 9x will ignore any extra cores.

tomcattech wrote on 2023-12-09, 22:46:

Interesting... I'm almost positive I read somewhere that the fastest core2duo recommended for 98SE was the e5800, but I could be mistaken.

I wouldn't worry about it too much. Plenty of people on this forum use an E8600 or something in that range for building a highly overpowered Win98 system. If you're interested in the full specs of my rig, I have them listed here.

It's total overkill for Win98, but that was the goal. That machine can play any game released before 2002 at 1600x1200 with AA and AF cranked up, while maintaining 60+ FPS.

The P5PE-VM can handle 45nm CPUs with the modified BIOS... The E5800 is the best choice, because it has a native 800Mhz FSB. Running the 865 northbridge at 1066Mhz FSB is not a good idea, but it is possible. It will get very hot at that speed.

mockingbird wrote on 2023-12-09, 23:46:

The P5PE-VM can handle 45nm CPUs with the modified BIOS... The E5800 is the best choice, because it has a native 800Mhz FSB. Running the 865 northbridge at 1066Mhz FSB is not a good idea, but it is possible. It will get very hot at that speed.

Where can I get the BIOS in question?

tomcattech wrote on 2023-12-09, 23:58:

Where can I get the BIOS in question?

Here you go.

mockingbird wrote on 2023-12-10, 00:50:

tomcattech wrote on 2023-12-09, 23:58:

Where can I get the BIOS in question?

Here you go.

p5pe-vm.zip

This worked amazingly.... Thanks!

tomcattech wrote on 2023-12-09, 21:39:

The Plan is to use a core 2 duo processor as a base after disabling one of the cores.

Just FYI : You can't, at least not on at least 90% of boards out there (there is no option for it in BIOS).
The only way to disable one core is to do it from Windows (via "msconfig" menu).

Windows 98 doesn't need that though, since it only sees/uses one core (second core simply "hangs around").

mockingbird wrote on 2023-12-09, 23:46:

The P5PE-VM can handle 45nm CPUs with the modified BIOS... The E5800 is the best choice, because it has a native 800Mhz FSB. Running the 865 northbridge at 1066Mhz FSB is not a good idea, but it is possible. It will get very hot at that speed.

Is there a list somewhere of motherboards with modified BIOSes for 45nm CPUs? I feel like I had reviewed the big list that's somewhere around here a few months ago and maybe I missed that...

(it seems like all the boards with official support are pretty much unobtainium at this point e.g. the Asrocks)

Here's some source for Xeon moded ones (including 45nm) : https://genius239239.neocities.org/771/771

VivienM wrote on 2023-12-10, 15:48:

Is there a list somewhere of motherboards with modified BIOSes for 45nm CPUs? I feel like I had reviewed the big list that's somewhere around here a few months ago and maybe I missed that...

(it seems like all the boards with official support are pretty much unobtainium at this point e.g. the Asrocks)

There are two kinds of modifications (and someone will correct me if I'm mistaken, I hope)... The first, as with the P5PE-VM for example, has something modified at the low level to accept 45nm CPUs. The second is just a BIOS with microcode added or replaced. This kind of motherboard would have booted with a 45nm CPU, but the extra functions (SSE4.1 and such) wouldn't be recognized.

Check out this database:

https://ideafix.name/?page_id=4351

mockingbird wrote on 2023-12-10, 00:50:

tomcattech wrote on 2023-12-09, 23:58:

Where can I get the BIOS in question?

Here you go.

p5pe-vm.zip

Hello. New member here. I'm a fan of retro PC building that's why when I need information, I always check this site to find information.

I have a P5PE-VM with a Celeron 420, 512mb of ram, ATI Radeon X800 Pro AGP and I'm using this as my Windows 98 PC.

I'm curious about this modified bios that's why I downloaded it.

There are 2 folders there: 1501 and 1501_LLC.

Question is which is to choose? I just want to use the best bios because as we all know, bios flashing is risky.

I have an E5800 lying on my storage and want to try to install the CPU on my P5PE-VM.

Thanks!

majorpayne19 wrote on 2024-03-28, 03:58:

There are 2 folders there: 1501 and 1501_LLC. […]
Show full quote

There are 2 folders there: 1501 and 1501_LLC.

Question is which is to choose? I just want to use the best bios because as we all know, bios flashing is risky.

I have an E5800 lying on my storage and want to try to install the CPU on my P5PE-VM.

Thanks!

Good question - I don't know... Anyone else care to chime in?