Hi,

I have been thinking about putting a later 533FSB Pentium M Dothan CPU with PAE/NX support in my T42.

Although, I cannot enable PAE through the BIOS on the ThinkPad T42, will PAE/NX still be "supported" so as to enable installing Ubuntu 12.04 and Windows 8?

I was hoping that some of you tweakers out there with T43 CPUs in the older T42 could could share some light on this?

All the Best,

Physically it will fit, but that is about all.
It will probably work as well (for a few seconds or minutes, or even longer if you are lucky).
But it will only run at 400 FSB, thus lowering the end clock speed by ~25%.
I wouldn't run the risk of using the wrong CPU. Some blow job will happen!
This is bound to end up in tears!

Unless you're up for overclocking via pinmod, there's absolutely no reason for a 533Mhz CPU in a T42...

Excuse me for being real annoyed as i tried to install latest Ubuntu on my T41p, who came up with the bright(stupid) idea to have PAE enabled in 12.04 Ubuntu?

Most 32-bits systems won't benefit from PAE anyway in performance as the memory slots often can't handle larger than 1GB modules anyway. specially with old laptops like T4x with only 2 slots...

The reason for Linux being old hardware friendly is against the established linux community rules, i just think the PAE enabled thing is really stupid.

How about the two 2.1GHz B0 Stepping 400FSB Pentium M 765 CPUs SL7UZ and SL7V3?

Are there any T42 series owners out there with one of these CPUs that can vouch for their PAE/NX ability?

SL7V3 was the stock CPU on top-shelf T42/p units such as 2373-Q1U/Q2U and their derivatives. So yes, that one works on any 400Mhz T4x machine.

The other one (SL7UZ) is not socketed but meant to be soldered to the board so it's a no-go.

No clue on PAE/NX abilities, sorry to say...but am willing to bet that if the other applicable CPUs don't possess them (SL7EN, SL7EM itd.) SL7V3 will behave in the exact same way...

Some years ago I've tried to run 533MHz FSB Dothan CPU in Dell Latitude D600 (designed for CPUs with FSB 400MHz). It worked, but the performance was much lower than expected, at least provided the same performance as Banias CPU.

This is baloney, running the CPU core at 25% lower clock speed will NEVER cause a problem, except if the CPU somehow uses dynamic memory logic for some of its high-usage registers (e.g. for the program counter) but even then, I imagine you'd have to run the CPU at least 10x slower to create a loss of memory from the DRAM registers in the CPU.

The big question is, if you install a high-speed Dothan CPU (760, 770, or 780), how much can you increase the FSB (from 100 Mhz up to maybe 133 Mhz ??) to get back some of that loss in clock speed in the CPU core? For example, if you can clock your bus at 467 Mhz, then a 2.26 Ghz Dothan 780 would behave like a 2.26 * 467/533 =~ 2.00 Ghz Dothan 755.

The other big question is, will the BIOS do the right thing or will it somehow disable the NX bit (or hint to Windows-8 that there is no NX bit in the instruction set?) I am not too knowledgeable about how BIOS configuration works in the PC architecture. According to this application note :

http://msdn.microsoft.com/en-us/library/windows/hardware/hh975398.aspx

No matter what the BIOS does with PAE/NX, it will be overridden and Windows-8 will start if the NX feature is supported by your CPU.

so is it possible to run windows 8 on t42 or not?

I believe so, yes. I have Windows 8 up and running on a MK4 Toughbook CF-29. There are several differences between the PMLV and the PM in Thinkpads, but I believe the fastest PM's should work. I can confirm a nogo on the 735...

I have a PM 755 on the way, and I'll try 8 when it arrives.

Hello,

I don't know about windows 8, but you can install ubuntu 12.04 happily in any T4x machine, since there are non-PAE modded install disks floating around in the net. (I've got my T42 running that way in dual boot mode w/XP).

Regarding the 'PAE enabled' CPUs, an additional problem (besides bus speed) is that BIOS will give an 'unrecognized CPU' message at boot and will not load the updated microcode for them, so you will run 'base' (with whatever launch bugs they happened to have that were fixed lately by microcode patch).

It seems i was talking out of my ar$e on this one. Apparently, no 400 fsb CPU will run Windows 8. 533 fsb version of the PM family will work.

So, anyone have an idea whats the fastest 533fsb PM cpu that works with a T42?

PM780 (2.26 GHz Dothan)...BUT...

Pay $50 for a CPU to cripple its performance by pinmodding and and all of that for the ability of running W8 on a T42...

I wouldn't do it.

I think I have one laying around though. Might be a 770... Gonna try it next time I have one of my t4xs apart...

Also, I wasn't completely wrong. Based on Intels website, the Pentium M 765 is compatible with Windows 8. The 755 and lower are NOT (NX missing). Which sucks because I have a 755 on the way, bugger...

And if anyone is interested, I have 765 for sale

YHPM.

windows 8,..is it?. If NOT get a 2 ghz dothan @ 400 FSB.I got mine from japan some weeks ago for 20 $.It is working fine ....

EVERYONE, hold your horses!

I haven't had time to troubleshoot yet, but my T41p based T4X Frankenpad with PM 765, gives PAE error in Windows 8 setup. Despite the fact that both PAE and NX is supported according to their website.

EDIT: It does NOT work. Intels website has incorrect info on it. The 765 does NOT support PAE and NX. Dont waste your money on the 765, it wont run Windows 8.

Somebody else can be the guinea pig for the 533 fsb PM series. I'm out.

Well, some members already have W8 running on their T43/p units so we know that works...

I'll be in the back row with popcorn and a soda until W8 is replaced with an OS without a Fisher-Price UI...

Did you try to install W8 on another machine and after that just simply swapped the HDD to T41p? I have done this several times with W7, works perfectly.

Well, since I don't have a machine that is compatible with W8 and is close enough hardware wise for the T42p motherboard to still be compatible, no.

And you can install W8, it just doesn't boot afterwards. It is possible to bypass the PAE/NX check by simply upgrading in Windows 7, but it crashes on the first reboot.