390E & 390X CPU upgrade questions...

[richtoy]

Hi

Second post so be gentle with me

I have a 333MHz PII 390E, a 400MHz PII 390X and a 450MHz PIII Dell Inspiron 7500.

Both of the IBMs have 256Mb PC133 SODIMM (2x128Mb) and new 40Gb Hard disks and have been running XP in this configuration for the past 2+ years.

The two IBMs belonged to my kids but they persuaded me to buy them new Acer 2GHz Core 2 Duos so I get left with 3 old laptops

After a bit of research I found this site and the WimBIOS site with lots of info about CPU upgrades so I splashed out and brought 2 brand new 600MHz PIII MMC-2s for £11.00 for the pair off ebay

My plan is to put the 450MHz PIII from the Dell into the 390E and the 2 new 600MHz PIIIs into the Dell and the 390X.

So now the questions: -

I have not found the Ctrl D Hex editor in either of the 390's BIOS's so do I assume that there is nothing to change in either of the 390's BIOS's because they don't have L2 cache or onboard memory?

Even after reading all of the threads, I am still confused about which CPU is supported "as is" by which motherboard. Many links point to the 600 threads but these motherboards don't seem quite the same as the 390X or 390E. Should what I am attempting i.e. a straight CPU swap just work?

I am looking out for a 850MHz PIII for the Dell because I think this will work "as is" so I may have a 600Mhz PIII for the 390E in the future. I presume I will have to make the hardware mod to get the FSB up to 100MHz to get this working in the 390E?

Thanks for your time....
Richard

[tical164]

You will be able to use any MMC-2 CPU in the 390E and X. The problem is that they will clock down 150 MHz since the 390 series do not have Speed Step. So the 850 will only run at 700 and so on. There is a hardware mod which can be done though.

[mechagouki]

Sorry to contradict you tical, but the fastest processor that you can put in a 390E is a Celeron 466mhz mmc-2. Pentium III chips simply will not work in this machine, hardware mods or not. 390X will take up to 850mhz PIII with some bios hacking.

[unrortit]

with the 390x,no bios hacking needed ,but rather cpu hacking to run at 850mhz speeds,otherwise same unhacked cpu will only run 700 mghz.

[I_Am_Banana]

interesting...
why wont the 390E support a PIII processor? I know you can modify the mobo by swapping a resistor to jump the FSB up to 100mhz... so thats not the issue, right?

BTW... I've done this to clock the 300mhz celeron up to 450, but it caused it to overheat, so I clocked it back. Wont a PIII run much cooler, and if I bump the FSB up to 100 shouldnt it work?

[cmarti]

You can use it just follow the same procedure as it would be a 600E.

Read this:

link 1
And this"

link 2

[I_Am_Banana]

hmm, so if I bought a 600mhz mmc2 from a Dell, I should be able to get it to work? That would be one heck of an upgrade

[cmarti]

Remember to post the progress of your project.

[cmarti]

thinkpad 600x@850/nt,95,98,2k,me,xp,vista .

Vista on a 600X??

How do you manage to run it?

[JBUK]

I have been waiting for a long time to do this on my 390X - upgrade the CPU to an 850mhz speedstep model form the 500mhz one installed.
It all went perfectly and mobilemeter showed I was running at 700mhz with stable temperatures. So I then installed the deep sleep L2 cache utility which after rebooting made the cpu run at 866mhz.
But I had to kill the deepsleep off because at the full cpu speed the fan was running almost continually to keep the temperature within limits, even at idle, even with a clean fan, even with good silver paste.
As I do not know a way of upgrading the cooling on this model and I don't want the fan whooshing away at full speed for ages I am just letting it run at 700. It does seem a lot snappier though than the 500 cpu it has replaced so I am happy enough with what I have done.