DX4 requires 3v, and DX2 is 5v, so they SHOULD have different jumpers. Then again, the closest thing I have to an Aptiva the the IBM PS/1 Tower Model, so no idea, sorry

Problem is there has no voltage regulator in my mainboard.

You'll need an external Voltage Regulator or an Overdrive, I think there's a voltage regulator on Amazon, one sec...

Thanks my friend. I will leave that by dx266

Sorry to reply to such an old thread but I came to report that I have an IBM Aptiva with TYPE F-1 board using a Cx5x86 100MHz and it works just fine.
The settings looks the same as DX4 CPU, and you can use the following guide as a reference:
http://ps-2.kev009.com/pcpartnerinfo/ctstips/ea3a.htm
TYPE F-1 boards are fully compatible with DX4 100MHz, however TYPE C-1 boards are not, in the case of TYPE C-1 you should use an Intel Overdrive DX4 "ODP " CPU.
I hope that helps at least some of you, I will leave it here for further reference.

Regards,
Caio T5 from Byte5

I try to upgrade to a dx4 and I too have some issues... I just open the JP10 jumper (to set to 100MHz) as I've seen in the manual but... It doesn't work (I have some beeps, 2 longs and 4 shorts...)
If you have tips, feel free to share

TY 😀

I have problems with 2144-921 model.
It's F-1 board and should be compatible with amd 486Dx4 processors. Original processor is some kind of Dx4, the heat sink is glued so I don't know the brand. Board has extra voltage regulator.
Problem is board doesn't work with default setup, it had some kind of weird jumper configuration witch doesn't match with any config I could find from web.
Board recognizes original processor dx4-100 if I configure it like the manual says except jp24 has to be in 4-5 or 5-6 otherwise system won't post. However if I put amd 486dx4-100 processor with same config I get DX2-75 in bios, and if I put on intel 486dx2-66 it gets recognized right.
JP10 doesn't change any setting witch ever jumper is configured.

If you need means for voltage conversion I’ve been working on a solution.

Re: Socket 1/2/3 Tweaker (Alpha)

As for settings that the board may not have jumpers for I’ve tried to add them to this device also.

The device is alpha still, I may get around to ordering a prototype eventually. If it interests anyone we can work together to get it tested and past alpha/beta.

It seems that amd dx4-100 is recognized dx2-75 in bios but in dos its recognized as dx4-100.
Next question is, does anyone know what jumpers in j35,36 and 37 do? Manual only says "System board clock speed selection", but doesn't give any config.
http://ps-2.kev009.com/pcpartnerinfo/ctstips/2992.htm
I just tested the board with original intel processor and it only gives 21fps in phills doom benchmark, witch seems bit low. Maybe the graphics card is very slow.

Hmm typical IBM docu's always seem to leave out something back then.
Did not spend much time searching but I did a quick check of the hardware manuals H and I and the other docs too but nothing yet.
You probably already looked but if not You can check here in case I missed something:
under Hardware Installation/Configuration docs: http://ps-2.kev009.com/pcpartnerinfo/ctstips/336_69.htm
under Processors: http://ps-2.kev009.com/pcpartnerinfo/ctstips/336_72.htm

A longer search found this: http://ps-2.kev009.com/pcpartnerinfo/ctstips/cc5e.htm
It does not list the 2144-910 but would think the jumpers be same.....

Thank you very much.
My machine is now in a bit hard to reach spot, but I ordered some cache ram for it, so I will have to get it to my workbench as they arrive. I will then test those settings.

IBM machines are very strange.... mine PC330 DX4 boot wit the Pentium Overdrive 83Mhz ONLY if i put the hard drive in the secondary connector and let the primary IDE channel free....

Indeed ibm machines behave strangely.
I took jumper off j35. Which lead to 40mhz bus speed,so system runs now 3x40=120mhz.
Doom gives now 26fps.
It's a shame that there is no memory options in bios.
I've got 60ns fbm ram installed, if I could just adjust wait states I think it would make a huge difference in tests.

I have a 2144-911 and FSB works as follow
J35 open J36 open J37 open -> 20Mhz
J35 open J36 open J37 on -> 25Mhz
J35 on J36 on J37 on -> 33Mhz
J35 open J36 on J37 on -> 40Mhz