Thinkpads Forum

I'm playing around with two "bought for parts" thinkpads:
a R52 and T40.

The R52 has a Pentium M 725A CPU listed as having a 400MHz bus. The RAM on this machine is DDR2 (PC2-5300).

The T40 has a Banias CPU and DDR (PC2100) RAM.

I'm assuming the 2 CPU's are compatible (both have same socket and 400MHz bus speed) although the 725A has a 2MB L2 cache so is the better one.

The RAM obviously is non compatible (slot in different place )

Let me know if I've missed anything.

Thanks.

The R52 never came with a Pentium Banias, and it is possible that the BIOS will not support it. Functionally it should work as you've mentioned, but it's one of those things that you're just going to have to try and see if it works, unless you can find someone here who has done it. Technically it's a downgrade from a Dothan, so it's not likely someone has tried it. I beleive the Pentium M 725a Dothan may have a problem in the T40 because of the 'A' stepping for the same BIOS support reason mentioned above. Again, try it.

Thanks Harry. I've fitted the 725A to the T40 board and the BIOS supports it

Awesome, another CPU that works. Thanks for the information.