R40 CPU upgrade - what's the actual speed increase?

[andreaskew]

Hey guys,

I've read most of the posts on upgrading the CPU in R40s (I've got a Banias 1400MHz R40 2772 model), but none of them really provided any information on how much can you then eventually squeeze out of the Thinkpad. So, if I upgrade to a 1700MHz processor (which, if I understood you guys correctly, is the max I can put in my laptop - right???), how much of a speed/power increase can I expect? I'm already using 2GB of RAM, so obviously cannot do much more in this direction. HDD is a 5400rpm WD, which I'm not too keen on replacing with a bigger/faster one. So, does it make sense to go from 1400MHz to 1700MHz given all the associated risks and costs (ok, the latter probably wouldn't be more than $50 - used CPU, Arctic Silver)...

Thanks a lot!

Best, Andreas

[schen]

I'm not overly familiar with the R40s as I've only worked on one (P M version). However, I would assume that if a machine has the chipset to take a P M, Banias CPU, it would be able to take all of them up through the fastest Dothan of the same bus speed (400mhz in you case). The only glitch I can think of is the older BIOS do not have a few of the last Dothans listed in their microcode (such as the 725a). Which is a long way to say that you can put in any Banias or Dothan CPU that's 400Mhz and doesn't have an "a" behind the model number.

That being said; I would try to keep the upgrade to something that makes sense. Since you've already done the RAM, that's not an issue. Although your machine has a 5400rpm drive, an upgrade there might show some benefits as well with the newer drives having a higher areal density as well as a far larger cache, most tests have shown them to have a much faster throughput. On the CPU front, I'd lean toward keeping an upgrade to the below $50 price-point while making sure that the speed increase is at least two levels faster than what I had (such as the 1.4 to 1.7 jump you had talked about). And I'd definitely try to pick up a Dothan processor while I was in the market since they double the onboard cache to 2Mb.

Of course, all this stuff is a personal perspective thing, but I really think that a combination of those upgrades will keep your R40 viable for some time.