EggXpert

I have a Thinkpad X61s and wanted to upgrade the processor from L7500 1.6GHz 800FSB 4MB L2 Cache. Is it possible to upgrade this? Any suggestion on what processor is compatible, that is if the upgrade the possible? What socket does it have?

My configuration model is 7668-CTO.

Thank you. 

Theoretically yes, but it's a lot of trouble to get done. The 'safest' way to upgrade is to do it to the highest performing processor used in those specific model notebooks. The reason being is that if you try to get the current best processor that's out, there's a good chance it wont work with the computer.

So by looking at the same laptops and seeing what the best processor they use is, you can buy one and upgrade it.

In short, it's hard to do, it'll void your warranty, and might not work.

Any socket compatible CPU can be plugged into your laptop.  Will it work?  Probably not.

Laptops suck when compared to desktops in their BIOS and hardware specs generally limits them to a small set of possible CPUs. (typically two).

Obviously you can see what upgrades came with your laptop to tell what for sure will be compatible.  Anything else may pull more power than your laptop is designed burning out traces and rendering your laptop into a serving tray. 

Regardless.  An upgrade is not worth it as the slight increase in speed and if you are fortunate L2 cache, results in little perceived speed.  If your laptop is over three years of age, or it is getting time to replace a $175 battery it is time for a new one [unless you have a very expensive >$2,000 ultralight or desktop replacement].  That is the best "upgrade" for the buck you can do.  I probably would simply ask why you are dissatisfied with an X61s?  It is a great laptop!  If after a year or so it seems slow, why not back up the drive, and data, download the latest drivers, and clean install the OS?  That will definitely speed it back up.

I've got an X61 with a standard voltage processor at 2.0 GHz. Doing some research before the purchase it sounded like the only difference between the X61 and the X61s was the low voltage processors in the X61s notebooks. If that's the case, then you should be able to drop in a normal voltage processor with a higher clock speed.

Kind of ironic though, since you paid more for the low voltage processor in the first place (probably by several hundred dollars). From the cost of the new CPU and the risk of damaging the system during installation I'd say just leave it be. Do whatever work that demands more performance on a desktop and keep the reliable ThinkPad as it is for less demanding and mobile work. Cheers!