groo :
I've never swapped a laptop CPU, but it some cases It would save hundreds of dollars. if its not going to save you much, I wouldn't bother.
the big problem is dealing with the heat sink.
Replacing a standard pin-grid-array (socketed) laptop chip isn't really any harder than replacing a desktop chip. There are three hard things in replacing a laptop CPU though:
1. Making sure your laptop's BIOS will support a newer chip. If your laptop didn't have a specific chip as a purchase option at some point, chances are about 100% that it will not support it, even if it's just a die shrink or a different stepping. Welcome to the don't-mess-with-the-black-box world of OEM computers...
2. Getting a suitable processor to replace your existing one. You can generally find high-end Core 2 Duo notebook processors easily and also Celeron Ms but lower-end C2Ds, Pentium Dual Cores, and about any socket S1 AMD mobile chip is hard to impossible to find.
3. Getting the computer apart enough to remove the heatpipe and heatsink arrangement without breaking the cheap plastic nubs on the parts that snap closed to hold the notebook's case together.
Once you have the new processor in hand, the BIOS will support it, and you have the computer apart enough to remove the heatsink and heatpipe assembly, it's almost identical to removing and replacing a desktop CPU. The only differences are that you have to unscrew the heatsink/heatpipe assembly and possibly fan instead of unclamping them and there is a screw that controls the clamping of the ZIF socket rather than a lever. The rest is the same- pick up old CPU, take some solvent to the heatsink and remove old thermal grease, reapply new thermal grease, insert processor, clamp the socket, then reattach and refasten the heatsink. I have changed several notebook CPUs and this is the procedure I used on all of them. However, note that most LV and all ULV processors are ball grid array units and have no socket- they are directly soldered to the motherboard like a chipset is soldered to the motherboard. They are most certainly not replaceable.
with memory, on the other hand, it made to be simple, and a pretty significant savings[/quotemsg]
Sometimes it is simple and sometimes less so. Dell in particular does not make it easy to replace memory as the #1 DIMM slot is underneath the keyboard on almost all models. If you know it's there and have a service guide PDF open to locate the screws and pry points, it adds maybe two minutes to the job, but if you don't have the guide or have never worked on Dells, it adds quite a bit of trouble. Some laptops even have some memory soldered onto the motherboard and it is not replaceable. The 12" PowerBooks and the Dell D400 series come to mind as they are set up that way and only have one user-replaceable DIMM.