Originally Posted by M1thrandir
Celeron is older than the Pentium M and is not nearly as good as it. Dont be fooled by the 1.8Ghz. Like when you see a Pentium 4 at 3.6Ghz and look at the Pentium M and see that it is like 2.0Ghz or something like that, dont worry. I forgot what the exact ratio is, but that 2.0Ghz Pentium M is going to be the same speed as the P4 or faster. It has been discussed quite a bit on the forums before so you might want to try a search and see what you come up with. The M is also designed for mobility. So ya, I would go with the M. And as Keane said, you get dedicated graphics rather than the crummy integrated graphics. Hope this helped and try searching the forum and you will get more exact info.
The Celeron-m is no older than the pentium-m, they're the same cores from the same batches, it's just the Celeron-m's are the pentium-m's with failed caches and damaged speedstep, hence the Celeron-m's have half the cache and lack the enhanced speedstep. As mentioned the lack of cache isn't too big an issue as the P-m isn't heavily reliant on it like the Northwoods were, but losing the enhanced speedstep means the celeron-m isn't as power efficient.