I'm assuming you are talking about the x2 dual core cpus?
If so, the 3800+ and the 4200+ (Manchester core) share the same everything. They have the same core structure and chip architecture. The 4200+ runs at 2.2Ghz per core, where as the 3800+ runs at 2.0Ghz per core.
With any decent motherboard and a little bit of reading, you can bump the 3800+ up to 2.2Ghz. I have a friend that has one at 2.45Ghz on the stock heatsink and fan.*
The 4400+ (Toledo core) on the other hand, is different. It has a level 2 cache of 1Gb, where the 3800+ and 4200+ have 512Mb.
How much of a difference you will see between the chips playing games is subjective. Personally, I would invest more into a quality gpu, and save a lil' coin on the cpu.
* I am by no means telling you to get a cpu and overclock it, I'm simply stating it can be done. I opted for the 3800+ due to the fact I don't believe I'm going to see a huge difference in 200Mhz. If I feel I'm missing something, I'll bump it up a few hundred Mhz.
BTW, going with the 3800+ is far from a "downgrade".
Edited by hatr3d, 05 May 2006 - 06:39 AM.