AMD Athlon 64 X2 3800 -vs- Athlon 64 FX 4200

Which one would be "better" in the most basic definition?

I'm either:
- On the web + running a F@H client + listening to music (local or streamed) + other miscellaneous things, or
- Playing games (99% of the time either FEAR or Halo 1/2) - I've paused F@H and stopped most everything else I have running

PS: I have two nVidia 6600 GT cards running one LCD in SLi mode

PPS: I don't want to overclock

[edit] Heh, it's a regular 64 4000 instead, not an FX

not much info about the FX-series, but would guess it is better by design than the X2

for yours need the X2 should be good enough, especially for the games you posted, and isn't that expensive compared to FX.

just be sure about correct sockets between cpu and motherboard

Which core do each of the cpus have? The 4000+ can have either the San Diego or Clawhammer core (San Diego is faster), and the 3800+ x2 can have either the Windsor or the Toledo core (Windsor is faster and uses faster ram).

Either way, the 3800+ x2 is superior. The single thread performance is equal or better than the 4000+, and multitasking is no contest.