Best program for reencoding vidoes (DIVX 3 to DIVX 5) on the Athlon 64?

Hello

What is the best program for re-encoding vidoes (DIVX 3 to DIVX 5) on the Athlon 64?

I am currently using VirtualDub 1.51 (I think) on an AMD Athlon 64 34500 (2.2Ghz) OC'ed to 3800+ (2.4Ghz) I ahev dual channel Corsair 2-2-2-5 1T memory running at 2.5-3-3-9 1T OC'ed to 876Mhz and I am using the DIVX 5.1 codec and it is about the same speed at encosdng as my brothers 2.8 P4 with HT (Northwood).

I know that VirtualDub is not optimized for the Athlon XP or Athlon 64 (because the developer hates the register limitations of the A64 hardware).

I am first extracting the audio, then converting the video then re ading the audio channel.

Q1) Is there a better tool for re-encoding videos for the A64 that isn optimized for the A64?

Thanks in Advance

dont reincode!! why?!

Divx 3 has problems with fast movement where divx 5 does not.

but reincoding will only make problems worse, since the video is alreay in divx3...