Athlon LE-1640 upgrade question

I decided to do a test this evening. Upstairs I have a Sempron 3000+
based system (~ 2 GHz) that is about 2 years old. Downstairs I have an
Athlon LE-1640 (~ 2.6 GHz) based system that is less than two months
old. (note that earlier I said I have an Athlon BE - wishful thinking on
my part, it's an LE)

I decided to compress the same 50 minute TV show using Nero Recode,
into a 200 Megabyte Nero Digital AVC (h.264/mpeg 4) video file. I
started out with a DVD quality mpeg 2 file.

The Sempron 3000+ leveled off at 17.1 frames per second, while the
Athlon LE-1640 leveled off at 24.33 frames per second. So I got just
over a 42% improvement moving from my old system to my new one.


The new system is an AM2+ based board, and I was wondering what sort
of improvement I could expect from several of the processors out now:

Athlon X2 BE-2400 $35

Athlon X2 6000 $80

Phenom X3 $105

Phenom X4 ??

Anyone familiar enough with any of these to give me a decent
guesstimate on the frames per second numbers I would see with them under
Nero Digital AVC?

I'm mostly trying to figure out if it might be worth upgrading to the
$35 BE-2400 for the next 12 months or so, then going to a quad core
phenom when they have come down in price

Thanks!