Plenty of people are using XP2100+ on A7V133. Works best in Jumper mode. In Jumper Free mode, you would have trouble running a 133 Mhz FSB (assuming you have PC133 memory).
XP2100+ is a Tbred B and is good for overclocking to 2.1 to 2.2 Ghz (~XP2800+) or higher, even on your old mobo.
Check the ASUS news group, alt.comp.periphs.mainboard.asus, to read about other A7V133 owners using Tbreds and overclocking Tbreds.
The flexibility that has been built into the Tbreds (and Bartons) is impressive.
I had an XP2400+ (actually XP1700+ with the multiplier mod'd but a stock XP2400+ works too) running in an old Abit KT7. That's a KT133 (no "A") mobo. The processor defaults to 20 x 100. That's stock speed (2000 Mhz) for an XP2400+ but notice the low FSB speed of 100 Mhz.
Tbreds have a multiplier remapping mode which makes this possible on motherboards who's multipliers normally only go up to 12.5x. Multipliers of 15x, 16x, 16.5x, 17x, 18x, 19x, 20x, 22x, 23x, and 24x are available even on 3 year old motherboards.
<b>[ADDITION]</b>
p.s. Just set the A7V133 to Jumper mode and set the multiplier to whatever you want (see multiplier remapping table below) then set your bus speed, either 100 Mhz or 133 Mhz. At 133 Mhz might have to run slightly overclocked (15 x 133 = 2000) but it's not a problem for a Tbred B. Some mobos have trouble with the 13x, 13.5x and 14x remaps so just wanted to warn you.
You could just use an XP2400+ and then nothing need be overclocked.
Multiplier Remap Table
<pre>5 ----> 13x (doesn't work on some mobos)
5.5 ----> 13.5x (same)
6 ----> 14x (same)
6.5 ----> 21x (same)
7 ----> 15x
7.5 ----> 22.5x
8 ----> 16x
8.5 ----> 16.5x
9 ----> 17x
9.5 ----> 18x
10 ----> 23x
10.5 ----> 24x
11 ----> (reserved)
11.5 ----> 19x
12 ----> (reserved)
12.5 ----> 20x</pre><p><b>56K, slow and steady does not win the race on internet!</b><P ID="edit"><FONT SIZE=-1><EM>Edited by phsstpok on 08/20/03 02:06 PM.</EM></FONT></P>