the KT7A and Kt7 : Three 168-pin DIMM sockets support up to 1.5 GB PC100/PC133 SDRAM module. If you are using windows 95/98/ME. 256 mb is enough, you may find taking one of the 128's out will increase performance slightly. If it is windows 2000/XP, 256 is fine, 512 is finer . Anything more then that is not really needed unless you are into graphic design.
Pentium 3 1000 @ 1100 ( windows 2000 server), Abit bx-133, 256 Mb Mushkin Rev.3 cas 2-2-2, ATI Radeon
AMD Thunderbird 1.4 @ 1.63 (24/7) IWILL KK266R , Corsairs pc 150 cl2, Leadtek GeForce 3