[SoLiDUS]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>The most obvious difference lies within the cores. The K6 line was based on powerful Integer performance; this is also a good reason for them to develop 3DNow! as 3D games became more and more Floating-point intensive AMD had to find a solution. 3DNow! is unfortunately not supported in the many of the best applications and games around. For example, I blieve Half-Life rocks, but without 3DNow! you need a much higher clocked CPU to perform the same tasks as an Athlon. An Athlon 500 would be just as fast as a 750MHz K6-III, but this will never happen because of the K6 core is not pipelined to that extent.

One of the main differences between the K6 and the K7 core is the highly pipelined FPU of the K7. The K6 has a low-latency FPU, but the K7 has 3 pipelines within its FPU. The K6 core has a peak FP performance of 1 operation per clock, while the K7 has a peak of 3 FP calculations per clock. There are many different types of FP calculations, and the K6 core uses less cycles per calculation, but the K7 has the pipelines to support the higher latency of a FP calculations.
<HR></BLOCKQUOTE>


FPU means floating point unit..

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Short for floating-point unit, a specially designed chip that performs floating-point calculations. Computers equipped with an FPU perform certain types of applications much faster than computers that lack one. In particular, graphics applications are faster with an FPU.

Some microprocessors, such as the Intel 80486 and Pentium, have a built-in FPU. With other microprocessors, you can usually add an FPU by inserting the FPU chip on the motherboard.

Floating-point units are also called numeric coprocessors , math coprocessors , and floating-point processors
<HR></BLOCKQUOTE>


Hope this helps you understand the difference between both processors.. and as a final gift to you, a website comparing the athlon (k7) with a k6-3 :
http://www.hiphardware.com/editorials/K7/index.shtml