After my last post comparing the K6-2+ and K6-III+ cores at the same 500MHz frequency, I wondered if it is better to run a K6-III+ 500 or a K6-2+ 550 MHz in my system to obtain the maximum performance. So the basic idea is to know if gaining 50MHz is better than gaining 128KB of L2 cache.

So here are my 2 contenders as seen by CPU-Z. The K6-2+ is probably the easiest chip to find if you build a retro-K6 system.

And here are the scores from 3DMark 2001 SE. Before the test I was sure the 50MHz increase would be the dominant factor, as it represents a 10% increase. From the previous test we knew that the 128KB increase at a fixed 500MHz speed yielded a 6% performance increase.

Surprisingly, the K6-2+ obtained a score of 2001 and the K6-III+ a score of 2016! So the cache increase actually outweights (slightly) the frequency gain. In practice I doubt that you will feel any difference, so if you have one chip or the other and wonder if you should upgrade, just stay with the one you already have :)