Old emulators of the time ran very well on Cyrix CPUs, due to their short, efficient pipelines. In case of the 686MX / MII the 64KB of unified L1 cache also helped a lot. The MX chip also has a revised FPU which, clock for clock, is a bit better than the one of the old 686. Everything else aside, I would go for the one with the higher FSB. 7