Cyrix' M2 was, on paper, quite an improvement over the M1R that the IBM 6x86 P200+ used. This because the M2 is made on 350nm instead of 650nm and thus uses a lower core voltage which causes much less heat generation. Despite this, the increased L1 cache (to 64KB instead of 16KB) the results in the benchmarks are not shocking because it still lacks a decent FPU. Doom doesn't seem to fly but the faster the CPU gets, the harder it will be to get a higher score with Doom. The PCI bus and Matrox Millenium 4MB PCI I use for the Doom benchmark is nearing it's limits. It isn't surprising that Doom runs slightly better on the old 6x86 P200+ (M1R) because this CPU uses a 75MHz FSB and 37,5MHz PCI bus.

On the other side: when benchmarking the CPU's in Windows I removed the Pentium MMX 200MHz and installed the Cyrix 6x86MX PR200 and immediately noticed that Windows ran much more smoother. I guess the CPUMark '99 score will represent the performance in Windows quite much . MDK also seems to run a lot better compared to the 6x86 P200+.
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Similar to the Cyrix 6x86MX PR200 but then a tad faster. This one clocks at 187MHz using a 75MHz front-side-bus so it's only 21MHz faster than the PR200 mentioned earlier. Luckily the increased front-side-bus will compensate for the slightly increased clock frequency and increase overall performance after all. > Read more

Technically this is a Cyrix CPU but IBM sold them under their name as well. I like the dark looking heat spreader that just sits on top of the 'die' (the core). You can look under the heat spreader and actually see the 'die' along with some SMD chips. Somehow that reminds me a lot of the AMD K6-2 (which looks pretty much the same if you remove the heat spreader) especially because the bottom of the CPU is just identical. > Read more