when DOOM first came out I only had a 386SX-25 to play it on and I would have loved 12fps (which is also much better than ADOOM on my 50MHz 030)
The disadvantage of those Cyrix chips compared to a real 486 is only 1KB of cache instead of 8KB
yay look what I scanned:
http://www.hyakushiki.net/junk/cyrix.gif