好像听说都是单倍速度的吧？只是加大了什么内存而以。

Popular speculation suggests that SNK made several changes to the CD hardware to end up with the CDZ, with the most prominent rumor being that they increased the CD-ROM drive speed from 1x to 2x. The truth, however, is that the CDZ had a larger amount of cache. Though the CD-ROM motor in the CDZ may have been more efficient than the one in the original, it was still a 1x speed CD-ROM.

WIKI上面也是这个说法了，CDZ只是增大了缓存，还是单倍速的。