I know it may be somewhat slower than 100.
I currently run a k63 450mhz. I added this disk to the system with an adapater card. Unfortunately, I was having so much trouble using it as a boot device, that I ended up putting my old dma33 drive back in as the primary boot disk. I still use the Maxtor as an auxillary, and it's certainly faster.
Anyway, the real reason I'm looking at this:
I have been planning on eventually ugrading to a new MOBO and CPU. Ideally, Id' go with a DDR setup & Tbird 1.2 (or greater), but I just came across a deal on a partial system with a KT133 board (case/modem/floppy) for around $75. It's only 100mhz front side and UDAM66, but hell, for about $160 I can upgrade my 450mhz to 1ghz. I can use my current PC100 mem and other components. I may just do this for now and wait to upgrade to something really fast in another year or so.