Not quite a revolutionary cache design, we built a similar L2 is also L3 design 20 years ago in an x86 clone, chip was never released sadly, and of course all the patents have now expired
I probably shouldn't say :-) but those expired patents likely belong to AMD these days
The entire point of the patent system is to encourage disclosure. Patents are by their very nature public information.
If it was 20 years ago the patents shouldn't last much longer...
Cyrix?
On most modern cpus with multiple sockets, it's slower to fetch a L2 line from the other socket than to fetch it from main memory. Was this also true on your system?
these were separate CPUs each with an L2 on the same die - we had a cache-line wide bus directly across the die