> which allows heavily interactive programs to run across multiple machines with cache coherency fully guaranteed in all respects. Cache coherency gets increas

> which allows heavily interactive programs to run across multiple machines with cache coherency fully guaranteed in all respects. Cache coherency gets increasingly expensive with scale. At some point, the costs exceed the benefits. The location of point depends on lots of things, but if you're on the other side.... Also, there are many kinds of coherency.