> Almost every system scales simply vertically, vertical scaling is (to a first approximation) throwing faster hardware at the problem. If you're IO bound you

> Almost every system scales simply vertically, vertical scaling is (to a first approximation) throwing faster hardware at the problem. If you're IO bound you get a faster IO bus (this is not necessarily easy to do, but if you do it the system scales to the limit of it). If you're CPU bound you get a faster CPU. And so on. My interpretation was vertical scaling is within a single node and adding cores or CPUs to a single node is vertical. Multi-core and multi-node really present similar problems, so adding more cores or adding more nodes isn't terribly different from a design perspective. > ...easy to scale horizontally by tacking on additional CPU cores or physical CPUs. If you define adding more cores to a single machine is actually horizontal scaling, then we agree in principle, just not in the definition of scaling.