- 9 months ago
Could Zen 3 really improve IPC by 15%? Zen to Zen+ got ~3%. Care to guess how much Skylake has improved since Sandy Bridge (10 years ago)? 30%. 30% after 10 different microarchitectures and chances for improvment. If each improved IPC by 2.5% (less than the improvement from Zen to Zen+), you would wind up with the 30% improvement, and AMD is trying to get to 15% in a single leap.
That said, this is the easiest time to do it, as they will certainly see everything that Zen left on the table and can work on the lowest lying fruit. But 15% is a lot to improve an already great microarchitecture, lets see if they can do it. I suspect that most of it will be from more efficient threading and they will claim those additional instructions as "IPC". I guess it technically counts, but really isn't why we usually want higher IPCs.
Source: https://www.realworldtech.com/forum/?threadid=185396&curpostid=185439 (I took the root sum of squares of the IPC improvement for the lot).