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Does 1.25x performance at the same power refer to clock speed? Does that mean that we can expect 5 Ghz in Ryzen 3000?
by piinbinary 8y ago
Does 1.25x performance at the same power refer to clock speed? Does that mean that we can expect 5 Ghz in Ryzen 3000?
- clircle 8y agoI don't know a lot about CPUs, but my guess is No. That just sounds too good to be true. I'd love to be wrong though.
- m_mueller 8y agoLook up Dennard Scaling and how it broke.
- dragontamer 8y agoDennard Scaling would have been 2x clock-rate from an improved node. 1.25x scaling from an improved node is way, way, way worse than Dennard Scaling of the past. Intel Pentium III Coppermine (1999) went from 733 MHz on the 180nm node to Pentium III Tualatin (2001) 1400 MHz on the 130nm node. THAT was Dennard scaling. Today, we "only" get double-digit gains from an improved process node. Dennard Scaling was triple-digit gains. Furthermore, most CPU makers focus on the power-saving aspects (which seem to be scaling somewhat well still).
- m_mueller 8y agoIf you look at GP's question, (s)he was asking about 5Ghz in Zen2. Since Epyc 1 is ~3Ghz, a 1.6x increase in clock speed for a ~1.4x smaller process size (AFAIK "7nm" is overselling it compared to 14nm) to me smells like Dennard scaling and thus cannot be expected anymore (if you disregard tricks like turbo boost where a bunch of hardware gets disabled such that the rest can be boosted).
- Dylan16807 8y agoThey're asking about a 1.25x increase on a 1.4x smaller process. Even if you completely ignore boost clocks, the 1900X has a base clock of 3.8GHz, so interpret it as "4.75GHz base clock on a non-Epyc part" if you must. But I don't think you should ignore boost clocks. They're not a trick to make the silicon seem more capable. The silicon really is that capable and boost clocks are a trick to cap power draw. It's entirely fair to look at the 4.2 boost clock on the 2990WX and conclude that the silicon is capable of 4GHz under non-exotic conditions.