5 ms·
After looking at this closer, what they are comparing is single threaded performance of the Skylake Xeon 8176. At 28 cores and 56 threads, that watts per threa
by kbenson 8y ago
After looking at this closer, what they are comparing is single threaded performance of the Skylake Xeon 8176. At 28 cores and 56 threads, that watts per thread or core value starts to look somewhat comparable, given Apple's low core count (compared to that desktop CPU) and that they might not run the Vortex (2x) and Tempest (4x) cores at the same time(?).
So, I think it's both a matter of comparing Apples to Oranges (ugh, I would use a less confusing analogy if one came to mind) in that the types and usage and number of cores are different, and also just fairly impressive that they can get that much single threaded performance out of the chip.
- frou_dh 8y agoIIRC one of the changes from the A10 to the A11 was that the different sized cores started being able to run simultaneously. Apparently the smaller Tempest core from the A12 is being used as the main core in the new Apple Watch. Talk about, uh, synergy.
- wintercharm 8y agoYeah. The S4 Apple watch SoC is actually using Two Tempest (LITTLE) cores. Pretty awesome, if you think about It. That little watch is more powerful than it appears.
- jfb 8y agoThe craziest thing is how close they get at 3W. That's the part that's staggering. What could Apple do with, say, laptop thermals? Desktop thermals? The mind creeps closer to boggling.
- FireBeyond 8y agoIt's not that staggering. Use the above example. It's comparable to one thread of the 56 thread Xeon 8176. That server CPU has a TDP of 165W. That's 2.95W per thread. So pretty much entirely on par with Apple.
- kbenson 8y agoWell, except that hyperthreads are not the same as cores, so it's not quite equivalent. My understanding is that the two hyperthreads for a core share some execution resources, but are able to run in parallel for other resources. That means some workloads won't benefit much at all, others will benefit greatly, and the usual case is somewhere in-between. Also, I think I've heard people here noting how hyperthreading causes some workloads to go slower (possibly from CPU heat throttling? Dunno) so some people disable it in the BIOS first thing. So the truth is likely somewhere between 2.95W/thread and 5.90W/core (assuming 165W is even correct, there's comments here noting while AMD and ARM quote max, Intel quotes operating average...).
- ianai 8y agoUser interface drawing/responsiveness depends most on single core performance.
- jfb 8y agoBut that’s not a useful comparison, because you can’t run a Xeon at 2.95W. There is a floor wattage that the processor simply cannot go below.