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Comment by rbanffy | Hacker News Reader

> What is interesting is the HUGE jump in multi-threaded performance on AMD. Very interesting.

Indeed. Single threaded performance, however, seems bad. Virtual cores most likely share less of the actual core than on Intel parts, allowing one to compete less with the other and get more done. On my i7 laptop, on anything more demanding, I see half the "cores" idling, probably because one is using the actual underlying core while the other is waiting.

Still, while AMD obviously did a good job, it will not make the Intel guys lose any sleep for now.

The server parts are another story. If they manage to reliably outperform Xeons (even if it's only on a per watt basis), it'll be fun to watch.

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>"half the "cores" idling"

Right, thats exactly what happens with Hyper-Threading. If you can fully utilize the physical core, Hyper-Threading can't do much.

It seems the AMD parts can squeeze a little more work from the two threads, judging by the multi-threeaded benchmarks, than competing Intel parts.

Single threaded perf isn't bad, it's just not outstanding. Many of the cases where I care about perf are cases in which the app is multithread savvy.

> Many of the cases where I care about perf are cases in which the app is multithread savvy

Yeah, as would be expected from most people on this site. Sad thing is, there's a bunch of pissed-off gamers right now who were on the hype train expecting Ryzen to be the next big thing in gaming, but it's far from it. Ryzen is great, just not amazing for gaming.

Hyperthreading is not a virtual core and as it doesn't exist as a separate core its hard for it to be idling. Bad analogies make for less than adequate understanding.

They are also called "logical cores" (I think Intel documents prefers "logical" and Sun - they invented the concept - prefers "virtual"). One logical core can appear to be idling to the OS if the parts of the physical core are in use by another (SPARC and POWER go up to 8) logical core (as it's resource starved). It seems, from the benchmarks, the AMD parts have less shared resources between logical cores (or a finer granularity for allocating) than the i7 in my laptop.

Pre Ryzen AMD didn't have anything like hyperthreading. The prior generation had n physical cores wherein each 2 shared a fairly significant chunk of hardware. The new generation of AMD and many generations of intel have extra hardware in each physical core that makes it look and act like additional cores. If I understand it correctly, and please correct me if I'm wrong, it mainly serves to ensure that the core is better utilized in general.

You are correct.

From the benchmarks, it seems a single thread can fully utilize all resources from an Intel processor while it can't on the new AMD ones and that's why their single-thread performance is lower and their multi-thread performance is higher.

We should keep in mind the benchmarks know nothing about the new AMD parts and how to keep all parts of the processor busy.

Server supplies ~60% of Intel's total profits.

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