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Intel 28-core fantasy vs. AMD 32-core reality

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Re: Intel 28-core fantasy vs. AMD 32-core reality

#51

Post by nottorp »

snuxoll wrote: post #41
wmf wrote: post #13

Earlier quoted context omitted.

It's not similar at all. AMD's cores are 10-20% slower while Niagara was 80-90% slower. And AMD isn't intentionally slower; they designed the Zen core for maximum single-thread performance but they just didn't do as good a job as Intel because their budget is vastly smaller.

Zen does a decent job in clock-for-clock performance, huge killer on the desktop is raw clock speed. When you pit a Ryzen chip maxing out around 3.8-4.2GHz (depending on generation and silicon lottery) to an i7-8700K that has a base frequency of 4.7GHz it's pretty obvious which is going to come out on top. Most of that clock hit comes from the 12nm LPP process that AMD is currently using too from what I can tell, low…

Is it such a huge killer outside gaming benchmarks? And even then, the extra power is useful only if you jumped on the 4K bandwagon.

Personally, consider the amount of random crap that i run, I'd rather have more cores. And more importantly, 80% of the performance for 50% of the price is just fine(tm).

Re: Intel 28-core fantasy vs. AMD 32-core reality

#52

Post by zaarn »

wmf wrote: post #10
solomatov wrote: post #2

AMD did a great job with Threadripper, making high end CPUs much more affordable. It's interesting that Intel doesn't lower their prices. What's the logic behind it?

Intel was selling 18-core chips for >$2,400 then when Threadripper came out Intel released the 18-core i9 for "only" $2,000, so that is something of a price drop. Also, Intel's $350 8700K was cheaper at launch than AMD's $450 1800X even though the 8700K is faster in gaming.

Keep in mind that AMD has an inherent advantage: the Zen architecture and Glue.

When AMD fabs a TR2 they have to find 4 good Ryzen dies which are fairly small and they make a lot of them since they are part of the entire lineup. Once they have 4 good dies, they get glued together.

If they wanted 64 cores they'd just have to look for 8 good Ryzen dies, halving their yield compared to 32.

On the Intel side they have to increase the silicon area and then hope that all 64 cores are capable of full core speed in the current setup.

Glueing CPUs together makes it cheap to scale at little cost.

Re: Intel 28-core fantasy vs. AMD 32-core reality

#53

Post by zaarn »

nottorp wrote: post #51
snuxoll wrote: post #41

Earlier quoted context omitted.

Zen does a decent job in clock-for-clock performance, huge killer on the desktop is raw clock speed. When you pit a Ryzen chip maxing out around 3.8-4.2GHz (depending on generation and silicon lottery) to an i7-8700K that has a base frequency of 4.7GHz it's pretty obvious which is going to come out on top. Most of that clock hit comes from the 12nm LPP process that AMD is currently using too from what I can tell, low…

Is it such a huge killer outside gaming benchmarks? And even then, the extra power is useful only if you jumped on the 4K bandwagon. Personally, consider the amount of random crap that i run, I'd rather have more cores. And more importantly, 80% of the performance for 50% of the price is just fine(tm).

The gaming benchmarks are a bit meh since in most realistic builds the GPU will be the bottleneck, not the CPU (unless you buy a 1080Ti with a Ryzen 3 or i3, though in that case all help is lost).

More cores do benefit if you run stuff besides the game, which most people do.

Re: Intel 28-core fantasy vs. AMD 32-core reality

#54

Post by dpedu »

AndrewDavis wrote: post #37
chrisper wrote: post #35

I just recently replaced my old i7 920 in the homeserver with an AMD Ryzen 5 2600. Really like it so far. Price / performance is great. This is my first AMD since probably ever.... The two things I don't like is that their CPUs are pin based. It seemed kind of old fashioned after Intel CPUs. But this is really a minor thing. The other issue is memory compatibility is a bit finicky. Maybe it has to do with the CPU bei…

> don't like is that their CPUs are pin based To me that's a win. If a CPU pin is bent it's typically fairly easy to straighten it. Fixing a bent pin a socket is a massive pain. But it's much easier to protect socket pins with the cover. So there are pros and cons either way.

True, though it is much easier to damage a pin-based CPU in the first place.

Re: Intel 28-core fantasy vs. AMD 32-core reality

#55

Post by bayindirh »

Senderman wrote: post #39
rocky1138 wrote: post #22

Which one of these companies does at better job with free/libre software? I've always had a soft spot for AMD because it's the underdog, but I want to make sure that they are free, too.

If the answer turned out to be Intel, would you overlook the misleading 28-core demo the article discusses?

Intel provides a lot of patches for Linux Kernel, for their hardware, performance counters, and their graphics drivers are open source under mainline. I'm not mentioning their wired Ethernet and other various drivers.

Being one of the top contributors in Linux/OSS/FLOSS doesn't allow them to come clean from their 28-core, inadvertently but conveniently miscommunicated demo.

Re: Intel 28-core fantasy vs. AMD 32-core reality

#57

Post by NullPrefix »

jejones3141 wrote: post #56

For a long time I saved a copy of a publication by Motorola about how Intel played fast and loose with benchmarks in comparisons of the 80386 with the 68020. (I lost it in a move, alas.) Can't say I was surprised to read about the 28-core fiasco.

link?

Re: Intel 28-core fantasy vs. AMD 32-core reality

#58

Post by spacenick88 »

loeg wrote: post #36
dmichulke wrote: post #24

Earlier quoted context omitted.

A slightly OT question: Wasn't that 10-20% before meltdown? Or is there still some similar disadvantage in clock speed per Watt or IPC?

AMD still takes the hit for Spectre mitigations, even if it does not need Meltdown mitigation. And I'm not sure it's possible to fairly discount Intel's performance with meltdown mitigations applied. I think the impact will vary depending on workload.

Afaik not, at least on Linux the mitigations are turned on as needed by CPU ID data

Re: Intel 28-core fantasy vs. AMD 32-core reality

#59

Post by xxs »

snuxoll wrote: post #41
wmf wrote: post #13

Earlier quoted context omitted.

It's not similar at all. AMD's cores are 10-20% slower while Niagara was 80-90% slower. And AMD isn't intentionally slower; they designed the Zen core for maximum single-thread performance but they just didn't do as good a job as Intel because their budget is vastly smaller.

Zen does a decent job in clock-for-clock performance, huge killer on the desktop is raw clock speed. When you pit a Ryzen chip maxing out around 3.8-4.2GHz (depending on generation and silicon lottery) to an i7-8700K that has a base frequency of 4.7GHz it's pretty obvious which is going to come out on top. Most of that clock hit comes from the 12nm LPP process that AMD is currently using too from what I can tell, low…

>i7-8700K that has a base frequency of 4.7GH.

That's not base at any rate, you can't get all cores at 4.7Ghz stock, 4.7 is a turbo-boost single core. No way you get that w/o a pretty decent cooler on a non-delidded CPU unless happen to have a chip that requires no extra voltage at all.

It's true that many games are predominantly single core, though but it's likely to get a single core 4.5Ryzen as well.

Re: Intel 28-core fantasy vs. AMD 32-core reality

#60

Post by paulmd »

dmichulke wrote: post #24
wmf wrote: post #13

Earlier quoted context omitted.

It's not similar at all. AMD's cores are 10-20% slower while Niagara was 80-90% slower. And AMD isn't intentionally slower; they designed the Zen core for maximum single-thread performance but they just didn't do as good a job as Intel because their budget is vastly smaller.

A slightly OT question: Wasn't that 10-20% before meltdown? Or is there still some similar disadvantage in clock speed per Watt or IPC?

Meltdown mitigation doesn't affect consumer workloads much. Database and server workloads are hit a lot harder.
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