Intel Doubles Down on Doubled Up Xeons for HPC | Hacker News Reader

Intel Doubles Down on Doubled Up Xeons for HPC

nextplatform.com

33 pointsrbanffy24 comments

The problem with Intel is that they are too worried about competing with themselves. Every bit of their server pricing is designed to prevent people from finding a "bargain". That works really well when you're only competing with yourself, but falls down when outside competition finally arrives.

Right now, the AMD Epyc is the only game in town in terms of I/O bandwidth if you want to build a single-socket box that can serve 200Gb/s from NVME to the network. Part of this is because Intel has categorized heavy IO as something where they want to force you to multi-socket, so they limit the PCIe lanes to 48 lanes per socket (which is enough for only about 150Gb/s).

So, I'm really looking forward to seeing where this chip falls in their pricing structure, and whether or not it has more than 48 lanes of PCIe wired out of the chip.

This reads mostly like a pretty PR-fed puff piece version of the announcements of the Cascade Lake MCM that HN discussed last week [1], and again the Anandtech piece [2] is more interesting as well as more skeptical. Granted it hasn't been out for deep 3rd party testing and inspection yet, but from what was announced after chewing on it a week I think this still feels like a desperate rapid response move from Intel being caught off guard rather then the result of a long planned strategy. It feels too much like they took what they could given yield and TDP and simply applied a ton of glue they already had until they kind of worked together in a single one-off product that could at least produce headline numbers more competitive to AMD. No EMIB, no range of products up and down the spectrum with smaller Xeon modules designed for combination, just this ginormous 300W one-off with UPI. In fact this article seems to have a bit of new info on that:

>*"that leverages one of the three UltraPath Interconnect (UPI) links to hook the two physical chips together to create what essentially is a 48-core socket with 12 memory controllers"

If that's correct and it's 3 UPI, then presumably it'd be the square config so unlike a normal 4P system each processor does not necessarily have a direct link to all others, they may have to go through multiple hops. It definitely would not be "essentially a 48-core" at all since it'd complicate memory access patterns significantly wouldn't it? If that's the layout the potential for benchmark cherry picking and specific optimization that isn't applicable to other workloads seems even higher then normal.

AMD got a leap on Intel last with x86-64 because they didn't want to do that on the desktop, maybe MCM will turn out to be something a little like that (though less dramatic) as well given the realities of increasing difficulties in large single chip fabrication. It'd be interesting if internally Intel is rethinking that but this doesn't seem like "doubling down" so much as a first scramble.

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1: https://news.ycombinator.com/item?id=18389373

2: https://www.anandtech.com/show/13535/intel-goes-for-48cores-...

> If that's correct and it's 3 UPI, then presumably it'd be the square config so unlike a normal 4P system each processor does not necessarily have a direct link to all others

Yeah but their target isn't to compete with a 48 core monolithic CPU it was to compete with AMDs EPYC CPUs which have even less uniform connectivity between sockets (3 per used for in socket interconnect and only 1 used to connect to the other socket). Unfortunately for Intel AMD is still going to be a step ahead this generation with the chiplet + IO module architecture IMO.

If it had been a considered move, planned well in advance they would have designed some Xeon dies to use EMIB interconnects rather than making due with the designs they had on hand.

[1]https://www.intel.com/content/www/us/en/foundry/emib.html

Unless they consider this a transitional generation to future MCP processor modules.

Launch early, assess market fit and plan accordingly. Intel did differently with Phi and it didn't quite work the way they (and I) expected.

Also, this MCM approach is a common Intel strategy. They did it for early dual core CPUs (Pentium D) and again with early quad core CPUs (e.g. Q6600 was basically two E6600 chips).

> It definitely would not be "essentially a 48-core" at all since it'd complicate memory access patterns significantly

My belief is that it behaves similarly to a 4-way 12-core machine using less real estate for the CPU. Even though memory will occupy the same amount of space, I suspect we may see it on high-end workstation-class machines by the likes of Supermicro and Gigabyte.

Rajeeb Hazra, corporate vice president and general manager of Intel’s Enterprise and Government Business Group was asked about AMD’s upcoming Rome chip with the Zen 2 microarchitecure, saying that the company was confident in the “unparalleled assets” that are driving the evolution of Intel’s products, both hardware and software. “Those assets are not just around cores and frequencies and things like that of the past, but around how we put a diverse set of IP together, how we actually enable standards in the ecosystem … and harness the energy from both hardware and software out there on those platforms,” he said. “So, yes, in summary, I’d say we are going to be extremely competitive and drive to this next phase of converged computing for HPC and AI with the innovations we have planned and I’m very confident that that will happen in a way that our customers can continue to bank on us for the leading technologies and solutions they need to run their businesses.”

For some reason this answer reminds me a lot of Steve Ballmer's (in)famous response when asked about the iPhone.

My experience with 40 core Xeons is that the memory bandwidth makes it too difficult to get really good performance out of them as it is.

It depends on your problem. If your workload spends a lot of time waiting for a cache miss, halving the number of threads and spreading them across cores will increase available cache for each thread and increase your throughput substantially. If the working data is larger than the cache, additional memory channels will make your life much better, so getting the CPU with the most memory interfaces will be more important than getting the one with more cores, threads, SIMD pipelines or GHz. I would say that serving web requests from one of these or simulating quantum computers is not the best cost/benefit you'll find, but if you need to do something like CFD, it seems like a good match.

I may be off a bit, but the last two generations of Xeon Phis could emulate a general 10-12 qubit quantum computer without leaving the HBM memory on the processor module and hitting the external memory buses. I'm curious if anyone has tried that.

34 gigabits/sec/core isn't astounding by any means but unless you went looking for more cores as a performance solution to your already io-bound workload it should be plenty.

Surely this is the path of the new New Mac Pro (2019 edition)

As soon as Thunderbolt 3 is opened up I would rather have an EPYC 2 + Vega 7nm in the next Mac Pro.

Thunderbolt 3?

Surely it will be 4 so they can run at least one 8k display, if not two.

Well, the may be the original plan, since TB has been synced to PCI-Express. But Intel doesn't have plans for PCI-E 4.0 yet, at least not on their roadmap. May be they will go straight to 5.0, we don't know. But they key is an open standard.

well, looks like they finally have to compete again.

Because they can charge at least 4x the prices.

If you get 4 times the throughput for 4 times the price, but can get away with single socket instead of 4 socket at half the energy, space and cooling budget of the similar 4 socket solution, it's still an impressive gain.

Processor is a relatively small part of the TCO of a server. As of late, memory and storage have been as impactful in the total upfront cost as processors used to be, if not more, and space and cooling dominate the ongoing costs.

Agreed. I wonder just how stymied tech has been by memory costs and tech. Recent years have seen an increase in cores but not much in ram. We should be talking about persistent storage at ram speeds or closer fractions of terabytes of ram available for workstations.

I hope the Intel gets nationalised so that affordable computing power could be released to the mases. At present only huge corporations can afford it and this should change.

Against my better judgement I will reply to this. At first I was hoping you were being sarcastic but I am not so sure.

the amount of computing power available to anyone this day and age is astonishing and what keeps Intel's pricing in line is the competition from all the other manufacturers. If anything there is such an abundance of power that many fail to understand just how much can be done at lower levels instead of assuming having the most is the best solution

Look at the history of e.g. International Computers Limited (ICL) to see what nationalised computing industry was like. Slow pace of development, product development interference by government, and high prices. It's personal computing and capitalism that have made computing so available and affordable, and pushed miniaturisation to its limits. For example, just look at AMD's threadripper CPUs, or any modern GPU. A ridiculous amount of compute capability at a very affordable price, and pretty low running cost. I laugh to think about a nationalised industry having the drive and business sense to invest in such advancements, and then capitalise upon them to make a decent profit. They are run by bureaucrats and beancounters, and avoid rocking the boat at all costs. A bit like the present-day Intel maybe, which got into a safe zone where they could keep pushing out more of the same without really putting in much effort. You wouldn't want revolutionary products to cannibalise your existing business, after all.

Nationalized computing would be the equivalent of everyone being stuck with a Raspberry Pi 3 for the past 5-10 years.

I don't get this line of reasoning that revolves around the idea that nationalizing corporations is this magic incanation that makes all dreams come true.

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