Explaining the Jump to Using HCC Silicon

When Intel makes its enterprise processors, it has historically produced three silicon designs:

  • LCC: Low Core Count
  • HCC: High Core Count (sometimes called MCC)
  • XCC: Extreme Core Count (sometimes called HCC, to confuse)

The idea is that moving from LCC to XCC, the silicon will contain more cores (sometimes more features), and it becomes cost effective to have three different designs rather than one big one and disable parts to meet the range. The size of the LCC silicon is significantly smaller than the XCC silicon, allowing Intel to extract a better production cost per silicon die.

Skylake-SP Die Sizes (from chip-architect.com)
  Arrangement Dimensions
Die Area
LCC 3x4 (10-core) 14.3 x 22.4 322 mm2
HCC 4x5 (18-core) 21.6 x 22.4 484 mm2
XCC 5x6 (28-core) 21.6 x 32.3 698 mm2

In the enterprise space, Intel has each of the three designs throughout its Xeon processor stack, ranging from four-core parts (usually cut down versions of the LCC silicon) all the way up to 28 core parts (using XCC) for this generation. The enterprise platform has more memory channels, support for error correcting and high-density memory, the ability to communicate to multiple processors, and several other RAS (reliability, accessibility, serviceability) features that are prominent for these markets. These are typically disabled for the prosumer platform.

In the past, Intel has only translated the LCC silicon into the prosumer platform. This was driven for a number of reasons.

  • Cost: if users needed XCC, they had to pay the extra and Intel would not lose high-end sales.
  • Software: Enterprise software is highly optimized for the core count, and systems are built especially for the customer. Prosumer software has to work on all platforms, and is typically not so multi-threaded.
  • Performance: Large, multi-core silicon often runs at a low frequency to compensate. This can be suitable for an enterprise environment, but a prosumer environment requires responsiveness and users expect a good interactive experience.
  • Platform Integration: Some large silicon might have additional design rules above and beyond the smaller silicon support, typically with power or features. In order to support this, a prosumer platform would require additional engineering/cost or lose flexibility.

So what changed at Intel in order to bring HCC silicon to the HEDT prosumer platform?

The short and shrift answer that many point to is AMD. This year AMD launched its own high-end desktop platform, based on its Ryzen Threadripper processors. With their new high performance core, putting up to 16 of them in a processor for $999 was somewhat unexpected, especially with the processor beating Intel’s top prosumer processors in some (not all) of the key industry benchmarks. The cynical might suggest that Intel had to move to the HCC strategy in order to stay at the top, even if their best processor will cost twice that of AMD.

Of course, transitioning a processor from the enterprise stack to the prosumer platform is not an overnight process, and many analysts have noted that it is likely that Intel has considered this option for several generations: testing it internally at least and looking at the market to decide when (or if) it is a good time to do so. The same analysts point to Intel’s initial lack of specifications aside from core count when these processors were first announced several months ago: specifications that would have historically been narrowed down at that point in previous designs if they were in the original plans. It is likely that the feasibly of introducing the HCC silicon was already in process, but actually moving that silicon to retail was a late addition to counter a threat to Intel’s top spot. That being said, to say Intel had never considered it would perhaps be a jump too far.

The question now becomes if the four areas listed above would all be suitable for prosumers and HEDT users:

  • Cost: Moving the 18-core part into the $1999 is unprecedented for a consumer processor, so it will be interesting to see what the uptake will be. This does cut into Intel’s professional product line, where the equivalent processor is nearer $3500, but there are enough ‘cuts’ on the prosumer part for Intel to justify the difference: memory channels (4 vs 6), multi-processor support (1 vs 4), and ECC/RDIMM support (no vs yes). What the consumer platform does get in kind is overclocking support, which the enterprise platform does not.
  • Software: Intel introduced its concept of ‘mega-tasking’ with the last generation HEDT platform, designed to encompass users and prosumers that use multiple software packages at once: encoding, streaming, content creation, emulation etc. Its argument now is that even if software cannot fully scale beyond a few cores, a user can either run multiple instances or several different software packages simultaneously without any slow-down. So the solution to this is rather a redefinition of the problem rather than anything else, which could have applied previously as well.
  • Performance: Unlike enterprise processors, Intel is pushing the frequency on the new HCC parts for consumers. This translates into a slightly lower base frequency but a much higher turbo frequency, along with support for Turbo Max. In essence, software that requires responsiveness can still take advantage of the high frequency turbo modes, as long as the software is running solo. The disadvantage is going to be in power consumption, which is a topic later in the review.
  • Platform Integration: Intel ‘solved’ this by creating one consumer platform suitable for nine processors with three different designs (Kaby Lake-X, Skylake-X LCC and Skylake-X HCC). Both the Kaby Lake-X and Skylake-X parts have different power delivery methods, support different numbers of memory channels, and different numbers of PCIe lanes / IO. When this was first announced, there was substantial commentary that this was making the platform overly complex, and would lead to confusion (it lead to at least one broken processor in our testing).

Each of these areas has either been marked as solved, or redefined out of being issue (even if a user agrees with the redefinition or not). 

New Features in Skylake-X: Cache, Mesh, and AVX-512 Opinion: Why Counting ‘Platform’ PCIe Lanes (and using it in Marketing) Is Absurd


View All Comments

  • ddriver - Monday, September 25, 2017 - link

    You are living in a world of mainstream TV functional BS.

    Quantum computing will never replace computers as we know and use them. QC is very good at a very few tasks, which classical computers are notoriously bad at. The same goes vice versa - QC suck for regular computing tasks.

    Which is OK, because we already have enough single thread performance. And all the truly demanding tasks that require more performance due to their time staking nature scale very well, often perfectly, with the addition of cores, or even nodes in a cluster mode.

    There might be some wiggle room in terms of process and material, but I am not overly optimistic seeing how we are already hitting the limits on silicon and there is no actual progress made on superior alternatives. Are they like gonna wait until they hit the wall to make something happen?

    At any rate, in 30 years, we'd be far more concerned with surviving war, drought and starvation than with computing. A problem that "solves itself" ;)
  • SharpEars - Monday, September 25, 2017 - link

    You are absolutely correct regarding quantum computing and it is photonic computing that we should be looking towards. Reply
  • Notmyusualid - Monday, September 25, 2017 - link

    @ SharpEars

    Yes, as alluded to by IEEE. But I've not looked at it in a couple of years or so, and I think they were still struggling with an optical DRAM of sorts.
  • Gothmoth - Monday, September 25, 2017 - link

    and what have they done for the past 6 years?

    i am glad that i get more cores instead of 5-10% performance per generation.
  • Krysto - Monday, September 25, 2017 - link

    The would if they could. Improvements in IPC have been negligible since Ivy Bridge. Reply
  • kuruk - Monday, September 25, 2017 - link

    Can you add Monero(Cryptonight) performance? Since Cryptonight requires at least 2MB of L3 cache per core for best performance, it would be nice to see how these compare to Threadripper. Reply
  • evilpaul666 - Monday, September 25, 2017 - link

    I'd really like it if Enthusiast ECC RAM was a thing.

    I used to always run ECC on Athlons back in the Pentium III/4 days.Now with 32-128x more memory that's running 30x faster it doesn't seem like it would be a bad thing to have...
  • someonesomewherelse - Saturday, October 14, 2017 - link

    It is. Buy AMD. Reply
  • IGTrading - Monday, September 25, 2017 - link

    I think we're being to kind on Intel.

    Despite the article clearly mentioning it in a proper and professional way, the calm tone of the conclusion seem to legitimize and make it acceptable that Intel basically deceives its customers and ships a CPU that consumes almost 16% more power than its stated TDP.


    I'm not "shouting" this :) , but I'm trying to underline this fact by putting it in caps.

    People could burn their systems if they design workstations and use cooling solutions for 165W TDP.

    If AMD would have done anything remotely similar, we would have seen titles like "AMD's CPU can fry eggs / system killer / motherboard breaker" and so on ...

    On the other hand, when Intel does this, it is silently, calmly and professionally deemed acceptable.

    It is my view that such a thing is not acceptable and these products should be banned from the market UNTIL Intel corrects its documentation or the power consumption.

    The i7960X fits perfectly in its TDP of 165W, how come i7980X is allowed to run wild and consume 16% more ?!

    This is similar with the way people accepted every crapping design and driver fail from nVIDIA, even DEAD GPUs while complaining about AMD's "bad drivers" that never destroyed a video card like nVIDIA did. See link : https://www.youtube.com/watch?v=dE-YM_3YBm0

    This is not cutting Intel "some slack" this is accepting shit, lies and mockery and paing 2000 USD for it.

    For 2000$ I expect the CPU to run like a Bentley for life, not like modded Mustang which will blow up if you expect it to work as reliably as a stock model.
  • whatevs - Monday, September 25, 2017 - link

    What a load of ignorance. Intel tdp is *average* power at *base* clocks, uses more power at all core turbo clocks here. Disable turbo if that's too much power for you. Reply

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