CPU Tests: SPEC MT Performance - DDR5 Advantage

Multi-threaded performance is where things become very interesting for Alder Lake, where the chip can now combine its 8 P-cores with its 8 E-cores. As we saw, the 8 E-cores are nothing to sneeze about, but another larger consideration for MT performance is DDR5. While in the ST results we didn’t see much change in the performance of the cores, in MT scenarios when all cores are hammering the memory, having double the memory channels as well as +50% more bandwidth is going to be extremely beneficial for Alder Lake.

SPECint2017 Rate-N Estimated Scores

As we noted, the DDR5 vs DDR4 results showcase a very large performance gap between the two memory technologies in MT scenarios. Running a total of 24 threads, 16 for the SMT-enabled P-cores, and 8 for the E-cores, Alder Lake is able to take the performance crown in quite a lot of the workloads. There are still cases where AMD’s 16-core setup with larger cores are able to perform better, undoubtedly also partly attributed to 64MB of on-chip cache.

Compared to the 11900K, the new 12900K showcases giant leaps, especially when paired with DDR5.

SPECfp2017 Rate-N Estimated Scores

In the FP suite, the DDR5 advantage in some workloads is even larger, as the results scale beyond that of the pure theoretical +50% bandwidth improvement. What’s important for performance is not just the theoretical bandwidth, but the actual utilised bandwidth, and again, the doubled up memory channels of DDR5 here are seemingly contributing to extremely large increases, if the workload can take advantage of it.

SPEC2017 Rate-N Estimated Total

In the aggregate results, there’s very clearly two conclusions, depending on whether you use the chip with DDR5 or DDR4.

With DDR4, Alder Lake and the 12900K in particular, is able to showcase very good and solid increases in performance, thanks to the IPC gains on the Golden Cove core, but most importantly, also thanks to the extra 8 Gracemont cores, which do carry their own weight. The 12900K falls behind AMD’s 5900X with DDR4, which is fair given the pricing of the chips here are generally in line with teach other.

With DDR5, the 12900K is able to fully stretch its multi-threaded performance legs. In less memory dependent workloads, the chip battles it out with AMD’s 16-core 5950X, winning some workloads, losing some others. In more memory dependent workloads, the DDR5 advantage is extremely clear, and the 12900K is able to blow past any competition, even slightly edging out the latest Apple M1 Max, released a few weeks ago, and notable for its memory bandwidth.

CPU Tests: SPEC ST Performance on P-Cores & E-Cores CPU Tests: SPEC MT Performance - P and E-Core Scaling
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  • 5j3rul3 - Thursday, November 4, 2021 - link

    Great step for intel
  • Bobbyjones - Thursday, November 4, 2021 - link

    Indeed. Biggest improvements since sandybridge. If you look at the timeline, this wouldve been the first CPU designed since they saw Zen 1. This is their Zen 1 moment and they already took the performance crown back basically across the board and at a lower price. AMD is now on the back foot, and it will be another whole year before Zen 4, and the thing is, Zen 4 isnt even competing with Alder Lake, Raptor Lake is rumored to be out before Zen 4. AMD has really screwed up with their launch cycle and given Intel so much room that they not only caught back up but beat them. Intel is truly back.
  • Netmsm - Thursday, November 4, 2021 - link

    For now Threadripper has the performance crown.
    With this performance per watt, Intel can just win the market for PCs.
    Enterprise will never accept this performance per watt! So, AMD wins the high profitable enterprise market.
    12900k guzzles power up to 241! whereas 5950x consumes half!

    Considering power consumption, it's like a Pyrrhic victory for Intel.
  • fazalmajid - Thursday, November 4, 2021 - link

    The HEDT market in Enterprise is workstations, which run certified apps like AutoCAD and has a lot of inertia. The first real Zen workstation is the Lenovo P620 and it only recently came out, so AMD hasn't conquered that market yet. Most actual Enterprise desktops are compact models that typically run on laptop CPUs.
  • DominionSeraph - Friday, November 5, 2021 - link

    And Intel has AMD beat for miles in system validation.
    My 3950X on a x570 Phantom Gaming X has major issues with disk access across one NVMe, one SATA SSD, and two HDDs. Some things will start up fine, but some things will just HANG. Deus Ex loading screens take like 10 seconds. I just tried to play a video off my NVMe and it took ~15 seconds for it to launch MPC-HC. (further launches are fine.) MeGUI takes 15 seconds to launch.
    This thing is just frustratingly slow in general desktop tasks compared to my old i7 4790.
    Does it beat the pants off the 4790 in heavily multithreaded crunching? Yes. But iAMD does not put out a quality product.
  • Gothmoth - Friday, November 5, 2021 - link

    anecdotal evidence? ....YOU have issues with your system.
    well we have 16 core ryzen and threadripper 32 & 64 core systems at work and we can´t complain.
    it´s not as if intel is issue free (and i am not taking about security flaws).

    when you have such grave issues.. YOUR system has issues.
    probably a bad setup. i did not hear that starting MPC needs 15 seconds when i read abourt AMD systems.
  • dotjaz - Sunday, November 7, 2021 - link

    What about USB issues that are publicly acknowledged AND multiple BIOSes claim to have fixed it, yet here we are.
  • Netmsm - Friday, November 5, 2021 - link

    It is your problem not AMD nor Intel!
    This is why we always refer to QVL of MB before buying RAM, SSD, etc. to avoid such problems. It is not AMD prerogative rather it is for all platforms.
    For now you may better update MB bios as soon as it is released. To solve the problem completely you need to reassemble it according to the MB's QVL.
  • DominionSeraph - Friday, November 5, 2021 - link

    It is an AMD issue. I've put together hundreds of Intel systems and none of them have any issues.
  • Netmsm - Friday, November 5, 2021 - link

    When you face abnormality just put your cards on the table and ask a pro.

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