The Intel 12th Gen Core i9-12900K Review: Hybrid Performance Brings Hybrid Complexity
by Dr. Ian Cutress & Andrei Frumusanu on November 4, 2021 9:00 AM ESTCPU 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.
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.
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.
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.
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MDD1963 - Thursday, November 4, 2021 - link
Not sure what statement was actually intended there....jerrylzy - Friday, November 5, 2021 - link
Even with DDR5 and PCIe 5.0 Intel is only barely competitive with AMD on the high end, and that's pretty sad. Only 12600K is competitive.Spunjji - Friday, November 5, 2021 - link
PCIe 5.0 is currently useless to consumers and likely to be so for the duration of ADL's life. DDR5 is currently far more expensive and doesn't provide a compelling performance benefit for most users.So, yeah - just as Comet Lake was a reasonable alternative to Zen 2 and 3 for many users despite being stuck on PCIe 3.0, so ADL doesn't really make a compelling argument for itself just by having PCIe 5.0.
NikosD - Friday, November 5, 2021 - link
@reviewersAny sign of AMX silicon inside P-cores ?
As another Intel's surprise like AVX-512, I mean.
cc2onouui - Friday, November 5, 2021 - link
Good performance with DDR5 but this review is less than complete (after you started "intel vs AMD ddr4 was not used for the tests) that's odd because DRAM price and MB makes the pick..it's sad that an important review with too much effort (now more than 17000 words)looks only on the shallow.. is windows 10 used for gaming tests or 11 and why ddr4 is out so the not good enough 2080ti5j3rul3 - Thursday, November 4, 2021 - link
Is there any advanced analysis between TSMC N7 and Intel 7?grahaman27 - Thursday, November 4, 2021 - link
Both are marketing terms that mean nothing. There.Wrs - Thursday, November 4, 2021 - link
But they happen to be surprisingly close. Can't go wrong with one over the other.Spunjji - Friday, November 5, 2021 - link
They are both marketing terms, yes, but they both refer to actual processes that can be compared.Fataliity - Thursday, November 4, 2021 - link
Der8auer had a video at... Kleindeck i think? Where they analyzed the transistors of Intel 10nm vs AMD 7nm processor. Essentially they are almost equal.