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.
Facebook
Twitter
RSS
474 Comments
View All Comments
Kvaern1 - Sunday, November 7, 2021 - link
Because there are no games which are 'incompatible'' with ADL.eastcoast_pete - Sunday, November 7, 2021 - link
While AL is an interesting CPU (regardless of what one's preference is), I still think the star of AL is the Gracemont core (E cores), and did some very simple-minded, back of a napkin calculations. The top AL has 8 (P cores with multithreading) = 16 + 8 E core threads (no multithreading here) for a total of 24 threads. According to first die shots, one P core requires the same die area as 4 E cores. That leaves me wanting an all-E core CPU with the same die size as the i9 AL, because that could fit 8x4= 32 plus the existing 8 Gracemonts, for a total of 40. And, the old problem of "Atoms can't do AVX and AVX2" is solved - because now they can! Yes, single thread performance would be significantly lower, but any workload that can take advantage of many threads should be at least as fast as on the i9. Anyone here knows if Intel is considering that? It wouldn't be the choice for gaming, but for productivity, it might give both the i9 and, possibly, the 5950x a run for the money.mode_13h - Monday, November 8, 2021 - link
They currently make Atom-branded embedded server CPUs with up to 24 cores. This one launched last year, using Tremont cores:https://ark.intel.com/content/www/us/en/ark/produc...
I think you can expect to see a Gracemont-based refresh, possibly with some new product lines expanding into non-embedded markets.
eastcoast_pete - Monday, November 8, 2021 - link
Yes, those Tremont-based CPUs are intended/sold for 5G cell stations; I hope that Intel doesn't just refresh those with Gracemont, but makes a 32-40 Gracemont core CPU available for workstations and servers. The one thing that might prevent that is fear (Intel's) of cannibalizing their Sapphire Rapid sales. However, if I would be in their shoes, I'd worry more about upcoming AMD and multi-core ARM server chips, and sell all the CPUs they can.mode_13h - Tuesday, November 9, 2021 - link
Well, it's a start that Intel is already using these cores in *some* kind of server CPU, no? That suggests they already should have some server-grade RAS features built-in. So, it should be a fairly small step to use them in a high core count CPU to counter the Gravitons and Altras. I think they will, since it should be more competitive in terms of perf/W.As for workstations, I think you'll need to find a workstation board with a server CPU socket. I doubt they'll be pushing massive E-core -only CPUs specifically for workstations, since workstation users also tend to care about single-thread performance.
anemusek - Sunday, November 7, 2021 - link
Sorry but performance it isn't all +- a few percent in the real world will not restore confidence. Critical flaws, disabling functionality (dx12 in hanswell for example), instabbility instruction features etc.I cannot afford to trust such a company
Dolda2000 - Sunday, November 7, 2021 - link
I just wanted to add a big Kudos for this article. AnandTech's coverage of the 12900K was by a wide margin the best of any I read or watched, with regards to coverage of the various variables involved, and with the breadth and depth of testing. Thanks for keeping it up!chantzeleong - Monday, November 8, 2021 - link
I run Power bi and tensorflow with large dataset. Which Intel CPU do you recommend and why?mode_13h - Tuesday, November 9, 2021 - link
I don't know about "Power bi", but Tensorflow should run best on GPUs. Which CPU to get then depends on how many GPUs you're going to use. If >= 3, then Threadripper. Otherwise, go for Alder Lake or Ryzen 5000 series.You'll probably find the best advice among user communities for those specific apps.
velanapontinha - Monday, November 8, 2021 - link
We've seen this before. It is time to short AMD, unfortunately.