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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adamxpeter - Friday, November 5, 2021 - link
Very poetic post.bananaforscale - Friday, November 5, 2021 - link
Seems we're actually getting a Zen 3 refresh early next year. Alder Lake's lead also decreases with DDR4, gaming above 1080p (so basically anyone who would buy a 12900K for a gaming rig), it uses more power and with DDR5 you pay extra for memory.Yeah, Alder Lake has some advantages. Not sure I'd call it a better overall package at the moment.
madseven7 - Saturday, November 6, 2021 - link
Intel is back at the cost of power. AMD at that power will destroy Intel. Intel basically said screw TDP.Qasar - Saturday, November 6, 2021 - link
intel has been saying that for 2-3 years now, its the only way their chips can be competitive with zen 2 and 3Maverick009 - Sunday, November 7, 2021 - link
They really haven't screwed up as you would like to think. I do believe AMD was thrown off some by the unexpected performance in Hybrid design. They still do trade blows between some games, multi-threaded software, and on applications that are just not optimized for Alder Lake.What I have noticed though in the days since Alder Lake's NDA went up and reviews came out, is leaks to AMD's next gen Zen CPUs have begun to trinkle out a little more than usual. Yes we have Zen 4 on the way, which will pave the way for DDR5 and PCIe Gen5 along with an uplift in IPC. However the real secret sauce may be in Zen 4D as the platform to build a heavily multi-threaded core package along with SMT enabled, and then Zen 5. The big picture, is AMD's version of a Hybrid CPU may include a combination of Zen 4D big cores and Zen 5 Bigger cores. The Zen 4D are said to possibly carry as many as 16 cores per chiplet, too, so it would speak to a possible heavily multi-threaded efficient CPU, while sacrificing a little bit of single threaded performance to achieve it. The timeframe would also put the new Hybrid CPU on a collision course to battle Raptor Lake.
For once the CPU market has gotten interesting again, and the consumer ultimately wins here.
NikosD - Monday, November 8, 2021 - link
@reviewersSince AVX-512 is working on ADL, it would be useful to test the AVX-512 vs AVX2 power consumption of ADL by running POVRAY using P-cores only and compare that maximum AVX2 power consumption to AVX-512 max power consumption using 3DPM.
Because max 272W power consumption of POVRAY as reported, includes 48W from E-cores too.
mode_13h - Tuesday, November 9, 2021 - link
> it would be useful to test the AVX-512 vs AVX2 power consumption of ADL by running POVRAYI'm not sure of POV-Ray is the best way to stress AVX-512.
NikosD - Wednesday, November 10, 2021 - link
They have already tested max power consumption of AVX-512 using 3DPM.I just asked to test POVRAY using P-cores only, for max power consumption of AVX2 in order to compare with 3DPM.
usernametaken76 - Monday, November 8, 2021 - link
lolxhris4747 - Tuesday, November 9, 2021 - link
They did not take the performance crown gaming is almost tied overall mt is a mixed bag hopefully they use pbo which gives about 27k-30k on c23