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 Benchmark Performance: DDR5 vs DDR4
Traditionally we test our memory settings at JEDEC specifications. JEDEC is the standards body that determines the requirements for each memory standard. In this case, the Core i9 supports the following aligning with those standards:
- DDR4-3200 CL22
- DDR5-4800B CL40*
There's an * next to the DDR5 for a couple of reasons. First, when asked, Intel stated that 4800A (CL34) was the official support, however since the technical documents have now been released, we've discovered that it is 4800B (CL40). Secondly, 4800B CL40 technically only applies to 1 module per 64-bit channel on the motherboard, and only when the motherboard has two 64-bit slots to begin with. We covered Intel's memory support variants in a previous article, and in this instance, we're using DDR5-4800B memory in our testing.
As explained in our SPEC section, DDR5 memory not only brings bandwidth improvements but also the increased number of channels (4x32-bit vs 2x64-bit) means that the memory can be better utilized as threads pile on the memory requests. So while we don't see much improvement in single threaded workloads, there are a number of multi-threaded workloads that would love the increased performance.
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blanarahul - Thursday, November 4, 2021 - link
"Using all the eight E-cores, at 3.9 GHz, brings the package power up to 48 W total."This sounds amazing for inexpensive (i3 class) laptop processors since Gracemont sips power and doesn't take much die space.
Great_Scott - Thursday, November 4, 2021 - link
I'd actually prefer a all-Gracemont CPU for Laptops. Seems like it would be better for intentionally maximizing battery life. Skylake+ level performance is perfect for most use cases.TheinsanegamerN - Thursday, November 4, 2021 - link
Indeed, they have it backwards for laptops, it should be 2-6 gracemont cores then 1-2 power cores for a CPU, not the other way around.karmapop - Thursday, November 4, 2021 - link
I'm guessing you missed the articles describing the two separate mobile dies for Alder Lake? We've got Alder Lake-P (6P + 8E) for performance mobile designs, and Alder Lake-M (2P + 8E) for the ultra mobile low power SKUs.at_clucks - Saturday, November 6, 2021 - link
I'm very happy with exactly-Skylake-level performance in my desktop :). I'd more than gladly take the same performance and cut the power in half. I'm sure there's quite a big market for that kind of performance in a lower powered package regardless of form factor (mobile, desktop).Meteor2 - Tuesday, November 9, 2021 - link
There really is. I may well pick up a 2P+8E ADL laptop, but a desktop box would suit me bettermode_13h - Wednesday, November 10, 2021 - link
Keep an eye on ASRock. They sell mini-ITX motherboards with that class of SoC.https://www.asrock.com/mb/index.us.asp#Intel%20CPU
Spunjji - Friday, November 5, 2021 - link
That's actually not great in power terms compared to what AMD can do with 8 Zen 3 cores on TSMC N7 - but yeah, in the context of die area, something built around (say) 2 P cores and 4 E cores can probably put in a very good showing for inexpensive devices.Netmsm - Thursday, November 4, 2021 - link
Becomes competitive to previous AMD's.EnglishMike - Thursday, November 4, 2021 - link
Previous AMDs support DDR5 and PCR 5.0?Huh. That one slipped by me...