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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Wrs - Saturday, November 6, 2021 - link
Nah, they just weren't that competitive. Athlon64 was decent (lot of credit to Jim Keller) but didn't let AMD take massive advantage of Intel's weakness during the Pentium 4 era because AMD fabs were capacity limited. Once Conroe came out mid 2006 the margins dried up rapidly and AMD had no good response and suffered a talent exodus. It's true Intel made it worse with exclusivity bonuses, but I think AMD's spiral toward selling their fabs would have happened anyway. No way they were going to catch up with tick-tock and Intel's wallet.GeoffreyA - Monday, November 8, 2021 - link
I've always felt the K10 wasn't aggressive enough, owing to AMD not having factored Conroe into their equations when K10 was designed. Then, like startled folk, they tried to take back the lead by a drastic departure in the form of Bulldozer; and that, as we know, sank them into the ditch. Nonetheless, I'm glad they went through the pain of Bulldozer: Zen wouldn't have been as good otherwise.mode_13h - Tuesday, November 9, 2021 - link
> FX series was as bad as it was for a couple of reasonsI thought I also heard they switched from full-custom layout to ASIC flow (maybe for the sake of APUs?). If so, that definitely left some performance on the table.
bunnyfubbles - Thursday, November 4, 2021 - link
3D v-cache will be out before Zen 4 and should help close the gap if not regain the overall lead on the high end. The problem for AMD is the competition below the i9 vs R9 realm, where the E cores really pull more than their weight and help the i9 compete with the R9s in multi, but for the i5s and i7s vs their R5 and R7 counterparts, its even-Steven with performance cores, then you have the E cores as the trump card.MDD1963 - Thursday, November 4, 2021 - link
If AMD gains an averge of ~10% in gaming FPS with the 3D cache onslaught, that should put them right back near the top...certainly much closer to the 12900K....geoxile - Thursday, November 4, 2021 - link
15% on average. 25% at the highest. Intel really should have offered a 16 P-core die for desktop smdh, classic intel blunderSpunjji - Friday, November 5, 2021 - link
That would be a hell of a large die and necessitate a total redesign of the on-chip fabric. I don't think it would really make any sense at all.RSAUser - Monday, November 8, 2021 - link
12900K is already huge, each performance core is the size of about 4 E cores, going 16C P-Core would probably mean a 70% die size increase, and then you run into core to core communication issues, AMD got around it with infinity fabric but that's why you have the higher latency access between cores in different core complexes and Intel gives a more consistent access time on higher end products. Intel's current cores are mosly ringbus, so travel from one core to the next, getting to 16 doesn't scale well, they used a mesh topology in some Skylake CPU's, that latency was too high and hampered performance badly, you'd run into that same issue with 16C.That's without checking into yield, getting 16C on one wafer that are all perfectly clocking high is going to be a very, very rare chip; AMD gets around it using the core complexes (CX) of 4 cores each, together into a CCD (core chiplet die) and then in Zen 3 (5000 series) is supposedly 8C CCX, which makes rare chips 8C if full ccx works well, else 6C if 2 can't make it turns into a 5600X.
StevoLincolnite - Friday, November 5, 2021 - link
AMD has an answer before Zen 4.And that is Zen 3 with V-Cache.
Spunjji - Friday, November 5, 2021 - link
"This is their Zen 1 moment"Indeed!
"at a lower price"
Not really, if you take platform into account (and you have to!)
"Zen 4 isnt even competing with Alder Lake, Raptor Lake is rumored to be out before Zen 4"
Potentially, but Zen 4 is a bigger jump from Zen 3 than Raptor is predicted to be from Alder. Raptor will have more E cores but it's on the same process, so it's likely to offer better perf/watt in multithreading but unlikely to increase overall performance substantially (unless they allow maximum power draw to increase).
"AMD has really screwed up with their launch cycle"
Not really? They're still competitive in both price/performance (accounting for platform cost) and perf/watt. Zen 3D should shore up that position well enough.
"Intel is truly back"
Yup!