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
@Netmsm I'll leave that to the market as I don't foresee using any of the 3 that soon lol. It would stand to reason that if one product is both cheaper and better, it would keep gaining share at the expense of the other. If that doesn't happen I would question the premise of cheaper + better. And seeing as it's a major market for Intel, I have little doubt they'll adjust prices if they do find themselves selling an inferior product.Netmsm - Sunday, November 7, 2021 - link
That's right. We always check performance per watt and per dollar. A product should be reasonable with respect to its price and power consumption, this is a must.12900k can consume up to 241 which is very closer to Threadripper not Ryzen 5900's TDP and yet competing with chips having 125 TDP! What a parody this is!
I can't disregard and throw away efficiency factor, that's all.
Spunjji - Friday, November 5, 2021 - link
Seeing this has made me very interested to see the value proposition Alder Lake will be offering in gaming notebooks. I was vaguely planning to switch up to a Zen 3+ offering for my next system, but this might be enough to make me reconsider.EnglishMike - Thursday, November 4, 2021 - link
<blockquote>re: Enterprise: Considering power consumption, it's like a Pyrrhic victory for Intel.</blockquote>Why? This is not an enterprise solution -- that's the upcoming Sapphire Rapids Xeon processors, a completely different CPU platform.
Sure, if all you're doing is pegging desktop CPUs at 100% for video processing or a similar workload, then Alder Lake isn't for you, but the gaming benchmarks clearly show that when it comes to more typical desktop workloads, the i9 12900k is inline with the top of the line AMD processors in terms of power consumption.
Netmsm - Thursday, November 4, 2021 - link
and who in his right mind would believe that upcoming Xeon processors can bring revolutionary breakthrough in power consumption?!EnglishMike - Friday, November 5, 2021 - link
And that, my friend, is a great example of moving the goalposts.We'll have to see what Intel offers re: Xeon's but one thing is for sure, they're going to offer a completely different power profile to their flagship desktop CPUs, because that's the nature of the datacenter business.
Netmsm - Saturday, November 6, 2021 - link
Of course the nature of enterprise won't accept this power consumption. In PC world customers may not care how ineffective a processor is. Intel will reduce the power consumption but the matter is how its processor will accomplish the job! We see an unacceptable performance to watt in Intel's new architecture that needs something like a miracle for Xeon's to become competitive with Epyc's.Wrs - Saturday, November 6, 2021 - link
No miracle is needed... just go down the frequency-voltage curve. Existing Ice Lake Xeons already do that. What's new about Sapphire Rapids is not so much the process tech (it's still 10nm) but the much larger silicon area enabled per package due to the EMIB packaging. That's their plan to be competitive with Epyc and its multichip modules.Netmsm - Sunday, November 7, 2021 - link
And what will happen to performance as frequency-voltage curve goes down?Just look at facts! With about 100w more power consumption Intel's new architecture gets itself in front of Zen 3 by a slight margin in some cases that lucidly tells us it can never reduce power consumption and yet beat Epyc in performance.
Wrs - Sunday, November 7, 2021 - link
@Netmsm I'm looking at facts. The process nodes are very similar. One side has both a bigger/wider core (Golden Cove) and a really small core (Gracemont). The other side just has the intermediate size core (Zen 3). As a result, on some benchmarks one side wins by a fair bit, and on other benchmarks, the other side takes the cake. Many benches are a tossup.In this case the side that theoretically wins on efficiency at iso-throughput (MC performance) is the side that devotes more total silicon to the cores & cache. When comparing a 12900k to a 5950x, the latter has slightly more area across the CCDs, about 140 mm2 versus around 120 mm2. The side that's more efficient at iso-latency (ST/lightly threaded) is the one that devotes more silicon to their largest/preferred cores, which obviously here is ADL. In practice companies don't release their designs at iso-performance, and for throughput benchmarks one may encounter memory and other platform bottlenecks. But Intel seems to have aggressively clocked Golden Cove such that it's impossible for AMD to reach iso-latency with Zen 3 no matter the power input (i.e., you'd have to downclock the ADL). That has significant end-user implications as not everything can be split into more threads.
The Epyc Rome SKUs are already downclocked relative to Vermeer, like most server/workstation CPUs. Epyc Rome tops out at 64 Zen3 cores across 8 chiplets. Sapphire Rapids, which isn't out yet, has engineering samples topping out at 80 Golden Cove cores across 4 ~400mm2 chiplets. Given what we know about relative core sizes, which side is devoting more silicon to cores? There's your answer to performance at iso-efficiency. That's not to say it's fair to compare a product a year out vs. one you can obtain now, but also I don't see a Zen4 or N5 AMD server CPU within the next year.