The Intel 12th Gen Core i9-12900K Review: Hybrid Performance Brings Hybrid Complexityby Dr. Ian Cutress & Andrei Frumusanu on November 4, 2021 9:00 AM EST
Today marks the official retail availability of Intel’s 12th Generation Core processors, starting with the overclockable versions this side of the New Year, and the rest in 2022. These new processors are the first widescale launch of a hybrid processor design for mainstream Windows-based desktops using the underlying x86 architecture: Intel has created two types of core, a performance core and an efficiency core, to work together and provide the best of performance and low power in a singular package. This hybrid design and new platform however has a number of rocks in the river to navigate: adapting Windows 10, Windows 11, and all sorts of software to work properly, but also introduction of DDR5 at a time when DDR5 is still not widely available. There are so many potential pitfalls for this product, and we’re testing the flagship Core i9-12900K in a few key areas to see how it tackles them.
Let’s Talk Processors
Since August, Intel has been talking about the design of its 12th Generation Core processor family, also known as Alder Lake. We’ve already detailed over 16000 words on the topic, covering the fundamentals of each new core, how Intel has worked with Microsoft to improve Windows performance with the new design, as features like DDR5, chipsets, and overclocking. We’ll briefly cover the highlights here, but these two articles are worth the read for those that want to know.
- Intel Architecture Day 2021: Alder Lake, Golden Cove, and Gracemont Detailed
- Intel 12th Gen Core Alder Lake for Desktops: CPUs, Chipsets, Power, DDR5, OCh
At the heart of Intel’s processors is a hybrid, or heterogeneous, core design. The desktop processor silicon will have eight performance cores (P-cores) and eight efficiency cores (E-cores), the latter in two groups of four. Each of the cores is designed differently to optimize for their targets, but supports the same software. The goal is that software that is not urgent runs on efficiency cores, but time-sensitive software runs on performance cores, and that has required a new management control between the processor and Windows has been developed to enable Alder Lake to work at its best. That control is fully enabled in Windows 11, and Windows 10 can get most of the way there but doesn’t have all the bells and whistles for finer details – Linux support is in development.
The use of this hybrid design makes some traditional performance measurements difficult to compare. Intel states that individually the performance cores are +19% over 11th Generation, and the efficiency cores are around 10th Generation performance levels at much lower power. At peak performance Intel has showcased in slides that four E-cores will outperform two 6th Generation cores in both performance and power, with the E-core being optimized also for performance per physical unit of silicon. Alternatively, Intel can use all P-cores and all E-cores on a singular task, up to 241W for the Core i9 processor.
On top of all this, Intel is bringing new technology into the mix with 12th Gen Core. These processors will have PCIe 5.0 support, but also DDR5-4800 and DDR4-3200 support on the memory. This means that Alder Lake motherboards, using the new LGA1700 socket and Z690 chipsets, will be either DDR4 or DDR5 compatible. No motherboard will have slots for both (they’re not interchangeable), but as we are quite early in the DDR5 lifecycle, getting a DDR4 motherboard might be the only way for users to get hold of an Alder Lake system using their current memory. We test both DDR4 and DDR5 later on in the review to see if there is a performance difference.
A small word on power (see this article for more info) – rather than giving a simple ‘TDP’ value as in previous generations, which only specified the power at a base frequency, Intel is expanding to providing both a Base power and a Turbo power this time around. On top of that, Intel is also making these processors have ‘infinite Turbo time’, meaning that with the right cooling, users should expect these processors to run up to the Turbo power indefinitely during heavy workloads. Intel giving both numbers is a welcome change, although some users have criticized the decreasing turbo power for Core i7 and Core i5.
As we reported last week, here are the processors shipping today:
|Intel 12th Gen Core, Alder Lake|
Processors that have a K are overclockable, and those with an F do not have integrated graphics. The graphics on each of the non-F chips are Xe-LP graphics, the same as the previous generation.
At the top of the stack is the Core i9-12900K, with eight P-cores and eight E-cores, running at a maximum 241 W. Moving down to i7 gives eight P-cores and four E-cores at 190 W, and the Core i5 gives six P-cores and four E-cores at 150 W. We understand that future processors may have six P-core and zero E-core designs.
|Compare at $550+|
|* AMD Quotes RRP, Intel quotes 'tray' as 1000-unit sales. Retail is ~$650|
The Core i9-12900K, the focus of this review today, is listed at a tray price of $589. Intel always lists tray pricing, which means ‘price if you buy 1000 units as an OEM’. The retail packaging is often another +5-10% or so, which means actual retail pricing will be nearer $650, plus tax. At that pricing it really sits between two competitive processors: the 16-core Ryzen 9 5950X ($749) and the 12-core Ryzen 9 5900X ($549).
Let’s Talk Operating Systems
Suffice to say, from the perspective of a hardware reviewer, this launch is a difficult one to cover. Normally with a new processor we would run A vs B, and that’s most of the data we need aside from some specific edge cases. For this launch, there are other factors to consider:
- P-core vs E-core
- DDR5 vs DDR4
- Windows 11 vs Windows 10
Every new degree of freedom to test is arguably a doubling of testing, so in this case 23 means 8x more testing than a normal review. Fun times. But the point to drill down to here is the last one.
Windows 11 is really new. So new in fact that performance issues on various platforms are still being fixed: recently a patch was put out to correct an issue with AMD L3 cache sizes, for example. Even when Intel presented data against AMD last week, it had to admit that they didn’t have the patch yet. Other reviewers have showcased a number of performance consistency issues with the OS when simply changing CPUs in the same system. The interplay of a new operating system that may improve performance, combined with a new heterogeneous core design, combined with new memory, and limited testing time (guess who’s CPUs were held in customs for a week), means that for the next few weeks, or months, we’re going to be seeing new performance numbers and comparisons crop up.
From Intel’s perspective, Windows 11 brings the full use of its Thread Director technology online. Normally the easiest way to run software on a CPU is to assume all the cores are the same - the advent of hyperthreading, favoured core, and other similar features meant that add-ins were applied to the operating system to help it work as intended at the hardware level. Hybrid designs add much more complexity, and so Intel built a new technology called Thread Director to handle it. At the base level, TD understands the CPU in terms of performance per core but also efficiency per core, and it can tell P-core from E-core from favoured P-core from a hyperthread. It gathers all this information, and tells the operating system what it knows – which threads need performance, what threads it thinks needs efficiency, and what are the best candidates to move up or down that stack. The operating system is still king, and can choose to ignore what TD suggests, but Windows 11 can take all that data and make decisions depending on what the user is currently focused on, the priority level of those tasks, and additional software hooks from developers regarding priority and latency.
The idea is that with Windows 11, it all works. With Windows 10, it almost all works. The main difference Intel told us is although Windows 10 can separate cores apart, and hyperthreads, it doesn’t really understand efficiency that well. So its decisions are made more in regards to performance requirements, rather than performance vs efficiency. At the end of the day, all this should mean to the user is that Windows 10 tries to minimizes the run-to-run variation, but Windows 11 does it better. Ultimate best-case performance shouldn’t change in any serious way: a single thread on a P-core, or across several P-cores for example, should perform the same.
Let’s Talk Testing
This review is going to focus on these specific comparisons:
- Core i9-12900K on DDR5 vs the Competition
- Core i9-12900K on DDR5 vs Core i9-12900K on DDR4
- Power and Performance of the P-Core vs E-Core
- Core i9-12900K Windows 11 vs Windows 10
Normally when a new version of Windows is launched, I stay as far away from it as possible. On a personal level, I enjoy consistency and stability in my workflow, but also when it comes to reviewing hardware – being able to be confident in having a consistent platform is the only true way to draw meaningful conclusions over a sustained period. Nonetheless, when a new operating system is launched, there is always the call to bulk wholesale move testing to a new platform. Windows 11 is Windows 10 with a new dress and some details moved around and improved, so it should be easier than most, however I’m still going to wait until the bulk of those initial early adopter issues, especially those that might affect performance are solved, before performing a flat refresh of our testing ecosystem. Expect that to come in Q2 next year, where we will also be updating to NVMe testing, and soliciting updates for benchmarks and new tests to explore.
For our testing, we’re leveraging the following platforms:
|Alder Lake Test Systems|
8+8 Cores, 24 Threads
125W Base, 241W Turbo
|Motherboard||MSI Z690 Unify||MSI Z690 Carbon Wi-Fi|
|Corsair H150i Elite
|Storage||Crucial MX500 2TB|
|Power Supply||Corsair AX860i|
|GPUs||Sapphire RX460 2GB (Non-Gaming Tests)
NVIDIA RTX 2080 Ti (Gaming Tests), Driver 496.49
|Operating Systems||Windows 10 21H1
Windows 11 Up to Date
Ubuntu 21.10 (for SPEC Power)
All other chips for comparison were ran as tests listed in our benchmark database, Bench, on Windows 10.
Highlights of this review
- The new P-core is faster than a Zen 3 core, and uses 55-65 W in ST
- The new E-core is faster than Skylake, and uses 11-15 W in ST
- Maximum all-core power recorded was 272 W, but usually below 241 W (even in AVX-512)
- Despite Intel saying otherwise, Alder Lake does have AVX-512 support (if you want it)!
- Overall Performance of i9-12900K is well above i9-11900K
- Performance against AMD overall is a mixed bag: win on ST, MT varies
- Performance per Watt of the P-cores still lags Zen3
- There are some fundamental Windows 10 issues (that can be solved)
- Don’t trust thermal software just yet, it says 100C but it’s not
- Linux idle power is lower than Windows idle power
- DDR5 gains shine through in specific MT tests, otherwise neutral to DDR4
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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 - linkThat'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 - linkSeeing 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 - linkand who in his right mind would believe that upcoming Xeon processors can bring revolutionary breakthrough in power consumption?!
EnglishMike - Friday, November 5, 2021 - linkAnd 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 - linkOf 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 - linkNo 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 - linkAnd 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.