The Intel Comet Lake Core i9-10900K, i7-10700K, i5-10600K CPU Review: Skylake We Go Again
by Dr. Ian Cutress on May 20, 2020 9:00 AM EST- Posted in
- CPUs
- Intel
- Skylake
- 14nm
- Z490
- 10th Gen Core
- Comet Lake
Power
We kind of gave a sneak preview on the front page with our frequency graph, but the short answer as to whether these new Core i9 processors really need 250 W for 10 cores is yes. Intel sent us details on what it has determined should be the recommended settings for its K processor line:
- Core i9-10900K: TDP is 125 W, PL2 is 250 W, Tau is 56 seconds
- Core i7-10700K: TDP is 125 W, PL2 is 229 W, Tau is 56 seconds
- Core i5-10600K: TDP is 125 W, PL2 is 182 W, Tau is 56 seconds
For those not used to these terms, we have the TDP or Thermal Design Power, which is meant to be the long-term sustained power draw of the processor at which Intel guarantees the base frequency of the processor – so in this case, the Core i9-10900K guarantees that with a heavy, long-running workload it will max out at 125 W with a frequency of at least 3.7 GHz (the base frequency).
The PL2 is known as the turbo power limit, which means that while the processor is allowed to turbo, this is the upper power limit that the processor can reach. As mentioned on the first page of this review, the value for PL2 is only a suggested guide, and Intel lets motherboard vendors set this value to whatever they want based on how well the motherboard is designed. Sometimes in laptops we will see this value lower than what Intel recommends for thermal or battery reasons, however on consumer motherboards often this value is as high as it can possibly be.
The final term, Tau, is meant to be a time by which the turbo can happen. In reality the TDP value and the Tau value is multiplied together to give a value for a ‘bucket’ of energy that the processor can use to turbo with. The bucket is refilled at a continuous rate, but if there is excess energy then the processor can turbo – if the bucket is being emptied at the same rate as it is refilled, then the processor is down at the long-term TDP power limit. Again, this is a value that Intel recommends and does not fix for the vendors, and most consumer motherboards have Tau set to 999 seconds (or the equivalent of infinite time) so the processor can turbo as much as possible.
Note, when we asked Intel about why it doesn’t make these hard specifications and how we should test CPUs given that we’re somewhat enable to keep any motherboard consistent (it might change between BIOS revisions) for a pure CPU review, the response was to test a good board and a bad board. I think that on some level Intel’s engineers don’t realize how much Intel’s partners abuse the ability to set PL2 and Tau to whatever values they want.
All that aside, we did some extensive power testing on all three of our CPUs across a number of simulation and real-world benchmarks.
Core i9-10900K Power
Through our tests, we saw the Intel Core i9-10900K peak at 254 W during our AVX2-accelerated y-cruncher test. LINPACK and 3DPMavx did not push the processor as hard.
The more real-world tests, AI Benchmark and Photoscan, showed that in a variable operation workload mixing threads, we are more likely to see the 125-150 W range, with spikes up to 200W for specific operations.
For users interested in the voltage for our Core i9-10900K, we saw the processor peak at 1.34 volts, however even during an AVX2 workload it was nearer to 1.25 volts.
Intel Core i7-10700K
The Intel Core i7-10700K is rated by Intel to have a peak turbo power of 229 W, however our sample peaked at 207 W during y-Cruncher. LINPACK achieved similar results, whereas 3DPMavx was nearer 160 W.
Our AI Benchmark power wrapper failed for the 10700K due to a configuration issue, but the Photoscan ‘real world’ power test put the processor mostly in the 100-125 W range, peaking just below 150 W in a couple of places.
Intel Core i5-10600K
Intel’s Core i5-10600K has a recommended PL2 of 182 W, but we observed a peak of 125 W in y-Cruncher and 131 W in LINPACK.
We actually saw our AI Benchmark real-world test hit 130 W as well, while Photoscan was nearer the 60-80 W range for most of the test.
The full set of power graphs can be found here:
In terms of overall peak power consumption, our values look like this:
Note, 254 W is quite a lot, and we get 10 cores at 4.9 GHz out of it. By comparison, AMD's 3990X gives 64 cores at 3.2 GHz for 280 W, which goes to show the trade-offs between going wide and going deep. Which one would you rather have?
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catavalon21 - Wednesday, May 20, 2020 - link
The ability to edit (or ^Z) would be most welcome, trust me.eastcoast_pete - Wednesday, May 20, 2020 - link
Isn't that Skylake running a bit dry by now? But, seriously, Intel really risks losing a lot of market share in future years by selling these "classics" at high prices, and that is if one can get one in the first place.Curious: how many commercial customers buy Intel desktops just because they have iGPUs, but want more CPU oomph than the 3200G has? Is that why Intel still dominates the OEM desktop market?
AnarchoPrimitiv - Wednesday, May 20, 2020 - link
Intel dominates the OEM market through intimidation and threats of retribution... They were literally convicted of bribing OEMs to NOT use AMD CPUs all throughout the 2000s in several courts around the world. The trials uncovered emails between Intel executives that stated, and I quote, "Dell is the best friend money can buy".... The proof is in the fact that currently, the Ryzen 4000 mobile CPUs are the best mobile chips offered right now, but Dell only puts them in the low end laptops. Why? Because Intel is probably giving huge financial incentives to bar AMD from premium designs to perpetuate the myth that AMD isn't a premium brandRetycint - Wednesday, May 20, 2020 - link
Do keep in mind that these are baseless speculations, based on something that happened 2 decades ago. Both Intel and AMD have changed since then (new engineering team, new management etc) and there has been no evidence of Intel providing incentives to cripple AMD systems. Go take your conspiracy elsewhere.And before you inevitably accuse me of being an Intel shill, this isn't about Intel or AMD, it's about facts to support your claim, of which there have been none
Irata - Wednesday, May 20, 2020 - link
Baseless speculation? Financial horsepower, MDF and meet the comp funds are current and no secret.Why do you think there are no Ryzen 4000 laptops with GPU above a 2060?
Spunjji - Tuesday, May 26, 2020 - link
Not entirely baseless, as they made two distinct claims. I've been a party to how Intel's "Marketing Development Funds" work - and work it does, at all levels from OEM to reseller to retailer. These days they don't explicitly punish anyone for not buying AMD - they simply tie rebates that will improve the profit margins on a product to specific quantities of those products being sold. It's "nobody's fault" if those quantities happen to make the sale of an AMD product by a given retailer or reseller distinctly unlikely.As for incentivizing bad *builds* of AMD systems, though, I'm not so sure. Intel clearly do a lot of work building reference platforms, and the economics of doing integration testing for a new vendor is not trivial. Honestly though, it's hard to tell how we *would* know if this were going on, because it would absolutely be made to look innocent - just like last time.
brantron - Wednesday, May 20, 2020 - link
"literally convicted of bribing"1) No. That's not what "literally" means.
2) No. No one was even *charged* with a crime, much less convicted.
3) No. It wasn't about bribery.
The reason Athlon 64s weren't ubiquitous way back when is the same reason the 4000 APUs aren't today - there aren't enough to go around.
If your post were to be rephrased without hyperbole, baseless accusations, and whataboutism unrelated to the topic of this article, it would read something like this:
"6 months after AMD's announcement of Renoir, the number of 4000 APUs sold for desktops is literally zero (see how that works?) because TSMC is still slammed."
WaWaThreeFIVbroS - Thursday, May 21, 2020 - link
Your ignorance is amusingIt is technically a bribery
https://www.extremetech.com/computing/184323-intel...
Spunjji - Tuesday, May 26, 2020 - link
First 3 points: accurate, if not entirely on-topic. Nobody was charged with a crime, but Intel sure were fined a lot for collusion.Which gets to the 4th point: again, accurate, but not entirely relevant. AMD were definitely not able to match Intel for manufacturing, which is why they couldn't have beaten Intel out of the market entirely, but that was barely related to why they weren't getting into Dell systems. See the aforementioned proven-and-fined-for collusion.
drothgery - Friday, May 22, 2020 - link
Or because premium designs take longer when the new chip isn't just another respin of the same thing, and AMD hadn't produced a viable high-end notebook chip in well over a decade so it made sense to wait and see if Ryzen 4000 was any good rather than designing in advance?