The Intel 9th Gen Review: Core i9-9900K, Core i7-9700K and Core i5-9600K Tested
by Ian Cutress on October 19, 2018 9:00 AM EST- Posted in
- CPUs
- Intel
- Coffee Lake
- 14++
- Core 9th Gen
- Core-S
- i9-9900K
- i7-9700K
- i5-9600K
Power Consumption
TDP or not the TDP, That is The Question
Notice: When we initially posted this page, we ran numbers with an ASRock Z370 board. We have since discovered that the voltage applied by the board was super high, beyond normal expectations. We have since re-run the numbers using the MSI MPG Z390 Gaming Edge AC motherboard, which does not have this issue.
As shown above, Intel has given each of these processors a Thermal Design Power of 95 Watts. This magic value, as mainstream processors have grown in the last two years, has been at the center of a number of irate users.
By Intel’s own definitions, the TDP is an indicator of the cooling performance required for a processor to maintain its base frequency. In this case, if a user can only cool 95W, they can expect to realistically get only 3.6 GHz on a shiny new Core i9-9900K. That magic TDP value does not take into account any turbo values, even if the all-core turbo (such as 4.7 GHz in this case) is way above that 95W rating.
In order to make sense of this, Intel uses a series of variables called Power Levels: PL1, PL2, and PL3.
That slide is a bit dense, so we should focus on the graph on the right. This is a graph of power against time.
Here we have four horizontal lines from bottom to top: cooling limit (PL1), sustained power delivery (PL2), battery limit (PL3), and power delivery limit.
The bottom line, the cooling limit, is effectively the TDP value. Here the power (and frequency) is limited by the cooling at hand. It is the lowest sustainable frequency for the cooling, so for the most part TDP = PL1. This is our ‘95W’ value.
The PL2 value, or sustained power delivery, is what amounts to the turbo. This is the maximum sustainable power that the processor can take until we start to hit thermal issues. When a chip goes into a turbo mode, sometimes briefly, this is the part that is relied upon. The value of PL2 can be set by the system manufacturer, however Intel has its own recommended PL2 values.
In this case, for the new 9th Generation Core processors, Intel has set the PL2 value to 210W. This is essentially the power required to hit the peak turbo on all cores, such as 4.7 GHz on the eight-core Core i9-9900K. So users can completely forget the 95W TDP when it comes to cooling. If a user wants those peak frequencies, it’s time to invest in something capable and serious.
Luckily, we can confirm all this in our power testing.
For our testing, we use POV-Ray as our load generator then take the register values for CPU power. This software method, for most platforms, includes the power split between the cores, the DRAM, and the package power. Most users cite this method as not being fully accurate, however compared to system testing it provides a good number without losses, and it forms the basis of the power values used inside the processor for its various functions.
Starting with the easy one, maximum CPU power draw.
Focusing on the new Intel CPUs we have tested, both of them go beyond the TDP value, but do not hit PL2. At this level, the CPU is running all cores and threads at the all-core turbo frequency. Both 168.48W for the i9-9900K and 124.27W for the i7=9700K is far and above that ‘TDP’ rating noted above.
Should users be interested, in our testing at 4C/4T and 3.0 GHz, the Core i9-9900K only hit 23W power. Doubling the cores and adding another 50%+ to the frequency causes an almost 7x increase in power consumption. When Intel starts pushing those frequencies, it needs a lot of juice.
If we break out the 9900K into how much power is consumed as we load up the threads, the results look very linear.
This is as we load two threads onto one core at a time. The processor slowly adds power to the cores when threads are assigned.
Comparing to the other two ‘95W’ processors, we can see that the Core i9-9900K pushes more power as more cores are loaded. Despite Intel officially giving all three the same TDP at 95W, and the same PL2 at 210W, there are clear differences due to the fixed turbo tables embedded in each BIOS.
So is TDP Pointless? Yes, But There is a Solution
If you believe that TDP is the peak power draw of the processor under default scenarios, then yes, TDP is pointless, and technically it has been for generations. However under the miasma of a decade of quad core processors, most parts didn’t even reach the TDP rating even under full load – it wasn’t until we started getting higher core count parts, at the same or higher frequency, where it started becoming an issue.
But fear not, there is a solution. Or at least I want to offer one to both Intel and AMD, to see if they will take me up on the offer. The solution here is to offer two TDP ratings: a TDP and a TDP-Peak. In Intel lingo, this is PL1 and PL2, but basically the TDP-Peak takes into account the ‘all-core’ turbo. It doesn’t have to be covered under warranty (because as of right now, turbo is not), but it should be an indication for the nature of the cooling that a user needs to purchase if they want the best performance. Otherwise it’s a case of fumbling in the dark.
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DominionSeraph - Sunday, October 21, 2018 - link
The 8700k is also pulling 150W while the 8086k is 95W. Something's not right there._mat - Wednesday, November 7, 2018 - link
There can be two reasons why that is the case:1) The mainboard settings for Power Limits were different.
2) The 8086K ran into Power Limit 1 while the 8700K was not.
Whatever is the case here, it is no doubt that the 8086K did run into Power Limit 1 after the "Time Above PL1" (= power budget) was depleted. The 95 Watts are exactly the specified TDP of the CPU and Intel recommends this as Power Limit 1 value.
So the problem here is that the Power Limits and Current Limits of the mainboard are not properly documented and seem to differ between the test candidates. While the 8086K obviously had Power Limits in place, the 9th gen CPUs were benched with no limits at all (only temperature limit at 100 °C on a core).
Also, the whole page on power consumption needs rework. The TDP does matter depending on the board and its default settings.
ballsystemlord - Sunday, October 21, 2018 - link
Ian! Many of your tests ( Y-Cruncher multithreaded, apptimer, FCAT - ROTR, WinRAR ), are taking too short of a time. You need some differentiation here! Please make them harder.R0H1T - Sunday, October 21, 2018 - link
>In case the previous comment was missed.I see that the last few pages have included a note about Z390 used because the Z370 board was over-volting the chip? Yet on the Overclocking page we see the Z370 listed with max CPU package power at 168 Watts? Could you list the (default) auto voltage applied by the Asrock Z370 & if appropriate update the charts on OCing page with the Z390 as well?
mapesdhs - Sunday, October 21, 2018 - link
"Intel has promised that its 10nm manufacturing process will ramp through 2019, ..."Ian, what promises did Intel make 2 years ago about what they would be supplying now?
eastcoast_pete - Sunday, October 21, 2018 - link
My guess is that Intel is now printing those promises in 10 nm font size (easily readable with a standard electron microscope). See, they moved to 10 nm by 2018!ballsystemlord - Sunday, October 21, 2018 - link
Actually, fonts are measured in points. So, it's 10pt, and it's rather legible.But, as for products, I don't see any either.
darkos - Sunday, October 21, 2018 - link
nice review, but: please add a flight simulation such as x-plane and prepar3d or fsx. this is an area that is sadly, missing from your reviews.kasboh - Monday, October 22, 2018 - link
Do I see it correctly that there is little benefit of HyperThreading with 8 core CPUs?eXterminuss - Monday, October 22, 2018 - link
I am quiet shocked to see that Anandtech is using a vastly outdated and in parts plainly wrong description for World of tanks:1. The enCore engine ist being used in world of tanks for quiet a while now (10 month)
2.World of tanks is a free to play game, no elements hiden behind a paywall, e. g. no more features for a paying customer than for a freelooter.
3. Since the outadted EnCore benchmark was used, i would have at least expected to see the Results of that benchmark being posted aswell.
Sincerly yours,
eXterminuss a World of Tanks Player