Power Consumption and Frequency Ramps

On the box, both processors are listed as having 65 W TDPs. With its Zen-based hardware, AMD has been relatively good at staying around that official on-the-box value, even during turbo. In the last generation, AMD introduced a feature called PPT, or Package Power Tracking.

  1. For 105 W processors, PPT is >142 W
  2. For 65 W processors, PPT is >88 W
  3. For 45 W processors, PPT is >60W

This allows the processor to raise its power limits, assuming it isn’t breaching thermal limits or current limits, and consequently raise the frequency. As a result, while we see 65 W on the box, the real world power consumption during most tasks is likely to be nearer 88 W, unless the current or thermal lines are crossed.

As a new element to our testing, we are recording power over a number of benchmarks in our suite, rather than just a simple peak power test.

AMD Ryzen 3 3300X

For the faster chip, we saw a peak power in both of our tests of around 80 W.

With yCruncher, which is somewhat of a periodic load, the power consumption dropped over time to nearer 75 W.

3DPM is more obvious with its idle steps between loads, being 10 seconds on then 10 seconds waiting. The power almost peaked at a similar amount here.

In both of these graphs, the package power when idle is around 16-17 W. I looked back through the data, and noticed that out of this power only 0.3 W was actually dedicated to cores, with the rest being towards the big IO die, the memory controllers, and the Infinity Fabric. That’s still pretty substantial for an idle load.

At low loads, the power per core was around 14 W, while at full load it was slightly less depending on the test. This is a bit away from the 20 W per core we get from the high end Zen 2 processors, but these only go to 4.3 GHz, not 4.7 GHz+. This is about in line with what we expect.

On our frequency ramp test, the Ryzen 3300X went from an idle state to peak power within 17 milliseconds, or approximately a frame at 60 Hz.

One of the new features with Ryzen 3000 is CPPC2 support, which AMD claims to reduce idle-to-turbo ramping from 30 milliseconds to 2 milliseconds. We’re seeing something in the middle of that, despite having all the updates applied. That being said, the jump up to the peak frequency (we measured 4350 MHz, +50 MHz over the turbo on the box) is effectively immediate with zero skew across a range of frequencies.

AMD Ryzen 3 3100

Given that the TDP number on the side of the box says 65 W as well, any reasonable user would assume that the power of this chip would be equal, right? Regular readers will know that this isn’t always the case.

In our yCruncher test, because the turbo frequency is lower than the 3300X, it means the voltage can be lower, and thus power is lower. Our history of testing Zen 2 has shown that these cores get very efficient at lower frequencies, to the point where our processor doesn’t even break that 65 W threshold during yCruncher.

Similarly the 3DPM peaks are also lower, barely going to 55 W during an AVX2 workload.

On the frequency ramp side, we see another instance of a 16-17 ms transition.

Summary

For the peak power out of all of our testing, we saw the Ryzen 3 3300X hit a maximum of 80 W, and the Ryzen 3 3100 go to 62 W. When we compare that to the Core i7-7700K, at 91 W TDP / 95 W peak, combined with most of the results on the next few pages, AMD by comparison is more efficient.

AMD Ryzen 3 3300X and 3100 Review Test Bed and Setup
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  • ksec - Thursday, May 7, 2020 - link

    It was only yday I asked on forum what is happening to Intel 7nm CPU. We know Tiger Lake is coming, then there is Alderlake. And that is it.

    Again, despite all these, AMD needs to "sell" better. The results from their quarterly report are no way near good enough.
  • outsideloop - Thursday, May 7, 2020 - link

    Hardware Unboxed includes the 9th Gen i3 and i5 parts against these new Ryzens, in their testing.
  • CrystalCowboy - Thursday, May 7, 2020 - link

    About the test setup: No PCIe 4.0 graphics cards. No PCIe 4.0 NVME SSD. You are handicapping these CPUs by not letting them take full advantage of their features. If an older or lesser CPU cannot support these features, well then it deserves to score lower for it. You did use DDR4-3200 RAM, thanks for that.
  • Ian Cutress - Thursday, May 7, 2020 - link

    Users with a $99 CPU are going to use a PCIe 4.0 SSD? really?
    How do I keep the storage element consistent between tests then, to make sure I'm actually testing the CPU? How do I keep that storage constant for CPUs 10 years ago?
  • Makaveli - Thursday, May 7, 2020 - link

    Yup Ian,

    That complaint is ridiculous, almost no one is going PCIe 4 storage in a budget build.

  • MDD1963 - Thursday, May 7, 2020 - link

    can't wait for a water block equipped X570 for $800 and the R3-3100 to get the best OC's possible with muh PCI-e 4.0 storage......!!!! :) (Who cares if PCI-e 4.0 drives sometimes fare 1-3% worse than the 970 EVO in some real world comparisons!)
  • eastcoast_pete - Friday, May 8, 2020 - link

    Maybe it's because after buying a PCIe 4 capable MB and a PCIe 4 SSD, I wouldn't have any money left to buy a CPU for more than $ 100? Kidding, of course, this challenge makes no sense.
    That aside, it would be interesting to see what kind of CPU can actually make good use of PCIe 4 capable MBs and fast storage.
  • Deicidium369 - Friday, May 8, 2020 - link

    $500 Car w/ $10,000 rims
  • MDD1963 - Thursday, May 7, 2020 - link

    Yes, PCI-e 4.0 SSDs would have help *so much* on ... gaming frame rates.... <exaggerated overtly obvious eye roll> :)
  • eastcoast_pete - Thursday, May 7, 2020 - link

    Thanks Ian! If possible, please add some performance numbers for the current i3 and i5 in. Right now, AMD owns the below $200 space for desktop CPUs. Also, data from other websites that had some i5-9100 on hand show that the 3100 A.K.A AMD's leftover dies, are outperforming Intel's offerings here.
    Really hope Intel steps up, and soon. I'm hoping to buy something later this year, so whoever gives me the most bang for my buck gets my money.

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