Which new CPU for max power efficiency?

[fe0109]

Hallo,

with which cpu I achieve the best power efficiency under handbrake:

https://skinflint.co.uk/?cmp=2057517&cm ... mp=2057516

I want to use an integrated GPU, so I dont want to use an AMD CPU. And no "K" suffix (>65W), beacuse the CPU's without have a better power efficiency.

Thanks in advance!

[Woodstock]

There have been previous articles on this. And your question is very vague.

"Lowest power" is probably still one of the ATOM processors with QSV, but you are limited to the quality of an older QSV chipset.

Oh, you wanted some speed, as well? The QSV hardware on the selection of CPUs you chose works at about the same speed and power consumption. And, with software encoding instead of hardware, 8 cores is better than 6.

[fe0109]

Thanks for your response Woodstock.

Sorry that my question was vague.. I asked for the best power efficiency for h.226 and HEVC encoding with handbrake.

[fe0109]

No one a recommendation?

[mduell]

There's not going to be much difference between the options you presented.

[s55]

Also note, 65W is usually defined at a Base Frequency, so expect significantly higher than this under high load unless the cooling can't manage.

Either way, the 9900 will probably trend highest then it's a toss up between the other two. Probably not a major difference. The electricity cost is probably minimal difference.

[fe0109]

Thanks for your responses!

The 9900 has 8 cores and 16 threads. Does Handbrake work with 16 threads same efficiency as with 8?

[mduell]

With the same 8 cores you'll generally get better efficiency with the 16 hardware threads than 8 hardware threads. You won't get double the performance.

[fe0109]

If I understand you correctly, should that be an advantage of the 9700 (8 cores, 8 threads) over 9900 (8 cores, 16 threads), correct?

[BradleyS]

No, rather they will probably be about the same. Pay attention to cores, not threads.

[mduell]

If I understand you correctly, should that be an advantage of the 9700 (8 cores, 8 threads) over 9900 (8 cores, 16 threads), correct?

You do not, and that is not the case. 8 cores/16 threads is slightly higher efficiency, and thus slightly higher performance, than 8 cores/8 threads for typical HB encodes.

[fe0109]

Now I'm a little confused, as the last two posts seem to contradict each other.

[BradleyS]

Key word is slightly. Perhaps do some research on hyperthreading.

[mduell]

Now I'm a little confused, as the last two posts seem to contradict each other.

Slightly higher and about the same are consistent with each other.

The cores matter most, the threads only matter a little.

[fe0109]

Thank you, now I understand it correctly!

I have found some benchmarks on anandtech.com:

Handbrake Encoding Tests

720p60 at 6000 kbps constant bit rate, fast setting, high profile, frames per second
i9-9900k 212 (100 %)
i7-9700k 208 ( 98 %)
i7-8700k 159 ( 75 %)

1080p60 at 3500 kbps constant bit rate, faster setting, main profile, frames per second
i9-9900k 229 ( 100 %)
i7-9700k 194 ( 84 %)
i7-8700k 174 ( 76 %)

1080p60 HEVC at 3500 kbps variable bit rate, fast setting, main profile, frames per second
i9-9900k 226 ( 100 %)
i7-9700k 196 ( 87 %)
i7-8700k 175 ( 77 %)


Power Consumption

Full Load (Watts)
i9-9900k 168 - 100 %
i7-9700k 124 - 73 %
i7-8700k 145 - 86 %


The benchmarks unfortunately are for the K-suffix with 95W, but i guess the performance ratio to power is approximately the same for the 65W.

It seems that the 9700 has the best efficiency.

[mduell]

If they're the same power, and the 9900 has better performance, then the 9900 is more efficient.

[fe0109]

At the anandtech benchmarks the 9700 has an average performance of ~ 90% of the 9900, but only 73% power consumption

[mduell]

That's just the CPU, you need to add the rest of the system (which will be roughly the same in all cases), bringing the percentage difference down to be closer to the performance difference.

[fe0109]

I thought the values were for the whole system.

But my remaining components are sparingly anyway: Mainboard, RAM, one SSD (0.33W operation, 0.14W idle) and no graphic card.

[mduell]

It says package only on the webpage.

You also have the power efficiency of the PSU; as the power consumption goes up, as does efficiency generally, until you get very close to the max capacity of the PSU.

[fe0109]

Ok, so you think that with these factors the 9900 is more efficiency?

[rollin_eng]

I did some rough math on cost recently, 300w running 24/7 costs approx $1 per day, so depending on your electricity costs it may not be worth bothering about (not counting environmental costs, but you could probably get better results elsewhere).

[mduell]

Ok, so you think that with these factors the 9900 is more efficiency?

I think what I said the first time:
There's not going to be much difference between the options you presented.

[fe0109]

I will order the 9700! I think for encoding the 9900 is not worth the extra price and maybe i will aviod heat issues with my CPU cooler.

Thanks for all your help!

[Woodstock]

That's an AWFULLY small cooler; you are going to want to make sure you are evacuating the hot air out of the case quickly for that to work, even with a 65w TDP CPU.