Processor for ROCK (8th generation)

peter - thanks for the info and insight on the three options! i think i now have a good handle on this.

the T CPUs look to be quite similar in price but with the noted power / performance tradeoff.

interestingly, this tradeoff in the i3-8300T is rather small with the base speed still at 3.2GHz for 35W. also, the frequency / TDP can be down-configured to 2.5GhZ / 25W which is closer to being on par with the NUCs. looks like the best and a good option for my purposes.

unfortunately, the T CPUs are not due back in stock until late march at all the usual online sellers… so, on hold for a while unless anyone knows of another source?

If you’re aiming to upsample to DSD512 I’d say you will need to go for something more powerful than an i3, whatever generation. But, one the other hand, the Intels Speed-Stepping and throttling is very well executed in the 8th gen Core processors.

In the first post of this thread you can find some real world examples of processor and hardware performance, however only up to DSD128:

I have added most of these and just to clarify, the tests using my i7 8700 doesn’t seem too impressive by only judging from the figures in the spreadsheet. However, when upsampling to DSD128 the computer was just barely idling and the Speed stepping throttled the clock frequency way down.
(Which can be seen on then power consumption…)

given fanless, one is pushed to CPUs with low TDPs which in turn makes the intel T CPUs the best (only?) choice. and, from the discussion here the consensus seems to be that for DSD upsampling one wants a CPU with a high single core frequency…

of the three T CPUs available the i3 would seen to optimize on power / single core speed:

  • i3-8300T… 3.2GHz (3.2GHz max) / 4 core, 4 threads / 35W (25W) TDP
  • i5-8600T… 2.3GHz (3.7GHz max) / 6 core, 6 threads / 35W (25W) TDP
  • i7-8700T… 2.4GHz (4.0GHz max) / 6 core, 12 threads / 35W (25W) TDP

in any event, the i3 should otherwise more than meet my needs and if/where it falls short on dsd upsampling i will have to make do.

would be very interested to get your thoughts here.

I’m not entirely sure this reflects the real world scenario. If you use “Parallelize Sigma Delta modulator” in DSP Upsampling settings i seem to recall all cores of the i7 8700 were being utilized evenly.
(However, at DSD128 tasks they were nowhere near their max frequencies)
If i had a DSD unit that could do better than DSD256 i’d be glad to try it out for you and measure power consumption. (I have DSD256 options though)

this is interesting… and, is at odds with the consensus above - esp:

maybe roon can comment on the number of cores used both with and without enabling Parallelize Sigma Delta Modulator. also, maybe roon can comment on this thread in general with respect to which CPU characteristics are most important for a fanless ROCK to be on par with a nucleus+ …maybe, a set of minimum specs which must be met?

given that intel is continually updating / replacing their CPUs and that the ultra-low-power “U” CPUs are not available as a stand alone purchase as far a i know, such information would be helpful on an ongoing basis to the DIY community here.

not sure who to ping here but maybe @danny or @support can direct this to the best place.

thanks again peter! …question answered.

If you are determined to buy only from this set of choices and assume your fanless chassis is thermally capable to handle any of them: For DSP purpose in addition to upsampling, get the i7. Otherwise i5 seems to be a good cost/performance choice, as the 0.5GHz increase from i3 to i5 costs less than the 0.3GHz increase from i5 to i7.

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I’m having trouble finding the option to turn on Parellelize Delta Sigma Modulator in the new 1.6 UI. Where is it now?

thanks for the recommendation!

i am not necessarily determined to buy a T-designation CPU; however, they are the processors with the lowest TDP i can find that are available for stand-alone purchase – as far as i know anyway.

other suitable CPUs are available with 65W TDPs. maybe they are more “efficient” making their higher TDP less of an issue… but, this is way beyond my knowledge of the subject.

its also possible i am trying to fit a square peg in a round hole… maybe a NUC in another roon with a fiber run to an FMC or an opticalRendu just before the DAC is better and, perhaps, the path of least resistance?

There seems to be some misinformation in this thread about i7 being nessesary for upsampling to DSD512.
I use a AsRock Deskmini 110 with a 65W Kaby Lake i5-7600 which is a 4/4 core 3.5GHz base and 4.1GHz Max
When Parellelizise Sigma Delta mudulator is enabled the speed is usually 2.5 and never lower than 2.2
I do not use any room correction.

Check out this review.

It’s in the DSP settings for the device, under Sample Rate Conversion.

thanks for posting! quite useful real world performance data.

reviewer was using the i5-6500 processor which max’d out at dsd256 with no other DSP.

  • i5-6500: 4/4 cores, 3.2GHz base, 3.6GHz max, 65W TDP

by compairison the 8th gen version of this CPU:

  • i5-8600: 6/6 cores, 3.1GHZ base, 4.3GHz max, 65W TDP

the 8th gen version may or may not perform materially better - no way of knowing by the just the CPU specs alone. we are trying to hit a moving target here as intel upgrades / replaces their CPUs… which is why i think it would be helpful for roon to provide some guidance, minimum specs, etc. to help diy users choose the right CPU for their needs.

Paralysis of analysis.

I have 3 endpoints (grouped) that I upsample from 192K to DSD256 using a 7th gen i3 NUC running Roon under WIN10.

You didn’t say how big your library is, but the Roon Nucleus is only an i3 and is good for 6 endpoints and 100,000 tracks.

lmao!! very true.

otoh… measure twice, cut once.

library is currently ~10,000 tracks

I’ll post some screenshots later of pure Roon performance, as i have some video compression tasks running.
I run an Intel i7 8700 at standard speed (3.2Ghz, turbo up to 4.6Ghz for singular core) on an Asus Z-370P mobo. The CPU is aircooled with a std 120mm fan venting a 4 heatpipe cooler.
No, it’s not quiet, but not especially noisy either.
As i write this it is upsampling some Prodigy - The Fat Of The Land in RedBook to DSD128 at the same time as its using 4 cores for analysing my library (on an external 2.5" USB drive).
It is also compressing a BlueRay rip of Joe Bonamassa - Live At Royal Albert Hall (Handbrake, 1080p Super High Quality)
Before using Parallellize Sigma Delta modulator:

And after enabling Parallelize…

And just for fun, a look at the Windows Task manager:

Does this mean it is optimal or superfast? No, of course not, but i think it scales very, very good! Looking at the Asus AI Suite it indicates that the CPU is very steady at just under 65W power consumption. (It is a 65W TDP CPU, just like the ones you mentioned)

i5-7600 65W 4/4 core 3.5GHz base and 4.1GHz Max.
It is a MOCK build.
With parallelize Sigma-Delta:
DSD128 5.3x
DSD256 3.5x
DSD512 2.3x
DSD512 1.2x

So a 8th or 9th generation i3 would probably be close to my 7th generation i5 and both faster than a i7 NUC because of the higher TDP.
To me it looks like 4/4 cores is more than enough.

That seems low. I can do 44.1kHz -> DSD512 upsampling and DSD512 RAAT Playback to Lumin X1 or T2, with a processing speed of 2 from a Roon Core on i5-6600.

@aKnyght Re-evaluating the benchmarks again I’d like to correct the above to: don’t use anything less than an i5 for DSD512 upsampling.