Setting CPU core count with a twist

[Nick]

Peter, All,

I have come across some settings that have a really significant and generally posertive impact on sound quality. Might even be a candidate to look into / exploit in 2.11.

It relates to varing the number of active CPUs set in BIOS. Its well documented that the number of CPUs cores set active in BIOS can be used to tune sound, particually the case for 621 chipset montherboards.

The following simple additional step to core setting really supercharges the effect, certainly on a 621 motherboard which is what i'm using here at the moment.

There are two steps:

1) set the BIOS to a desired number of processors cores and tell XX/OS software that this has been done via reboots into XX un-minimised full OS mode. Nothing new at all in this step.

2) now add a futher processor core in BIOS setting but do NOT tell XX/OS sofware that this extra processor has been added by NOT doing the reboots into full OS mode.


To explain the the setting applied by the steps in a little more detail

Step 1)

Go into BIOS and set a number of active processors. The number of cores you select has to be at least 1 processor core less than the maximum for the CPU. So in my case with a 16 core 6130 cpu, for step 1) I can set the number of CPU cores  anywhere upto 15 for this first step. After setting the cores in BIOS, reboot XX / OS back to XX unminimised level so that the OS / XX recognizes the new number of cores that have been set by the BIOS. Now go back into XX minimised OS ready to play music as normal. All this is just the normal approach to changing the number of cores used be the PC for XX music playback.

Its a good idea to play some music now just to listen to how this sounds before the next step is applied just so that you can appreciate the change the step 2) brings.


Step 2)

This is the extra step. Now go back into BIOS and add one extra core to the number set in step 1). In my case with my 6130 set in step 1 to 15 cores I now set the core count to 16 in bios, save this and reboot. (The key here is just play immediately dont go through the reboots to tell XX and the OS of the change to add this extra core).

Now listen again.

Having applied this, in my system everything tightens up throughout the spectrum, highs are particually improved with real shimmer and sparkle. Speed and dynamics are excellent and the "realness" level of the music takes a nice step forwards. Its not a subtle change.

So far I have tried the setting with 15 cores in step 1) and 1 additional core added by step 2). I won't go into the detail of why but I suspect other combinations such as 10 cores step 1) and 1 core step 2) etc will also produce a similar effect, but as long as its just 1 additional core added in step 2) I think this should work.

It would be interesting to hear what people make of this way of setting cores.

Best regards,

Nick.

[PeterSt]

So Nick,

Ready for this ?

This is undoubtedly the same, although I must check your procedure in detail to confirm it. Is in due 2.11 for more than a year now.
I seem to have trouble with finishing off 2.11.

The ones denoted with * are not really available software wise (XXHighEnd) - also see more below.

My procedure seems to be the other way around, but I think comes net down to the same; set to max in the BIOS and now software-wise shrink the number. As you can see I have a 28, set to 20.
Ultimately I could set the BIOS to e.g. 22, and have an other sound with software setting to 20.

Notice : you can only choose from the ones yo see in the list, because the software does not support other settings. E.g. 22 is not support to really utilize in the software. If you'd attempt that anyway, things may go bananas (like more threads (or less) are being dedicated to the available cores.

Hey, thanks for sharing !
If your procedure appears to be an other one, I suppose I can build that in too. We are used to all the existing parameters by now, right ? haha - We can really use more combinations.

Best regards,
Peter

[Nick]

Peter,

I have a big smile here, so funny that we have spotted the same somewhat convoluted, though important, cpu setting :-).

Reading your post I think we are doing the same thing just that I have to use the reboot (6 times :-(  ) to tell XX what how many cores to conifigure. Your software setting looks so much better to use !

I'v been playing with this for a while but didnt want to over complicate the post with other combination settings that have been tried, there are a lot but sometimes it feels like a logic starts to emerge (then disapears... haha hours spent trying this out).

I have a couple of questions, if you don't mind.

Are the numbers in your pick list screen shot above the number of physical cpu cores being set in your XX code or the number of hyperthreaded cores ?

Also you mentioned in your post above that the software just does not support some CPU numbers. Is this also the case in version 2.10c. It would help to know what numbers of cores might behave strangely as somtimes as I have tried out sequences say 10 cpus known to XX then adding cores one by one in BIOS there has been a progressive sound change then a sudden jump. It would be go to know what core numbers might act oddly ?

Final thought is, yes there are lots of settings, but IMHO that is still one of the strengths of XX. Certainly listening here this cpu setting seems to hold real potential and that is just with my basic approach.

I would certainly like to really encorage you to finish 2.11 I know its a huge effort to complete a release and then support it as it goes out but I'm sensing that from a sound quality point of view 2.11 could be a very very rare vintage 

Kind regards,

Nick.

[Robert]

Hi Peter, Nick,
                   Well I tried it and it does work. Mind you I only have 4 cores and reduced to 3, rebooted XXhighend in base no min OS.

Just a query I did toggle time performance and time stability. Does this realign/reset cores in Xxhighend?

Anyway I reset cores back to 4 and tried a song in Base, no min OS and yes certainly has a very positive improvement to sound. I agree it has sped things up, no error message at playback start now. Processes work quicker in Xx now. More music.

Bios questions:

Do you sync all cores or set core ratio for individual cores? Mine is set at sync but did not do a comparison.

Also have you tried hyper-threading off? Mine is on.

Some also suggest turn all C states off.

Certainly looking forward to 2.11 keep going Peter.

Robert

[coliny]

Peter, All,

I have come across some settings that have a really significant and generally posertive impact on sound quality. Might even be a candidate to look into / exploit in 2.11.

It relates to varing the number of active CPUs set in BIOS. Its well documented that the number of CPUs cores set active in BIOS can be used to tune sound, particually the case for 621 chipset montherboards.

The following simple additional step to core setting really supercharges the effect, certainly on a 621 motherboard which is what i'm using here at the moment.

There are two steps:

1) set the BIOS to a desired number of processors cores and tell XX/OS software that this has been done via reboots into XX un-minimised full OS mode. Nothing new at all in this step.

2) now add a futher processor core in BIOS setting but do NOT tell XX/OS sofware that this extra processor has been added by NOT doing the reboots into full OS mode.


To explain the the setting applied by the steps in a little more detail

Step 1)

Go into BIOS and set a number of active processors. The number of cores you select has to be at least 1 processor core less than the maximum for the CPU. So in my case with a 16 core 6130 cpu, for step 1) I can set the number of CPU cores  anywhere upto 15 for this first step. After setting the cores in BIOS, reboot XX / OS back to XX unminimised level so that the OS / XX recognizes the new number of cores that have been set by the BIOS. Now go back into XX minimised OS ready to play music as normal. All this is just the normal approach to changing the number of cores used be the PC for XX music playback.

Its a good idea to play some music now just to listen to how this sounds before the next step is applied just so that you can appreciate the change the step 2) brings.


Step 2)

This is the extra step. Now go back into BIOS and add one extra core to the number set in step 1). In my case with my 6130 set in step 1 to 15 cores I now set the core count to 16 in bios, save this and reboot. (The key here is just play immediately dont go through the reboots to tell XX and the OS of the change to add this extra core).

Now listen again.

Having applied this, in my system everything tightens up throughout the spectrum, highs are particually improved with real shimmer and sparkle. Speed and dynamics are excellent and the "realness" level of the music takes a nice step forwards. Its not a subtle change.

So far I have tried the setting with 15 cores in step 1) and 1 additional core added by step 2). I won't go into the detail of why but I suspect other combinations such as 10 cores step 1) and 1 core step 2) etc will also produce a similar effect, but as long as its just 1 additional core added in step 2) I think this should work.

It would be interesting to hear what people make of this way of setting cores.

Best regards,

Nick.

Curious as to what is happening here, after step 2 Windows sees all the cores again so nothing different as far as Windows is concerned (Windows always boots to what is set in bios). Maybe XX 2.10 runs differently I don't know.

Anyway my test will be to Unminimize OS & minimize it again without changing bios and hear if sound quality changes/gets worst.

Regards
Colin

[Nick]

Hi  Colin,

I agree windows should boot and configure to what is in BIOS provided but a few things might prevent this and I did not know these things might be done when I outlined step 2.

Provided that Peter is not; intentionally setting the Windows processor count (see the windows BOOT menu dialogue) , or has not done something in his minimise script that stops windows reconfiguring to a new BIOS processor count, and the windows BOOT menu number of CPUs parameter remains set to ALL then I agree Windows will use all of the processors set in BIOS.

I don't know if any of the above is being done, so I was just being cautious in the description of step 2.

Best regards,

Nick.

[PeterSt]

Are the numbers in your pick list screen shot above the number of physical cpu cores being set in your XX code or the number of hyperthreaded cores ?

Also you mentioned in your post above that the software just does not support some CPU numbers. Is this also the case in version 2.10c.

Nick, disregarding your last post for now (I still must wrap my head around what you exactly do), the numbers I show are usable cores, thus Hyperthreaded if set to that (which in my example / case is so (Hyperthreaded On).

The numbers with the Asterisks could be set in the BIOS, but are NOT respected by XXHighEnd, and thus should *not* be set.
N.b.: The due 2.11 will not allow to select the not-recognized numbers (see again the Asterisks).

Best regards,
Peter

[Nick]

.....the numbers I show are usable cores, thus Hyperthreaded if set to that (which in my example / case is so (Hyperthreaded On).

The numbers with the Asterisks could be set in the BIOS, but are NOT respected by XXHighEnd, and thus should *not* be set.
N.b.: The due 2.11 will not allow to select the not-recognized numbers (see again the Asterisks).

Thanks Peter, this is just the info I hoped for, very helpful to know which cpu settings to avoid.

I have tried a quite number of combinations. They give a big change in sound quality and does seem to be some logic in terms of how sound is changed by the number of 'extra' cores used. 2/4 extra cores seems to be best in many cases.

Favourite setting for my 6130 CPU (with 16/32 cores) is BIOS set to 14/28 cores for XX minimization and then BIOS set to 16/32 for playing music. This gives a really clear lively and very musical sound.

Kind regards,

Nick.   

Note core counts above are written as the "physical / hyperthreaded" number.

[PeterSt]

Yes, strangely enough I came to the same conclusion. 2 or 4 cores not being active sounds the best;
Our nomenclature may be not the same, but for a 14/28 core, setting it to 10/20 sounds the best.

For others and for now : In the (ever) due 2.11, you can just set this number and reboot. Don't like it ? change the setting and reboot again. That is really all.

Peter