Mojave & hyperthreading off

[Sugarnutz]

I'm fairly new to MacOS, but getting used to it. Over the years as a PC guy I a lot of times would get i5 CPUs as they had no hyperthreading and I was schooled that hyperthreading was useless, just giving you double the cores at half the speed really amd they were virtual, meaning fake which leads to instability. Glad the Mac crowd is learning this.

[AlexLakis]

Been running tracking sessions for the past few weeks with zero AAE errors at a buffer size of 64 (44.1/24) on Mojave with Pro Tools 12.6 on a new Mac Mini. 16 tracks, 4 auxes for headphones, VMR w/ mic/pre modeling on every track. Disabling hyperthreading was definitely the key. Hopefully official support for Mojave will come soon so I can get a little processing power back (haven't needed it so far!)

[JFreak]

Originally Posted by AlexLakis

Hopefully official support for Mojave will come soon so I can get a little processing power back (haven't needed it so far!)

Are you sure you have lost any processing power by disabling HT? Because, after all, everything you process happens on a REAL core and not a logical one.

HT is supposed to find out when a real core is idling and have another job waiting for that idle moment... which is great for offline work, but if you need realtime performance, it can actually worsen things, because every time you have more than one processing queue, you need to have a controller process to decide what goes where for processing, and that extra process also needs processing time. So somewhere along the way comes the point where adding more processing queues (logical cores) is counterproductive when you need to get things processed in very short timeframe (...and if you don't, the playback/recording stops).

Maybe you said it yourself; you are happy with 64 buffer performance having disabled HT but having it enabled gives you trouble. If realtime performance is what we're talking about, then no, you haven't lost performance but instead got it back.

[jwilkers]

Just out of curiosity, as I have been following this thread for a long time, is this only for HD users or everyone?
Seems everyone in here has HD.

[Emi]

No, regular Native PT here.

[AlexLakis]

Originally Posted by JFreak

Are you sure you have lost any processing power by disabling HT? Because, after all, everything you process happens on a REAL core and not a logical one.

HT is supposed to find out when a real core is idling and have another job waiting for that idle moment... which is great for offline work, but if you need realtime performance, it can actually worsen things, because every time you have more than one processing queue, you need to have a controller process to decide what goes where for processing, and that extra process also needs processing time. So somewhere along the way comes the point where adding more processing queues (logical cores) is counterproductive when you need to get things processed in very short timeframe (...and if you don't, the playback/recording stops).

Maybe you said it yourself; you are happy with 64 buffer performance having disabled HT but having it enabled gives you trouble. If realtime performance is what we're talking about, then no, you haven't lost performance but instead got it back.

Hey, J! Thanks for the refresher!

I am able to run less plugins with hyperthreading disabled so, yes, it is a performance hit. Like you said, I'm normally not maxing out on plugins when I'm finding I need lower buffer sizes, but sometimes I am (tracking at the eleventh hour...it happens), so I would like the power back.

Hyperthreading never gave me a problem on my mid-2012 Macbook Pro running OSX 10.8.5 up to OSX 10.12.5, so take that for what it's worth as well.

[arche3]

I stopped using disable hyper threading using 2018.7. High Sierra. Hdx.

Was a slight improvement disabled but even without I'm not getting CPU errors so not worth hassle for me now.

[neilvg]

Just to revive this thread - running High Sierra with a 12 core Cheese Grater (2010). Since upgrading to ultimate HD, have been noticing more and more random CPU instability issues - spikes, and random 'clocking' errors. I can get by with mixing, but tracking can be scary. Recently added a summing mixer and noticed with the incoming PRINT track added, more CPU clocking / spikes errors.

Finally remembered an old trick and disabled hyper threading. Viola! Pro Tools now displays CPU percentage much more accurately, and doesn't spike so much as fills up to near 100% before things stop (which of course is reasonable).

What tipped me off to do this was when I had nothing except two Acustica audio plugins enabled - and only 2 tracks. I was getting these intermittent CPU spikes that were coming from 15% CPU utilization to BAM -> RED ZONE. I would wait a bit for things to calm down, and it would work again.. but if I moved buttons or knobs around too much.. same thing.

Finally, disabled hyperthreading and, like a miracle you forgot you already knew about, suddenly everything worked, and I could run both plugins fine. Opened up a regular session and everything felt more stable and snappy.

So... Hyperthreading off for me! Wish more people knew about this. I thought I might have a Video Card Conflict issue before remembering about this... will do more testing... but it feels good to feel like things are more stable.

Neil

[JFreak]

HT issues have been much lesser since 2019.5


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[neilvg]

Running 2019.6 and it's WAY better with HT Disabled

I wonder what the expected gains of having HT on for realtime applications is. Doesn't make sense.