CPU spikes HDN/PT Ultimate on new iMac pro
 

I'm currently running a brand new iMac pro 8-core, 64 gb ram, 2 tb ssd with hd native thunderbolt and a hd i/o 16x16. I'm setting my session to 24/96k and trying to track with no plugins at 64 samples in the buffer settings. I'm able to record just fine but I have noticed the cpu is in the upper 60's lower 70's. Is this normal? I spent so much on a brand new powerful iMac pro to have it not be able to handle what i'm throwing at it. I have my ram set to 32 gb in the playback engine. Any suggestions?

Re: CPU spikes HDN/PT Ultimate on new iMac pro
 

Spikes ? But then you just describe high meter values.

Stop looking at the CPU meters. I will betyou they are not telling you anything useful, especially with hyperthreading enabled.

64 sample buffer may or may not be usable, depends on lots of things. Sample rate, systems optimization, phase of the moon,... Worry about it when you get CPU related AAE errors (those errors are very different from what you can tell by looking at CPU meters).

If you are on Mojave disabling hyperthreading may help significantly with CPU errors, lots of discussion on DUC about this. Will also change significantly what you see in CPU meters.. but they are lying anyhow.

Re: CPU spikes HDN/PT Ultimate on new iMac pro
 

You have “RAM” set to 32 GB... you mean the disk cache set to 32GB? That is OK if you are dealing with sessions of that size, many people have smaller sessions. As a sanity check look at the total size of your large sessions on disk and set the disk cache to that. Only really an issue if you need. More memory for VIs etc.

Re: CPU spikes HDN/PT Ultimate on new iMac pro
 

The session i'm working on now is around 20GB. I am running on Mojave and tend to not want to mess with my cpu settings with a 3rd party app.

Re: CPU spikes HDN/PT Ultimate on new iMac pro
 

If you are running on Mojave and experience CPU errors you will likely need to disable hyperthreading, or... find a different DAW. This may get better when 2019 is released, small IO buffer issues was a specific problem Avid has called out with Mojave and not officially supporting that.

Using a "third party" app to disable hyperthreading has nothing to do with anything, it's just an easy way to use a tell the CPU to stop using stupid hyperthreading and behave in a more sane way. Go read all the posts from the folks on DUC who have report *great* results on Mojave from disabling hyperthreading. You came asking advice, you are free to ignore it if you want, but we're all also free to make fun of you if you ignore it and have any actual CPU problems...

Re: CPU spikes HDN/PT Ultimate on new iMac pro
 

I'll give it a shot tomorrow.

Re: CPU spikes HDN/PT Ultimate on new iMac pro
 

As you had already stated in a previous response that avid has stated issues with small buffer sizes and Mojave. I have found this right on the system requirements page for pro tools on Avid's site:

"ALERT: Do not upgrade to macOS Mojave version 10.14
Initial testing of Pro Tools with macOS 10.14 has shown serious problems with CPU performance at lower buffer sizes. Avid is working to find a resolution for this problem. It is recommended that users refrain from updating to 10.14 until further notice. If you have to use 10.14 then make sure to avoid lower buffer sizes (64 samples or lower at 48kHz, 128 samples or lower at 96kHz, 256 samples at 192kHz)"

Hopefully they fix this with an update soon!

Re: CPU spikes HDN/PT Ultimate on new iMac pro
 

Yes, that’s it, this is very old news that many of us here are well aware of... disabling hyperthreading was a wonderful discovery somebody made and reported here, it makes a big difference for CPU issues... which to be clear you are not actually seeing yet, but there is really no reason to run on Mojave right now with HT enabled... even if working better (in a 2019 release???) HT likely provides a relatively small improvement for many workloads. Nothing like the 2X implied by marketing fantasy or CPU meters...

Re: CPU spikes HDN/PT Ultimate on new iMac pro
 

Turns out I am getting CPU errors when trying to run at 256 or 128 with 14 plugins enabled. CPU shows around 20% but abruptly stops whenever it decides. I need to try with hyper threading off now.

Re: CPU spikes HDN/PT Ultimate on new iMac pro
 

Test with hyper threading off proves to be MUCH more stable than with hyper threading on. I'm well past 10 minutes of recording with all 14 plugins enabled and running at 64 buffer without a cpu error yet. Dosen't hurt to note that the pro tools cpu meter is massively incorrect as you have stated before in this thread. My activity monitor shows 7% when recording and pro tools shows around 20-30%. Looks like avid needs to provide an update for this crap! Haha.