Latency, LatencyMon and Audio Engine dropout

[Harley Dear]

@Noel Borthwick At the risk of sounding real thick, is this is what you mean by "Also run with MMCSS enabled in Cakewalk."

Just wanting to make 100% sure ?

 

[Jim Fogle]

Here is one more laptop power management tip for your consideration.  Many Microsoft Windows updates reset some of your laptop configuration settings.  All power management settings (USB controller, Power & Battery, etc.) seem to be the worst offenders with onboard audio bit depth and sample rate settings a close second.

[bitflipper]

MMCSS is a feature of the Task Scheduler, the part of Windows that decides what the CPU should be doing right this millisecond. Windows is constantly juggling multiple tasks, and it's up to scheduler to make sure that tasks that need handling right away get their shot while low-priority tasks don't get ignored. It's a tricky business, and entire books have been written about the subject (which I have read so you don't have to).

By default Cakewalk uses an MMCSS profile that favors audio. This could reduce dropouts and/or allow smaller buffers if you're pushing the CPU hard. You would only disable it if some non-audio issue cropped up as a result. For example, it can hurt network performance, but that's not going to be an issue for most DAW users.

Apparently, some ASIO drivers like to tweak thread scheduling themselves, which is why applying MMCSS to ASIO is optional.

 

[Harley Dear]

Thanks for that information Bitflipper.

 

[Michael Richards]

On 1/12/2023 at 3:26 PM, bitflipper said:

MMCSS is a feature of the Task Scheduler, the part of Windows that decides what the CPU should be doing right this millisecond. Windows is constantly juggling multiple tasks, and it's up to scheduler to make sure that tasks that need handling right away get their shot while low-priority tasks don't get ignored. It's a tricky business, and entire books have been written about the subject (which I have read so you don't have to).

By default Cakewalk uses an MMCSS profile that favors audio. This could reduce dropouts and/or allow smaller buffers if you're pushing the CPU hard. You would only disable it if some non-audio issue cropped up as a result. For example, it can hurt network performance, but that's not going to be an issue for most DAW users.

Apparently, some ASIO drivers like to tweak thread scheduling themselves, which is why applying MMCSS to ASIO is optional.

 

I understand the task scheduling, but I ignorantly never looked up what MMCSS does. I'm going to spend some time with it unchecked to see if it interferes with ASIO and my RME interface with is quite nice for USB2. Just goes to show the value of good programming.

Michael

[bitflipper]

By all accounts, RME has the best drivers. I've never been in a position to afford RME, but I've read technical papers from them and I believe those guys are some serious bit-flippers. 

Also don't overlook WASAPI.  It's what I've used for about the last 4 years after a long, long time with ASIO. Give it a try.