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Old 20th September 2019
Originally Posted by RyanC View Post
From what I've gathered from @ ProPower who's measured with a function generator-

@44.1/48 HDX is 1.9 with only an audio track, 2.5ms with one send and submix and ~10-100 samples per plugin monitored through, so depending on plugins 2.7ms to 4.7ms. HDN is 3.35ms at the 32 sample buffer and most plugins add 0 samples.

@ 96k HDX is .45 only an audio track, ~1ms with one send and bus and plugins adding from .1ms to another 1ms, so 1.1ms to 2ms. HDN is 1.8ms @64 buffer.

But HDX also increases RTL with more auxes and busses...not by a lot, but in these margins even an .5 ms increase is significant. Adding submixes and auxes has no effect on RTL for native. Maybe ProPower will chime in with more details.

Of course it's true that you have to run the lowest buffer settings, but this is no issue on my 7980xe systems if the sessions don't have VI's or if you freeze the VI's. I wish there was an option to have double or even quad buffer settings for VI's in PT.

It is true that CPU use goes up dramatically when you go from the 128 buffer to the 64, from 64 to 32 isn't as dramatic, so there is some threshold there (at 44.1/48). From what I can see tinkering with 2caudio breeze, support for AVX 512 seems to make a solid improvement there...IE less of a jump going from 128 to 64 and then 32. I wasn't able to test it before and after though so this is a bit conjecture. I will say that at the 32 sample buffer plugins have to be coded well, some plugins, in spite of having plenty of CPU overhead, will not run cleanly at the lowest buffers.

Originally Posted by ProPower View Post
Its getting to be a while since I had HDX but Ryan C looks mostly correct.

1ms tracking on HDX at 96kHz with careful plugin choices is totally doable. I have only tracked at 96kHz for last 5 years for for RTL reasons so can't comment on how long one can maintain 32 buffer at 44.1.

At 96kHz I find 32 buffer (not available in PT) very hard to sustain and virtually every high quality Reverb throws pops and clicks in. In S1 it is close to working but still not. Buffer 64 same result. Only gets good with buffer 128 - 256. RTL is then in the >3ms range - doesn't work for me.

With Native I rely on Interface DSP - today have both Antelope and Apogee. Both deliver <0.5ms RTL at 96kHz. Plugins are limited to what they support for this function. With the Apogee version super limited on plugins (and forever in Beta) but I have a working workflow with Logic that is as close to HDX as I have found.

All that said - these DSP assist workflows are really only good for singe monitor mix situations. Once multiple monitor mixes are needed - I would wish for HDX above all others...

Originally Posted by ProPower View Post
Yes - I too struggle with the reality of physics and the numbers in that I sing between 6" (rare) and 1.5 feet from the Mic which totally effects the total RTL (Hardware + distance) and thus the comb filtering. In general I have little issues with 1ms RTL from the hardware. But it is so hard to get a full Native system to run there. I am sure 44.1 is better from the computer POV. Whenever I engage 2+ms from the hardware it is a big tonal change. Vocals is the most significant.

The 0.3ms I quote is analog to analog (measured scope and Function Generator) through the Apogee FPGA FX. Antelope is 0.3 + some for each added AFX.
All that sounds realistic - and I totally agree that the cuemixer workflow (I like UAD best) works great for single source overdubs with one monitor mix. As soon as you've got multiple performers or a large mic setup - it's a nightmare by comparison!