HD NATIVE vs HD TDM latency

[James Drake]

How is the analogue-analogue latency, via an RTAS plugin, on an HD TDM rig compared with HD NATIVE?

[albee1952]

Totally dependent on the plugin. Many RTAS plugins have zero or 1 sample of latency, while others have from 64 to several thousand samples of latency. In general, HD TDM hardware has slightly less latency than HD/Native, but working at the 64 or 32 buffer settings should be fine for most any application. Be aware that the older blue interfaces have slightly MORE latency than the new HD IO boxes

[BobbyDazzler]

Native is pretty quick if you watch what plugins you are using. I rarely have to use Low Latency Monitoring as a 32 or 64 buffer are fine.

[WernerF]

How big of a session can you run at 32? I get "running out of CPU" errors when I try to convert too many TDM plugins to RTAS on big sessions at 256. This is on an HD6 system running on a late 2008 quad core Mac.

[James Drake]

I'm interested in real numbers.

I understand the lowest buffer setting for Native is 32, and HD TDM is 64?

How does this really affect useage? With HD TDM does it mean each time you go to or from the CPU it takes 64 samples? So a round trip takes 128 samples?

With Native the handoff between the I/O and CPU only happens once for the whole session, so at 32 buffer the round trip is only going to be max 64 samples?

If you set the buffer to 64 and both have an HD I/O and only use RTAS plugins will there be any difference?

If "no" then why does HD NATIVE even exist?

[Darryl Ramm]

HD native exists to give a relatively reasonable cost/high performance I/o interface that has a future. TDM is on its deathbed, no support past Pro Tools 10. No 64 bit. And unfortunately the old TDM baggage has been holding lots of things up that people seem to want (64 bit memory, 64 bit mixing and float data formats, freeze tracks, fast printing, etc.). Given much of this the question almost is why was TDM held onto for so long?

Darryl

[seanpualion]

HD TDM latency is good...

[James Drake]

OK,

Looking at the machine now.

Pro Tools 10.2 HD4 Accel.

H/W Buffer size 64.

If I put Massey CT4 on an audio track as DSP (TDM) then it shows 5 samples delay. If I change it to NATIVE (RTAS) then it shows 1 sample delay. What is that about?

If I put a CT4 plugin on an aux track then as DSP it shows 5 samples delay, and as NATIVE it shows 165 samples delay. Where does that come from? That is more than double the H/W buffer.

Am I right in saying that, using a mixer with NO plugins, and the same interface:

HD NATIVE has the SAME latency as TDM, plus double the HW buffer size?

If you put just one RTAS plugin on an aux input then the latency of HD TDM and NATIVE is now actually the same? (but not EXACTLY the same?)

Audio tracks in HD TDM, actually less latent to use RTAS?

[getz76]

Originally Posted by James Drake

Am I right in saying that, using a mixer with NO plugins, and the same interface:

HD NATIVE has the SAME latency as TDM, plus double the HW buffer size?

HD Native and HD TDM are not the same interface, though.

See here: http://www.avid.com/static/resources...ilyLatency.png

[WernerF]

Remember that you loose HEAT if you go Native.