22/04/2015
Pro Tools | HDX systems
In October 2011 Avid introduced a new line of DSP accelerated cards, named HDX cards, along with version 10 of its Pro Tools software. The cards included DSP processors manufactured by Texas Instruments, operating with increased computational precision – 32 bit floating point versus the previous 24 bit fixed (in the older generation 56k chips made by Motorola). Benefits claimed for the new system included improved technical performance in terms of audio dynamic range, monitoring latency, and overall computational power, when compared to the older HD line.
In its marketing Avid aimed the HDX system at customers requiring the highest and most consistent practically achievable levels of technical performance. The practical benefit to the user was the more reliable creation of large and complex productions typical of those demanded in modern music production. A key stated benefit was near-zero monitoring latency.
The "HD" product line was reorganised to include "HD|Native" (without DSP) and HDX.
The HD|Native systems made use of the host system's CPU for all audio processing while retaining the augmented workflows and sound quality factors of Pro Tools HD.
HDX's primary advantage over HD remained the considerably lower latency for all DSP reliant operations. As a result, in order to maintain the required consistency of performance, HDX products were specified with a fixed maximum number of "voices" (audio tracks). Up to three HDX cards could be installed on a single system, for a maximum of 768 total "voices" (audio channels).
While by comparison, native systems from all manufacturers including Avid may offer an apparently unlimited number of tracks / voices, every system necessarily has practical limits to what can usefully be achieved, depending on technical specification of the host computer, software configuration and user preferences.
HDX systems accelerated digital signal processing for Avid's own AAX format plugins only. The company ended support for the older TDM technology for use with its HDX products. (TDM stood for Time Division Multiplexing; though it was sometimes known as Time Domain Multiplexing.)
Avid advised users that Pro Tools 10 would be the final release for Pro Tools|HD Process and Accel systems, and that its TDM technology would be discontinued.