Question about PCIe expansion for PT9 HD

[fm_xtk]

So - why can I easily run an instance of Altiverb with a 5 second reverb on RTAS, but it takes FOUR Accel chips just to run one 4.3 second TDM instance??? Doesn't make any sense to me. One HD Accel card originally cost twice the price of a Mac Pro. Shouldn't it have way more processing power?

It's not about the processing power but about the RAM on the cards. That's one of the reasons why i.e. Echoboy is limited to a delay time of 1000ms per TDM instance. The big convolution reverbs allow you to circumvent that limit by cascading chips. Running a convolution reverb on DSP chips was a necessity 10 or so years ago but not even my trusted old MacPro 2,1 was breaking into a sweat with 5 or 6 instances of TL Space Native in a mix. The biggest problem - as you have discovered - is the penally incurred when using RTAS plug-ins on Auxes. That's the one reason I have stayed away from UAD so far. I know the plug-ins are great but I will have to sacrifice a good few voices in a mix (probably something like 32 or so).

So I decided to go with TDM only as much as possible, also because it costs nothing these days. I use the OXF reverb a lot and you can get 2 full stereo instances per chip. That way I only need to dig out convolution stuff where it matters.

On a side note I am now much more old school about bouncing everything down as early as possible so the voice limitations aren't that big a deal for me anymore.

Well done on running your rig for ten years. I am planning to do the same with mine (see signature). It's all "legacy" but I think it may well outlast AVID.

There is one thing I regret about my Hackintosh and that is not having built now sooner. If you can put together a Pro Tools rig with cards you can build your own computer. It's not very hard at all. It takes time to research but you learn a lot along the way.

[innerbooty]

This is a fascinating and instructive conversation for me. I've struggled since I upgraded to HD to get to the bottom of exactly how plugins are allocated and resources used, and where the bottlenecks are. It's so hard to find clear explanations about exactly how HD card chips are used, and how RTAS plugs really work. Your explanation about RAM on HD chips makes sense, and helps fill in some gaps for me.

I think you mentioned thinking about HD Native as an option, which seems to make more and more sense as CPUs get more powerful. But isn't HD Native still just a glorified LE? Dont you still need to go into low latency mode when recording? And how does I/O to outboard work? Low latency? I use 8 channels of I/O for outboard inserts during mixing for all my sort of mission critical tracks. I like running TDM.

I've got a 2.66Ghz Quad Xeon with 12 GB RAM, which so far has been pretty great in terms of running RTAS, and just general processing. I run 16-channels of Apogee AD/DA16X and a 192 through a Ghost (mainly for monitoring). How much of a DSP / horsepower bump could I expect to get by going with one of the Hackintosh models you suggest?

Thanks again for all the tips!

[fm_xtk]

Originally Posted by innerbooty

But isn't HD Native still just a glorified LE? Dont you still need to go into low latency mode when recording?

It's not just glorified LE. It's basically HD without the dedicated DSP mixer and plug-in DSP. You have all the HD TDM software features. The big difference is

1. Maximum I/O is limited to 64 (TDM is 160)
2. All plug-in processing is carried out on the host CPU
3. Delay Compensation is tripled or quadrupled - not sure exactly how much but it's around 16000 samples if I remember correctly.

The host processing can be a curse but most people prefer the advantages of native procession for mixing. For recording it can be a pain in the neck as you will have to find a compromise between a low buffer and plug-in performance.

It's easy to add DSP processing using UAD of course and on HDN you will not be penalised for putting all those RTAS plug-ins on busses.

Like you, I like DSP and TDM systems. A typical mix I might do can have 120 tracks, 192 voice mixer, all cards maxed plus 5-6 VI's running live. I do that on the lowest buffer size the playback engine will allow (128 samples @192 voices) and my CPU is hitting 7-8%.

On my MacPro I used to run HD3, same mixer but I had to run the highest buffer size possible to accommodate for all the extra native processing I had to do on top of maxing out all three cards.

I hate how unresponsive and slow a Pro Tools 10 system becomes at high buffer settings. On the other hand I love how lean and snappy my current rig is. It is responsive, all cues happen instantaneously, etc.

Because of the way I work I could never settle on HDN. 64I/O just isn't enough for my workflow. But I won't be paying through the nose for HDX in order to have redundant DSP lying around as few manufacturers support the AAX DSP platform.

So I have settled for sitting it out on 10 for the foreseeable future. There are a ton of spares around and everything is dirt cheap. I do not need the extra features of 11 or 12.

If I ever go down the native route it will not be with AVID. In fact I can't see myself making any further investments in the company at all.

And how does I/O to outboard work? Low latency? I use 8 channels of I/O for outboard inserts during mixing for all my sort of mission critical tracks. I like running TDM.

Outboard works in the same way as on HD. No need for low latency. Everything is is automatically compensated for.

I've got a 2.66Ghz Quad Xeon with 12 GB RAM, which so far has been pretty great in terms of running RTAS, and just general processing.How much of a DSP / horsepower bump could I expect to get by going with one of the Hackintosh models you suggest?

That sounds like a MacPro 1,1 or 2,1. I used to have the same machine and my Hackintosh is just over twice as fast. I thought it was going to be faster but then I only have a single Hexacore. Having said that, I am over clocking it and it's killer with VI's - even on PT10 which is much, much worse for Vi's or native processing than HDN on 11 and above.

You should look into the performance difference between HDN on 32bit PT10 and 64bit PT11/12. People have reported a massive boost in performance on the same rigs due to the ability to switch off processing when no audio is running. I don't know if that makes things more laggy but for the vast majority of people it's a big gain.

[antonis]

Very interesting subject indeed!


I am coming towards this from a slightly different angle:

I will definitely take on board the Hackintosh advice and build one myself come 2016. I still use a HD3 system only for reverbs, stems recorder and on occasion, a Satellite video player. But I have to confess that somehow unfortunately I have been impressed by the new AAE and I've heard and noticed the sound improvement on the audio engine. From that point onwards I have been reluctant mixing 32-bit RTAS plugins with 48-bit "double precision" ones. Another parameter that might be coming in to play is that since my work is mainly for TV post, I work almost exclusively ITB. Hence, no analogue hardware"injection" anywhere in the path. So, I don't know whether the absence of analogue is what might make a difference - and make 32-bit rounding errors degradation apparent - or it is just something in my head. I just confidently hear that all sound in PT11 being clearer, "truer" to the AD/DA path.


As a result a did buy a HDN card, and potentially looking for a good deal on a HDX. But for the time-being, Revibes, TL Space and Altiverb 6 on the HD3 and will expand to more cards after fm_xtk's recommendation to add more TDM instances and minimise the I/O TDM chip impact.


Also, since I'm writing this I'd like to point out that I really like the way Waves TDM GTR sounds, although not a fan of the majority of Waves' products that I've bought. I also own an 11R, but TDM GTR would still be my go to guitar pre when amp, cab and mic are not available. Perhaps the 64-bit Eleven MkII AAX has been progressed to something better. But this again comes from a post guy that sometimes meddles with music.

[innerbooty]

Just to clarify, in the above post, did you mean to write "AAX", or is "AAE" some fancy new algorithm I'm not even aware of...?

I think the sense of urgency has mellowed out for me a bit since I discovered how nicely Altiverb seems to run in RTAS. I figure if I can get a couple of them going in a session, I'm pretty good. I have a relatively small operation here, and the mixing I do isn't generally hundreds of tracks.

I really do like the idea of a Hackintosh, but I continue to be intrigued by the idea of Native, which is "relatively" affordable. Love the idea of so much ADC. And a better sounding mix engine. But still pained by the idea of possibly having to jump through hoops when going between mixing and tracking mode.

But I was just listening back last night to some albums I did on my old MIX system. They sound really good. I was very careful to leave faders at zero whenever possible, leave adequate headroom, make sure I had similar plugs on tracks doing parallel processing, good converters, etc. So there is absolutely no reason I can't work this "new" HD system for another 5 years or more. It's just the somewhat irrational itch to upgrade...

Interesting that you are using a separate HD system for reverbs, since this is exactly what a buddy of mine suggested when I mentioned my current Altiverb issues to him. He is also a film guy, coincidentally. He said forget the expansion chassis, just buy another HD rig with a digital I/O to use for 'verbs.

But I think the Hackintosh is the best bet to expand my current rig. Just need to find the time, patience and fortitude to tackle the project...

[antonis]

AAE as Avid Audio Engine

[innerbooty]

Ah, ok. Got it...

[John_Toolbox]

Originally Posted by innerbooty

Interesting that you are using a separate HD system for reverbs, since this is exactly what a buddy of mine suggested when I mentioned my current Altiverb issues to him. He is also a film guy, coincidentally. He said forget the expansion chassis, just buy another HD rig with a digital I/O to use for 'verbs.

I sold my old mix system in 2009, and really started to miss some of the TDM plugins I had, so I built one just for this purpose. I don't use it as often as I thought I would, but I was really surprised at how useful it is when I need it. As an example, I did a project a while ago that required some heavy guitar. All of the modern amp sim stuff I used sounded good, but just didn't get the sound I remember getting 10 years ago with Amp Farm. So I ran everything through the old TDM rig and got exactly what I was looking for. This might just be because I spent a lot more time with Amp Farm back in the day, so I know it better... but that's what I love about having this, I know exactly what to do with it when I need something.

But I think the Hackintosh is the best bet to expand my current rig. Just need to find the time, patience and fortitude to tackle the project...

There is something to be said for having everything in a self contained rig. I've had several different setups over the years that involved anywhere from 2-5 computers. Not only does it add more time to setting up a project, it also makes it very difficult to recall an old project.