For some time, the move has seemed inevitable – even more so as the rumor mill started echoing with suggestions that a native release was coming. But now, it’s happened: Pro Tools HD will now run without HD DSP hardware. And that’s not all — you can also use the same hardware with your existing DAW of choice, for users of software like Cubase and Logic.

There’s a price tag attached, though. This remains what for many would be a high-end solution. At US$3495 retail and up, it’s not competition for buying a basic interface card and Cubase. Think, instead, a more affordable and flexible way to equip studio rigs, and some potentially serious competition for vendors like Apogee, especially since you can use any DAW you want.

Just to say that again: Avid is making a version of Pro Tools HD that runs on the CPU and supports any DAW on Windows 7 or Mac OS X Snow Leopard and higher.

The AIR (Avid) user blog has some terrific analysis on the announcement even before it became public, comparing leaked price info for Native to an Apogee rig. If you haven’t been reading the AIR blog, they’ve hardly been shills for Avid; they’ve savaged some of the company’s decisions. And they’re actually pretty positive here. (Spoiler: Avid winds up being cheaper than Apogee by a few hundred bucks in their calculus.)
Is An Avid Pro Tools HD Native Core System Expensive?

What you get for that investment, though, is something worth discussing. It also reveals what’s necessary to get real, low-latency audio operation, which is relevant even if you aren’t in the market for Pro Tools|HD Native. CDM gets some insight into that from the developers.

First, Pro Tools|HD Native at a glance. Bundles:

Native core: $3495 buys you the necessary PCIe native card plus Pro Tools HD 8.5 software. The card comes with two Digilink mini ports on it.

Native core + OMNI Add an HD OMNI interface to the above. Total: US$5995.

Native core + HD I/O 8x8x8 Get a full 8x8x8 HD I/O interface. Total cost: US$6995.

Native core + HD I/O 16×16 analog US$7995.

Availability: November 4.

So, why bother with “HD Native” when there are versions like LE? The difference is that some of the more serious studio features remain:

• Surround, VCA mixing
• Destructive/track punch, advanced automation
• Solo Bus AFL/PFL, track-based input monitoring
• Sync HD support
• 9-pin Machine Control
• Venue support. (Yeah, that’s pretty huge, since Venue rigs don’t necessarily need all the TDM stuff.

This isn’t a TDM solution, though, so you don’t get TDM plug-in support, which for many is one of the big draws of Pro Tools. That includes the recently-announced HEAT, an analog-modeling sonic sweetener based on the qualities of tape. (There’s more to say about HEAT; I just got off the phone with its talented designer Dave Hill, so expect the results of that interview soon.)

It is a significant “mid-range” studio solution, and will likely fill a big need for Pro Tools customers. Avid told CDM in a briefing yesterday that they’ve gotten enormous demand for just such a solution. Just doing a discounted upgrade to HD got a big response, and users have wanted something between LE and the TDM-based HD for project or secondary studios. It also seems to me that it demonstrates Avid is willing to change, which could have greater implications down the road.

What you get is, says Avid, not a replacement for their DSP solutions, but otherwise unrestricted in sync, I/O, and functionality. It has the mixing and I/O LE lacks, and it even supports legacy “blue” HD converters (192, etc.), making it a likely candidate for upgrading studio setups that didn’t make the leap to 8.5 software.

If you don’t want to use Pro Tools as your DAW, you get 64 channels of I/O with any Core Audio (Mac) or ASIO (PC) system. Avid says they’ve tested extensively with Logic and Nuendo; Digital Performer, SONAR, and others should work, too.

And, notably, it’s a native system with extraordinarily low latency. Pro Tools|HD does .44 ms (at 96k and a 64 sample — yes, sixty-four total – buffer). But HD Native does a very respectable 1.6 ms; less than half that if you choose direct monitoring while recording, which you can do with simple stereo monitoring or even 7.1 surround setups. That’s 1.6 ms through the native setup, through PCI, and through the kernel and operating system. We’ve heard those kinds of theoretical numbers, but it’s a big deal to get it consistently on a computer system with a single, stable setup.

The Latency Story

I was curious to hear more about how Pro Tools|HD Native achieves those low latencies. The answer says something about the direction of Pro Tools, but also the potential of native computers for this sort of processing in general, regardless of the tool you use. (And that’s the sort of information we like.)

Bobby Lombardi, head of Pro Tools Product Management, explains to CDM:

The magic answer to all this is the Core Audio/ASIO “safety buffer” which is an additional layer of latency used by third party IO manufacturers (HW) manufacturers who provide Core Audio drivers for their HW. We also use a safety buffer for all of our hardware (including LE and M-Audio) that have Core Audio and ASIO drivers.

A safety buffer can have a very wide range of values. PCIe based hardware IO is the best case where manufacturers could theoretically get down to a 9 sample buffer, and go as high as several hundred samples for USB devices.

The key for a high-performance, low-latency system is PCIe-based IO and quality low-latency converters. This is the main reason why a PCI-based Pro Tools HD Native system combined with an HD IO has such exceptional latency.

The story gets even better at 96kHz sample rates where most converter latencies where the host CPU latency halves itself, and many high-end converters are capable of a low-latency converter mode without sacrificing quality. Our new HD IO and OMNI IO have such converters and perform in a low-latency performance mode when used at 88.2 and higher sample rates.

So to recap. The best possible latency story for Pro Tools HD Native using AD/DA converters is:

Pro Tools HD Native
Pro Tools HD Software @ 96kHz, 64 sample playback buffer
HD IO or HD OMNI interfaces

If anyone wants to get deeper into these issues with Avid (or anyone else), let me know; I’m game.

Don’t Write Off TDM Yet

Worth saying: this is probably good news for the future of DSP-based, TDM Pro Tools systems, not bad. The business advantage for Avid is, they sell more hardware and software, and keep more people on their platform. (I don’t think they can be faulted for that.)

But if you’re wondering, why bother with the pricier TDM systems at all, the story there doesn’t really change. As Avid puts it, TDM’s advantages don’t suffer when your CPU becomes more powerful. That just means you can use all the horsepower of the CPU and all the additional DSP processing of the HD TDM iron. Some of their customers are also using pretty extreme use cases, like recording 500 channels a time of a symphony orchestra. (I got an angry note regarding Logic Pro after writing a review of Apple’s DAW for Macworld where someone complained that Logic was choking over just sort a setup. Naturally, as a home producer, I had neither tested – nor could really conceive – what that setup looked like.)

There’s also time. Developing highly-optimized TDM plug-ins in Assembler is a different game from writing RTAS (or VST, or AU, etc.) plug-ins in C, and not everyone will port from one to the other.

What’s interesting to me, though, is that some of these issues transcend usage scenarios, budget, and the like. I don’t doubt that every musician would love 1.5 ms latency. And those fundamental architectural issues I believe will continue to be relevant for the entire musical community – whether their tools count as particularly “Pro” or not.

On a purely technical level, how does Windows Vista work with a leading pro audio application? A lot of that depends on just how much the developer does to tune their software, and to hook into some of the new audio technologies in the OS.

I wanted to know more about how Cakewalk’s SONAR 8 DAW was specifically optimized for Windows Vista. SONAR 7 was already out in front with support for Vista’s audio plumbing, but SONAR 8 promises quite a bit more. With the help of CTO Noel Borthwick, we were able to go through internal engineering documents and communication and get the full story. (Noel, who has a resume as a Linux programmer as well as leading the top Windows audio developer’s technical efforts, has been very frank in the past about Vista, walking us through changes before launch and real world experiences one year later.)

As Noel puts it, this is “more minute detail than most sane people would care to read,” but that’s just the kind of detail we like. If you just want to know whether your software will work, this is overkill. But for those of you who, like us, are interested in why some things work, this is a good place to start. I also sincerely hope other developers on Windows will start to invest more time in some of these details.

If SONAR 8’s music features are what interest you, see our first look:

SONAR 8 Preview: Instrument Tracks, Beatscape Instrument, Transient Shaper, Enhanced Performance, Other Goodies

I’ll repeat my current recommendation on Windows. If you’ve got a system running XP and you’re happy, I’d stick with it. But I see no reason to avoid SP1, unless you have a specifically incompatible setup, now that SP1 and driver updates have brought some maturity to the platform. I find the new OS more usable and, with the right software and drivers, even more stable. (This is not what I would have said before SP1, especially early after launch.) In fact, this walk-through with Noel demonstrates why, in the case of a SONAR system, you might be happier under Vista, on a point by point basis. I’ll avoid the “versus Mac” or “versus Linux” arguments, as those tend to get more complex and abstract, but there’s some good stuff here for those of you with Windows experience.

And yes, if any developer would like to do a similar tour on the Mac or Linux, I’m all ears. But just in case you think I’m crazy when I say there is some really robust stuff for audio in Vista, now you’ll know just what I mean.

CDM Executive Summary

Okay, here’s the quick run-down.

SONAR 8 involves improved performance optimizations, even relative to previous versions of SONAR. As far as I know, this is unparalleled progress on the Windows platform; few, if any developers are doing this kind of work. That’s not to say you won’t get good performance out of other Windows apps under Vista – certainly, I spend a lot of time in hosts like Ableton Live, Kore, and FL Studio on Vista — just that SONAR is leading here. (Developers out there doing similar work, we’d love to hear from you; developers not doing this kind of work, I hope this can piqué your interest and/or point you in the right direction, and certainly I don’t think anyone on Windows is trying to protect “trade secrets” – the better this stuff works, the better for everyone.)

The upshot of all of this should mean:

• Reduced audio glitches and performance bottlenecks, thanks to improvements to the audio engine itself, as well as the way the software makes use of the kernel (which impacts drivers also using the kernel)
• Smoother peformance in the UI as you zoom, draw, and the like
• More efficient performance, through optimization at the driver level and by better supporting Vista’s new audio API and threading mechanisms
• Better support for both WDM (Windows Driver Model) and ASIO drivers, and better performance at lower latency (that’s always the measure – you can always reduce latency, the question is whether you can maintain reliable audio performance when you do so)
• x64 is now, effectively, ready for prime time latency-wise

Now, here’s Noel to say that in more technically precise terms.

Performance Optimizations

Although every version of SONAR we shipped in the past had some degree of optimization work, SONAR 8 is the first version of SONAR to which we applied the same engineering process to performance optimizations as we do with other more user visible features.

i.e. we established goals, built a specification for the optimizations, split up the work into milestones and tracked the progress of these tasks just as we do for other features. To make testing more deterministic, we devised various internal profiling tools in order to track and measure changes in performance across a variety of hardware platforms on XP as well as Vista.

Systems tested included brand new cutting edge platforms from Intel and AMD as well as earlier generation machines.

We split up this work into the following classes of performance enhancements for SONAR 8:

1. CPU and kernel level optimizations – use less of your CPU to do the same amount of work
2. User Interface optimizations – faster drawing, scrolling, zooming
3. Driver level optimizations – more efficient access to drivers, minimizing driver state transitions
4. Vista OS specific optimizations – Better use of MMCSS thread priorities, support for custom MMCSS task profiles, new WASAPI support
5. Audio engine optimizations – optimize "hotspots" in our bussing, streaming and mixing code

As a result of all these changes, SONAR 8 has the following benefits:

• greatly minimized kernel usage. This helps provide more "kernel bandwidth" to drivers who need it the most. More kernel bandwidth translates into less potential for audio glitches.
• Lower CPU usage – translates to better performance at low latency
• More efficient use of audio drivers – esp with ASIO drivers
• Better performance on Windows Vista esp X64 [64-bit Windows]. Many of the complaints of Vista performance as compared to XP have been solved with SONAR 8. X64 low latency performance should now be on par with X86.
• Faster application launch
• Less flicker in GUI. Track view splitters no longer flicker when resizing.
• More responsive zoom and scroll with large projects. Zooming with wave files now uses 1/2 the RAM with 24-bit or less stereo or mono files used.
• Better meter performance.
• Improved thread scheduling by insuring threads are properly distributed on processors.

Benchmark: Overall benefits of SONAR 8 as compared to SONAR 7

CDM: Will we see these improvements in Project5? What about your instruments, like Rapture and Dimension, running as apps (instead of inside another host)?

Noel: We don’t have any firm plans for P5 at this time. Our “minihosts” for instruments don’t have these enhancements. It’s less relevant since these are far simpler with just a single instrument.

Windows Vista – New WASAPI driver mode

WASAPI (Windows Audio Session API) is the new multimedia API to talk to audio devices in Windows Vista. It represents the first real general purpose audio API from Microsoft in over 15 years, since MME from Windows 3.1.

The primary advantages of WASAPI are:

• Supports a wide variety of audio devices (any device that has a WDM driver should work in WASAPI mode if Windows can use it in exclusive/event mode)
• Provides low latency access to the device in WASAPI exclusive mode. (unlike older Microsoft API’s like MME or DirectSound)
• Model that is the closest to the low level WDM kernel streaming approach, while yet providing a higher level of abstraction for the device.
• Primary audio API for next generation of Windows.

Windows Vista: WaveRT

In WDM mode WaveRT is automatically used internally when SONAR detects a WaveRT capable WDM driver. A [WaveRT] suffix is added to the driver name in this case.

In SONAR 6.2 we first introduced support for Vista-specific WaveRT. Direct WaveRT mode is available in SONAR when you are using WDM as a driver mode and a WaveRT capable device is detected. In Vista SP1, Microsoft made some fundamental changes to WaveRT API’s that return the device sample position,
returning a cyclic position rather than a monotonically increasing position. In SONAR 8 WaveRT support has been updated and enhanced so that it works properly with Vista SP1.

CDM: You talk about using a WaveRT driver. Do you have to do anything to switch to WaveRT?

Noel: You don’t switch to WaveRT. In WDM [Windows Driver Model] mode, there is no choice – if a driver exposes itself as WaveRT, that’s the only mode of communicating with it. The same applies in WASAPI except the difference is that WASAPI itself communicates with the driver in WaveRT mode internally.

CDM: I have to admit, I’m used to working with ASIO. How do I know if a device has a WDM driver?

Noel: Any audio interface that works in Windows itself (i.e. if it shows up as a device in control panel -> sounds and audio devices) HAS to have a WDM driver. Otherwise Windows will not recognise it.

I don’t know of any interface that provides ONLY an ASIO driver. Some provide minimal WDM drivers that aren’t tested very well.

Windows Vista: MMCSS task profile support

The Multimedia Class Scheduler Service (MMCSS) provides Windows multimedia programs, including SONAR, with prioritized access to CPU resources for time-sensitive processing.

By default, SONAR uses the MMCSS task profile named Pro Audio. If desired, you can now instruct SONAR to use a custom user created MMCSS task profile.

CDM: Under what circumstances would you switch task profiles? What profile other than Pro Audio would you want to use?

Noel: You can tweak the MMCSS thread settings via a custom profile. I have a profile I tweaked that works marginally better than Pro Audio. It’s pretty technical stuff – You will have to read this link to get the details.

http://msdn.microsoft.com/en-us/library/ms684247(VS.85).aspx

Ed.: That’s a very technical explanation of a very technical topic; for more resources –

Mark Russinovich tours the enhanced Vista kernel

MMCSS, the Cliff Notes-style version on Wikipedia

Mark Russinovich on the interaction of MMCSS and networking

Interesting thread on the Cakewalk forum

More Information

You’ll want to see, previously…

Overview of Vista

Adieu, XP; How Vista SP1 is Doing, and Why This OS Generation Has Been So Tough

Vista for Audio, 1 Year Later: Talking OS Plumbing with Cakewalk’s CTO

Vista for Music + Pro Audio: Exclusive Under the Hood with Cakewalk’s CTO

Windows Sound Glitches Explained, Plus Glitches and the Fight-or-Flight Response

Compatibility

Cakewalk Vista Musicians’ Resource Page, Lots of Vista Drivers

Digidesign Talks Latest Windows, Mac Releases, Compatibility, Drivers

M-Audio Responds: Update on Driver Situation, New Drivers

Helpful utilities

12 Free and Cheap Must-Have Music Utilities for Windows

10 Free Non-Musical Windows Software Every Musician Should Use