Here at CDM headquarters in sweltering NYC, I’m pretty excited about future Intel Macs, and in the meantime I’m happy with Apple’s current lineup for music. But music apps and plug-ins that don’t get ported to Intel-compatible form probably won’t run at all.

You may havce heard that your existing apps will run on Apple’s new hardware when it begins shipping next year, thanks to emulation software called Rosetta. Think again. Here’s the scoop:

Rosetta will be slow. Rosetta’s own developer claims only 60-80% performance for computationally-intense apps (read: audio). Analysts peg the numbers as low as 30-40%. And that doesn’t include lost performance by the absence of the G4/G5 and Velocity Engine, which can boost audio performance. Not to mention, anything less than 100% performance is basically useless to audio users. (This also explains dismally-low benchmarks that have been making the rounds on the Web. It’s not the Intel chip that’s slow; it’s Rosetta.)

Rosetta will break your music app anyway. You’re not likely to even find out how slow Rosetta is running music and audio apps. See Appendix A in Apple’s tech documentation (PDF link) for the new universal binaries. Rosetta won’t run apps that make use of the AltiVec (Velocity Engine), apps that require the G4 or G5, or apps that either rely on (or are) kernel extensions. As far as I know, that pretty much rules out ALL Mac audio apps. (Several readers have pointed some of these caveats out; thanks!)

ALL your plug-ins will have to be ported. It gets worse. If you have even a single plug-in that has PowerPC code but not Intel code, the entire host application will switch over to Rosetta. See above for what happens to music apps when that happens.

So, is this the end of the world? No, absolutely not. Developers are saying that porting their code is not going to be a big deal, and we have at least a year to wait — maybe more, if Apple in fact ships PowerPC machines through the end of 2007 as it’s currently indicating. If anything, this suggests why waiting to buy new hardware is silly for most users. Use the stuff that works today. When it’s Christmas 2006 and you just absolutely have to have some ultra-speedy new Intel-based Mac, with that fancy new chip that isn’t available now for either Mac or PC, you’ll upgrade your software. All of it. And this is an excellent reason to avoid companies that aren’t keeping pace with new hardware and OS releases. I’m not naming any names, developers — so make sure this isn’t you.

Sources / additional reading:
CNET on Rosetta
Macworld’s Jason Snell on what you need to know about Intel and Mac
Apple on the new universal binaries with PPC and Intel compatibility in one app, including documentation on Rosetta