Hands on with the Mac Pro: Putting it to work Page 2 of 3

Audio, video, and virtualization tasks put to the test

by Rob Griffiths, Macworld.com

Audio and video

Unlike the mini, whose primary role in many households may be that of A/V center, it’s not likely that many of us will purchase a Mac Pro to stick next to our televisions. That doesn’t mean that it’s not a great audio-video machine, of course; it’s more a comment on the machine’s bulk and noise level. There’s enough horsepower here to handle just about any audio or video task you throw at the machine. As such, I’ll just give a few highlights about the Mac Pro's performance in this area.

Audio: I was interested in seeing how well the new machine would rip a CD. So I grabbed one at random from our collection (Mark Knopfler and Emmylou Harris’ All the Roadrunning ). To get a baseline, I first ripped it on the Dual 2GHz G5. My import settings are to rip to 192Kbps MP3 with VBR enabled on High. On the G5, the import took a little more than four minutes—4:03 to be exact. Moving over to the Mac Pro, I first used the stock Sony drive, and the import took just 2:28 (and yes, I made sure the import settings were identical). I then deleted the imported songs and tried again with my after-market drive, which reads CDs at 48x versus the stock drive’s 32x. Total import time: 2:01. The extra rotational speed snipped almost 30 seconds off the import time.

Next, I was curious about the speed of the CPUs themselves, without the need to use the optical drives. I copied the AIFF for the track “All the Roadrunning” to the hard drive (it’s about 41MB), imported it into iTunes, and then used the Advanced -> Convert Selection menu item to convert the track to different formats. On the Dual G5, converting to 192Kbps high VBR MP3 took about 9 seconds; converting to 192Kbps AAC took a little more than 12 seconds. On the Mac Pro, those times dropped to 3 and 7 seconds, respectively. Clearly the four CPUs have a lot of power.

HD Video: There are no issues with HD playback—the Mac Pro handled everything I threw at it without complaint. The CPUs weren’t even breathing hard during playback. So I thought I’d tempt fate again, as I did with the Mac mini, and try playing two HD clips at once. On the Mac mini, QuickTime died a painful death when I tried this, exiting abruptly. So what happened on the Mac Pro? Not much at all—it just worked. It worked so well that I threw another curve at it—I asked Snapz Pro to capture the 1,440-by-900 window, with sound, at 30fps while the two HD clips were playing back. Amazingly, the machine still had no troubles at all. Here’s a brief snippet of the video, at two reduced sizes—click the link to open the video of your choice in a new browser window:

720x450, 1.6MB     360x225, 840KB

As you can see, the machine performed admirably, with nary a hiccup. In fact, if you look at the four vertical bars on the right side of the menu bar, you can see that the CPUs weren’t even maxed out for most of the time. My G5 will try to play two HD clips at once, but it won’t do so very well—there’s lots of stuttering audio and dropped video frames.

Since two clips didn’t seem to cause any issues, I upped the ante—three HD clips at once. No problem. What about four? While I still didn’t kill QuickTime, this did at least force the CPUs close to maximum utilization. As evidence, check out this large screenshot (148KB, 1440x900). Four clips playing, still no dropped frames or audio, but the CPU meters in the menubar are close to full. I could have continued the insanity, of course, and eventually found the spot that broke the machine. But suffice it to say that the Mac Pro’s ability to handle HD video is not something you need to question.

DVD Playback: There’s not much to say here, other than DVD playback worked fine. About all I tested was whether my new drive would work with DVD Player. It did—insert a DVD into either drive, and DVD Player launches and starts playing the movie. Unfortunately, you can’t play back two DVDs at once (not using Apple’s DVD Player, anyway).

Video encoding: In the original report on the mini, I tested video encoding by converting Bruce Springsteen’s “Devils & Dust” music video. This clip is 61MB in size, runs 5:15 in length, and was encoded with the Sorenson 3 codec. I set up QuickTime Pro to convert it to H.264 video at medium quality using the faster single-pass encoding method.

On the mini, the conversion took 14:39. On the Dual G5, the job was done in a little more than 7 minutes. On the Mac Pro, it took only a very brief 3:35.

As a further test, I installed HandBrake on the Mac Pro, and then set it up to rip my DVD of Charlie and the Chocolate Factory (well, to rip the main movie, not all the associated extras). I left all of HandBrake’s settings at their defaults, except I changed the Quality section to “Constant quality,” and upped the associated slider to 70 percent. I then started the rip and let it progress for five minutes. I repeated the exact same experiment on the MacBook and the Dual G5—and on my 12-inch PowerBook G4/1.25GHz, just to see how far we’ve come with the portables. Here’s how things came out:

Not surprisingly, the Mac Pro bested the other two, and by a substantial margin. What was surprising to me was how well the MacBook did against the G5. While the CPU speeds and counts are identical, the MacBook will take fully 16 minutes less to rip this DVD than will the G5. That’s impressive performance from a machine that cost less than half as much as the G5!

It’s also fairly obvious that the G4 chip in my PowerBook has been completely outclassed—the MacBook could theoretically rip almost seven DVDs in the time required for the PowerBook to process but one. Even if the PowerBook G4 had two CPUs, it wouldn’t be doing much better than 20fps, still well off the pace of the MacBook. To me, this clearly demonstrates one of the main reasons Apple gave for switching to Intel chips—there was much more processing power available for the laptop line.

If you’re working with video conversion, where time is money, investing in the Mac Pro seems like a very simple expense to justify.

Three takeaway points

The Mac Pro makes short work of ripping CDs into iTunes, and converting existing tracks between formats.

HD video playback doesn’t pose much of a challenge for the Mac Pro. Playing back multiple HD clips at once didn’t cause any issues, even when I was recording that playback at the same time.

The four CPU cores in the Mac Pro greatly speed the process of converting video from one format to another.

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