On August 28, barefeats.com posted some performance numbers comparing the PowerMac G5 Quad to the Intel-based Mac Pro on a new “Retouch Artists” Photoshop benchmark.
Barefeats.com obtained a PowerMac G5 Quad timing (54 seconds, then 36 seconds in a revision) that is vastly different than mine. I’m not saying their figure is wrong—but it is completely different from my result, and there must be an explanation. My results were as follows:
run #1: 166 seconds, processor performance = auto
run #2: 165 seconds, processor performance = auto
run #3: 162 seconds, processor performance = high
run #4: 163 seconds, processor performance= high
PowerMac G5 Quad, 8GB RAM, 4-way striped RAID, CS2 history = 20, CS2 Cache Levels = 6, CS2 memory usage = 100% (3072MB), dual monitors, nVIDIA GeForce 6600 with 256MB memory. No other applications running except Activity Monitor. Time measured is clock (real) time.
I’m hoping barefeats.com is right and my copy of Photoshop will double in speed by reinstalling it! (I’m half serious, given the scrolling problems I’ve had with Photoshop). More than likely, the numbers reflect some Photoshop CS2 configuration. My feeling is that running a benchmark with artificial settings is silly, so I’ve stuck to the settings I normally use in everyday work.
Before we delve into details, let me state some principles to be borne in mind when reading benchmark results:
First caveat: always mistrust new, unproven benchmarks. Good benchmarks are extremely difficult to write. I know—I wrote benchmarks as a professional software developer for a time.
Second caveat: Take performance claims with a grain of salt until you see a consensus emerge.
Third caveat: Configuration and preferences can affect timings considerably.
Fourth caveat: Validate the results by testing yourself, if possible.
I trust barefeats.com, and I regularly correspond with Rob-Art, the site author. I’m working with him to determine why our results are so different.On the Quad, CPU utilization was extremely poor in this test, using only about 1/3 of the available CPU power (130% out of 400% max). Take a look for yourself (click for larger version):
How did the MacBook Pro fare? Well, 2GB of RAM is simply not enough for serious Photoshop work. The test was running efficiently until Photoshop hit 1.8GB of real memory (out of 2GB available) in the Gaussian Blur step, whereupon massive paging (swapping data from memory to disk) slowed the MacBook Pro numbers to a crawl. Time: 380 seconds—and that doesn’t count another 20-30 seconds of paging just to quit Photoshop. Were it possible to install more than 2GB of memory in the MacBook Pro, it might make a perfectly good desktop replacement even for beefy tasks. But it is crippled by the 2GB limit for such things.