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bojangles · Dec 9, 2011, 04:14 PM

Hey, all. I have three computers that I use regularly. Here are the specs:

1) MacBook Pro 13″ (2.7-GHz Core i7)
8GB RAM (DDR3 PC3-10600)
500GB, 5400-rpm SATA HDD (384GB free)
1.0-Gb ethernet
Mac OS X v.10.7.2
iTunes 10.5.1

2) Power Mac G5 (dual 2.0-GHz)
6GB RAM (PC3200)
two 500GB, 7200-rpm SATA HDDs in mirrored RAID (29.04GB free)
1.0-Gb ethernet
Mac OS X v.10.5.8
iTunes 10.5.1

3) Mac mini (1.42-GHz G4)
1 GB RAM (PC2700)
80GB, 5400-rpm PATA HDD (61.74GB free)
100-Mb ethernet
Mac OS X v.10.5.8
iTunes 10.5.1

Now, anyone can see that the G5 lies between the mini on the low end and the MBP on the high end. The problem is: I’ve noticed some slowness, especially in iTunes. Today, I decided to see if it’s just the G5 or if something else might be the culprit. I have a Synology DS211 gigabit NAS RAID for my media server, so I figured that would be a good test. All I did was Get Info on four identical tracks on each of the three machines and counted, using the computer clock, how long it took for the dialog to pop up. Here are the results:

MacBook Pro (connected via 802.11n): 3 sec, 2 sec, <1 sec, <1 sec
Mac mini (connected via 100Mb ethernet): 5 sec, 4 sec, 4 sec, 4 sec
Power Mac G5 (connected via 1Gb ethernet): 22 sec, 22 sec, 23 sec, 28 sec

The three machines have virtually identical iTunes Library files. As for the testing, I did the Get Infos on each track on all three machines, in random order, before moving on to the next track. I also checked ping times to the server; all three machines reported 0.0% packet loss, with the mini averaging 0.192 ms ping time, the G5 averaging 0.184 ms, and the MBP (which, again, is connected wirelessly) averaging 1.538 ms. (In other words, the G5 has the shortest average ping.) And yet, the G5’s Get Info times were 4-7 times as long as the humble Mac mini’s!

Anyone have any clue? Could it possibly be the internal RAID in the G5? (One would think that the 7200-rpm and SATA connection would make up for that.) I’m frankly at a loss here.

Thanks for any help you can give. I’d really like to get my computer back to running the way it should.

P · Dec 9, 2011, 07:12 PM

It's possible - although not very likely - that you are in some weird case where the working set exceeds the size of L2 cache in the G5 while fitting comfortably in the cache of the others. More likely that the G5 is looking somewhere else first before finding the file. What happens if you try to locate the file in the Finder (rightclick on the file)? Same time difference?