[iMac] i7 iMac USB Performance

Andrew Lynch drew at atlynch.com
Wed Apr 21 22:54:06 PDT 2010

Hi Folks,
  New to this mac list, just upgraded from a Dual 2.7G5 to a i7 iMac with 8Gb ram.  I am struggling with the limited firewire connectivity as compared to my old mac.  I always had a pair of internal drives, an external time machine drive, and an external aperture vault.  They were a mix of firewire 400, firewire 800, and internal SATA.

So, I start playing around with connectivity on the iMac.  I have only one FW 800 port, so I want to use it to store the video I am editing.  So I move my general purpose scratch drive and my Time Machine drive to USB.  

I started to notice a huge variation in throughput when using USB.  If you number the USB ports on the back from 1-4 (looking at the back), connecting the hard drive to either port 1 or 3 gives be 32MB/sec throughput.  Connecting to ports 2 or 4 gives me 16MB/sec. If I connect one drive to port 1, and anything else to port 3, the throughput drops to 25MB/sec.  Using a HUB further degrades performance.

What I have decided to do is connect my Scratch drive on which I want decent performance to port 1, and my time machine drive to port 2.  I connect nothing to port 3, and a hub with my printers, etc to port 4.  This way I get one USB drive with decent performance, and Time Machine with crummy performance (12MB/sec), but that does not matter so much.

Any better suggestions?  I'd really love to stay above the 30MB/sec level for all my drives.


PS Has anyone tried and liked any of the anti glare options for the 27" imac?

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