Seagate 320GB Momentus 7200.3

The 320GB Seagate Momentus 7200.3 is a vastly better performer than the 2007 vintage 160GB Momentus 7200.2; it’s an inexpensive upgrade, well worth the money for the space and performance gains.

As of late 2008, Seagate Momentus 7200.3 offers the fastest sustained read and write speeds available in a 2.5" notebook hard drive (the Western Digital VelociRaptor won’t fit in most notebooks).

See the review of the Intel X25-M solid state drive for more performance data; this is one drive that performs very nicely on real-world tasks.

DiskTester results

Test mule: MacBook Pro (Oct 2008 unibody) 2.8GHz 
SATA hardware: internal SATA II connector
Driver: Apple standard
Drive model: ST9320421AS

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Sequential sustained transfer

These are excellent results for a laptop drive, exceeding the speeds seen only 18 months ago in 3.5" desktop drives. Peak performance is reached with a 512K transfer size, but 128K is very close.

# Sequential sustained transfer
----- Averages for "sg320" (512MB/start, 3 iterations) -----
Chunk Size    Write MB/sec    Read MB/sec
    32K           51.0            73.4   
    64K           64.7            86.9   
   128K           76.1            86.8   
   256K           82.8            87.3   
   512K           86.7            86.8   
    1MB           86.7            86.4   
    2MB           87.0            87.0   
    4MB           86.6            87.4   
    8MB           86.6            87.1   
   16MB           86.2            87.4   
   32MB           86.5            86.9 

Speed across the drive (area test)

These are class-leading results for a laptop drive in late 2008, exceeding the speeds seen only 18 months ago in 3.5" desktop drives. Results are shown for 1MB and 32MB transfer sizes.

---------------- Averages for "sg320" (512MB/1MB, 3 iterations) ----------------
Area (295.9GB)    Write MB/sec    Read MB/sec
       0%             86.2            86.9   
      10%             84.5            85.3   
      20%             82.3            81.9   
      30%             79.1            79.2   
      40%             77.4            76.1   
      50%             72.3            71.7   
      60%             68.1            67.0   
      70%             62.5            62.1   
      80%             59.4            59.0   
      90%             53.7            53.6   
     100%             45.0            44.7   
Average write speed across the volume: 70.0MB/sec
Average read speed across the volume: 69.8MB/sec
---------------- Averages for "sg320" (512MB/32MB, 3 iterations) ---------------
Area (295.9GB)    Write MB/sec    Read MB/sec
       0%             86.2            87.5   
      10%             85.0            85.2   
      20%             81.7            82.1   
      30%             78.7            79.5   
      40%             77.0            77.6   
      50%             72.2            71.2   
      60%             67.9            67.5   
      70%             62.6            61.8   
      80%             59.7            59.2   
      90%             53.6            53.5   
     100%             45.0            44.7   
Average write speed across the volume: 70.0MB/sec
Average read speed across the volume: 70.0MB/sec

Create and read files

This test times how long it takes to create and flush files to disk, and to read them back, with the Mac OS X cache bypassed so as to reflect actual hard drive performance. The test is run on empty freshly-formatted drive.

With the advent of “stutter” in mediocre solid state drives, it’s not a bad idea to look at the consistency of performance, easily visualized here.

Variance of 10MB file creation times (ms)