All Macs In-Depth Tests
Performance Comparison Between a Fragmented and Unfragmented Disk

| Software Index | Previous Results |

The graphs below represent a performance comparison between a badly fragmented disk and the same disk optimized. Testing was done on a 500MB partition on a 9500/200 with OS 8.1 installed. Virtual Memory was set to 1MB over installed RAM.

Drive before optimization:

Allocation of free space

Allocation of files

Allocation of free space and files after optimization with Speed Disk

The Results:

These results are stopwatch tests and represent the performance difference in percentage of time taken to carry out a given task. Shorter bars equals better performance.






For the test below a folder totalling 65MB in size and containing 1,000 files were duplicated


For the test below a folder totalling 65MB in size and containing 1,000 files was deleted from the trash


The tests results below are from the benchmark program Speedometer 4.0. Longer bars equal better performance

Note: Optimization appears from these results to give you a modest performance gain . We used a 500MB partition for our test and it might be the case that the performance improvement would be greater on a lager sized drive that was badly fragmented.Unexplained is the poor performance of the optimized drive compared to the fragmented drive when copying the test folder. Aside from performance there are other good reasons to keep a tidy drive. MacSpeedZone welcomes your comments on these results.


The logical reason a duplicate might be faster on a fragmented drive is that the System wouldn't have to always go to the end of the drive to write the new data. In many cases, particularly with smaller files, it would find an open area on the disk nearby, avoiding the slow process of moving the head back and forth from one end of the platter (read) to the other (write) on the disk platter. Faster drives would make this less significant, and depending on how full the drive is, the difference in distance would change too.

Bill Patterson


External Links

  • MacTips tackles fragmentation in an informative article (tip #32)
  • Symantec - makers of Norton Utilities which contains Speed Disk a disk optimization program
  • Alsoft - makers of DiskExpress Pro a disk optimization program