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I need some help in interpretting the following speed tests on two Volumes on my home PC.
The test:
- CrystalDiskMark 2.2
- Windows 7 Disk Cache was disabled
- Both volumes were 0% fragmented before the test
Drive C:
- A Windows 7 Software RAID1
Dual Samsung HD501LJ drives (500GB, 16MB Cache, 7200RPM)
Sequential Read: 69.580 MB/s Sequential Write: 10.434 MB/s Random Read 512KB: 36.241 MB/s Random Write 512KB: 11.191 MB/s Random Read 4KB: 0.499 MB/s Random Write 4KB: 0.283 MB/s Test Size: 100 MB
Drive D:
- An integrated Intel Matrix RAID 10
Four Seagate ST3500320AS drives (500GB, 32MB Cache, 7200RPM)
Sequential Read: 120.388 MB/s Sequential Write: 59.587 MB/s Random Read 512KB: 35.677 MB/s Random Write 512KB: 27.713 MB/s Random Read 4KB: 0.634 MB/s Random Write 4KB: 0.299 MB/s Test Size: 100 MB
Differences
Sequential Read: + 73%
Sequential Write: + 471%
Random Read 512KB: - 2%
Random Write 512KB: + 148%
Random Read 4KB: + 27%
Random Write 4KB: + 6%
Would you agree with these statements?
- "Sequential Read" improved probably because of: 4 disks to read from, not 2 AND better cache AND integrated RAID
- "Sequential Write" improved probably because of integrated RAID
- "Random Read 512KB" loss is nominal... and probably can't be easily explained in this scenario.
- "Random Write 512KB" improved probably because of integrated RAID
- "Random Read 4KB" improvement is a cross between Sequential Read (ideal) and Random Read 512KB (not ideal)
- "Random Write 4KB" improvement is a cross between Sequential Write (ideal) and Random Write 512KB (not ideal)
500gig drives are pretty close to the point where you do not want to use anything other than RAID10 (a stripe of mirrors) in order to be able to recover from drive failure. If you were using 1 terabyte dirves, I would say you definitely should not consider anything other than RAID10. On a home PC speed should be secondary to data security. – Michael Dillon – 2009-10-22T19:49:20.923
You wouldn't use Mirrors with TB drives? – None – 2009-10-22T20:03:41.080
As you have not specified either context or how these arrays are constructed no meaningful answer can be given. The various RAID different levels have pros and cons depending on how the array is used. e.g. Database vs simple file storage. There will also be a difference between using a proper hardware RAID controller or using Windows software RAID. – None – 2009-10-22T21:31:44.507
@John... thanks for your comment, but I am not asking which is better. I'm asking if somebody can help me understand the numbers that were generated by the CrystalDiskMark tool. I fully understand that how the configurations are used will help me make my decision. – None – 2009-10-22T21:34:40.850