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HGST Ultrastar He8: Sample Variation
This page assesses sample variation using five brand-new samples.
Consumer hard drives tend to vary in speed by as much as 15%. Enterprise hard drives can be expected to perform at slightly loser peak transfer rates, but with more consistent performance and less sample-to-sample variation (for better RAID behavior).
In some cases, enterprise hard drives also tend to be the “cream of the crop”: consumer drives might in fact be the same build as enterprise drives, but did not make the “cut” for enterprise quality in some way. Whether this is true may vary by vendor and/or drive model.
Sample variation, 5 samples, peak transfer speed
DiskTester run-sequential used to test peak speed of empty drives, freshly erased. Throughput figures are real-world figures through the OS X file system.
Performance variation across the five samples is held to within 4% difference (range from 192 to 200 MB/sec = 4% variation). This is a tight spread; many consumer drives vary by as much as 10-15% between samples.
See also the peak performance vs transfer size page.