How bad are these stats?

[jranaudo]

I ran HDTune and compared my two hard drives. My Western Digital WD15EARS is much slower than the seagate. Can anyone suggest whats going on? My WD is partioned so not sure if this is the problem or not.

Here is a link to the HDTune screen shots:

HD Tune Screenshots

 

[fzabkar]

Here are direct links to your graphs (no ads, banners, etc):

http://public.bay.livefilestore.com/y1pJykct9uSx8SJEQGx8GzPw0uwIabD73BJvP3e4nHHbITGf1yCAuxotxb2rFz0arkIpXOvNpo4u0dQvZUdE1liyw/STS_read.png?psid=1

http://public.bay.livefilestore.com/y1p2Vmfr8ByOVqR_8CAylJGnNGtcO_KPGKMKAchyCvCHWianJLLFbOetposBMDlhTOHMkSCZ0F4BSSjGTNiSoCJGg/WDEARS_read.png?psid=1

The maximum sustained data transfer rates for the Seagate and WD drives are 134 MB/s and 101 MB/s, respectively. The Seagate drive has 2 platters of 500GB each, whereas the WD has 3 platters of 500GB each. However, while the drives have the same data density, the Seagate spins at 7200 RPM whereas the WD Green drive spins at 5400 RPM.

Therefore the transfer rate of the WD drive, when compared with the Seagate, is ...

134 x 5400 / 7200 = 100.5 MB/s

So the difference is purely due to rotational speed.

BTW, you can infer the speed from the access time graph. The spread of data points is equal to the latency of one complete revolution.

The Seagate graph is about 8msec wide, whereas the WD's is around 11msec. These figures represent the time required for one complete revolution at 7200 RPM and 5400 RPM, respectively.

 

[jranaudo]

I had started suspecting the drives were 5400 RPM. WD calls it Intellipower but on their site they do not list anywhere (that I could find) the RPM of the drive.

Thank you for your explanation. It was very helpful in me understanding HD's.

 

[jranaudo]

Best answer selected by jranaudo.