5400 RPM HDD (SATA III) vs SSD (SATA II)

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5400 RPM HDD (SATA III) vs SSD (SATA II)

I've got a late 2012 mac mini with a 1TB HDD in it. I'm thinking about adding an SSD to it. This lead me to debate a few configuration options, one of which I'd like to ask here. I'm not sure what RPM of the stock HDD in this mac mini is, but it feels like it's a 5400 RPM drive, so for this example, let's assume it is (unless someone tells me otherwise).

Assuming it has a stock 5400 RPM SATA III (6 gbps) HDD in it regardless of size, would there be any significant speed increase/benefit to installing a SATA II (3 gbps) SSD?

I'd have to assume that even though the SSD would be on SATA II, it'd have to be substantially faster performance-wise than a 5400RPM HDD on SATA III...would you agree/disagree?

iMac (27-inch, Late 2012), OS X Mountain Lion (10.8.2), 3.4GHz Intel Core i7, 16GB RAM

Posted on Sep 23, 2013 2:02 PM

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Answer 1

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Kappy

Level 10

361,741 points

Sep 23, 2013 2:07 PM in response to Zathrak

Why would you install a 3 Gb/s SSD when your model supports 6 Gb/s? However, in either case the SSD should be faster than the HDD whether it was a 5400 or 7200 PRM drive. You would know that if you took some time to research the statistics on your HDD and the SSD models you might use.

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Answer 2

tbirdvet

Level 6

13,635 points

Sep 23, 2013 3:38 PM in response to Zathrak

You are correct that the standard hard drive is 5400. I would use a 7200 Hybrid or a SATA III SSD. I have used both and either one shows a sunstantial speed bump. If cost is not an issue go with a 512GB SSD.

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Answer 3

Zathrak Author

Level 1

23 points

Sep 23, 2013 4:47 PM in response to Zathrak

My mistake - I should have also mentioned that I happen to have a SATA II SSD sitting around not doing anything and I was debating using it in place of the stock 5400 RPM drive. I have a moddest understanding of relative drive speeds but don't know enough about the real-life differences between SATA II and SATA III if like in this case the SSD was SATA II and the 5400 RPM HDD was SATA III. Again, I'd think that the SATA II SSD would be far superior in terms of speed and drive access due to the 5400 RPM drive speed (despite the SATA III interface) but I don't really *know* that. This is what I wanted to verify with others before going for it. Yes, a SATA III SSD would be ideal but I'm asking because I already have an available SATA II SSD just sitting around.

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Answer 4

tbirdvet

Level 6

13,635 points

Sep 23, 2013 4:52 PM in response to Zathrak

Then use your SATA II SSD. It will much faster than the 5400 HD.

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Answer 5

Kappy

Level 10

361,741 points

Sep 23, 2013 5:31 PM in response to Zathrak

Sorry that was unclear to me. You will obviously see a reduction in throughput between a SATA II and SATA III SSD. But despite that the SSD should be faster than most 5400 RPM HDDs. Some 7200 RPM drives connected to a good chip can do better than some SATA II SSDs, depending upon the particular model. R/W speeds of a good SATA II SSD can approach 250 MBs/s which is about half that of SATA III SSDs.

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