Optical Drives and SATA (and PATA) Saturation

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***Please let me know if you feel that there is anything I have overlooked, missed, or gotten wrong. I'm new to all this and just wanted to share some work I'd done with the community in hopes of helping out and giving a little back.

"TL; DR" after this paragraph and at end of post.

Hey all. I was digging around online, trying to find an answer to a question I had about whether a SATA disk drive I was looking to buy was SATA I, II, or III (1.5Gb/s, 3.0 Gb/s, or 6.0 Gb/s, respectively). No drives I looked at specified what version they were or what their data transfer rate was, and I could not find any queries or discussions (at least not with adequate answers) on the subject, so I did some math and figured I'd post my findings here, in case any others have the same confusion I had. After all, this is where I find a great deal of the answers to my hardware questions!

TL; DR:
The question is specifically, "What SATA version is this-that-or-the-other optical drive? And does it really matter (i.e.: should I make sure I have enough SATA II/III connectors on my motherboard to support a high-quality disk drive)?"

The answer to the first part of the question I am less clear on, but I know that for all intents and purposes, it boils down to this: All SATA optical drives are SATA I (1.5 Gb/s), or at least function below that threshold.

Here's the proof:

A CD, DVD, or Blu-Ray disc drive's data transfer speed will be limited by the read or write speed (depending on what the drive is doing) of the disc or drive (depending on which is lower). Drives can, of course, often write to a disk at any of a number of user-selected speeds.

So what are these speeds? Read and write speed can often vary within a given drive, and can be dependent on the type of disc in use (BD-R tends to be written to faster than BD-RE, for example). At the time of writing, Newegg.ca (Goh, Canada!) had no CD drive with a read or write speed higher than 48X, no DVD drive higher than 24X, and no Blu-Ray drive higher than 15X (though this is likely the technology where we can expect to see the most growth in the coming years).

But what do these speeds mean, exactly? The convention is based on the 1X speed, which is the initial market-entry read/write speed for each technology. For CDs, 1X is 0.153625 MB/s (or 153.625 KB/s). For DVDs, 1X is 1.385 MB/s. And for Blu-Ray discs, 1X is 4.5 MB/s. Any speeds above 1X are multiples of that initial speed rating, so 8X is 8 times faster than 1X (and twice as fast as 4X). You can see, though, that 4X on a CD is not the same as 4X on a DVD or Blu-Ray.

So now we can do the math to figure out the max data transfer rates of the various disc drives on Newegg. All we have to do is multiply the 1X speed (which is identical for the read and write functions) of each technology by the maximum speed found for any disc drives of that type (48X for CDs, 24X for DVDs, 15X for Blu-Rays)

For CDs (where 1X = 0.153625 MB/s): 48X = 7.374 MB/s

For DVDs (where 1X = 1.385 MB/s): 24X = 33.24 MB/s

For Blu-Rays (where 1X = 4.5 MB/s): 15X = 67.5 MB/s

When we consider the three versions of SATA (divide max data transfer rate by 1X speed of each technology and round down), we find that:

SATA I (150 MB/s) supports up to X976 CDs, X108 DVDs, X33 Blu-Rays
SATA II (300 MB/s) supports up to X1952 CDs, X216 DVDs, X66 Blu-Rays
SATA III (600 MB/s) supports up to X3905 CDs, X433 DVDs, X133 Blu-Rays

Wow.

So SATA I, with its lowly 150 MB/s data transfer rate can support even the fastest optical drive speeds out there. And then some. So you do not need to worry about whether your motherboard's SATA connection(s) will support your disc drive(s); they will.

What about PATA, though? Sure it's an older technology, but that doesn't mean it's gone! PATA came in speeds of 16, 33, 66, 100, and 133 MB/s. So:

PATA 16: supports up to X104 CDs, X11 DVDs, X3 Blu-Rays
PATA 33: supports up to X214 CDs, X23 DVDs, X7 Blu-Rays
PATA 66: supports up to X429 CDs, X47 DVDs, X14 Blu-Rays
PATA 100: supports up to X650 CDs, X72 DVDs, X22 Blu-Rays
PATA 133: supports up to X865 CDs, X96 DVDs, X29 Blu-Rays

So really, unless you're running a motherboard that's over 10 years old, you haven't got much to worry about as far as data transfer rates to your disc drive(s) are concerned.

TL; DR:
SATA disc drives, if they are version specific at all, are SATA I, but do not use its full bandwidth. Therefore, no, it does not matter what kind of SATA cable you use to connect it to your motherboard, since SATA is forwards and backwards compatible. That said, don't use a SATA II or III port (not cable, but PORT; the cables are actually electrically identical) if you've got a spare SATA I. Anything higher is a waste of bandwidth. As for PATA, chances are you're fine. Any PATA port from the last 10 years can support the speeds of any (or at least the vast majority) of today's disc drives.
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