Negotiated link speed considerations for SSD choice?

Question

If my negotiated link speed is 3 GB (instead of 6 GB), does this still mean I'm using SATA III on my early 2011 Macbook Pro 17-inch laptop?

I ask because I'm currently upgrading my HDD with an SSD for this early 2011 Macbook Pro 17-inch model; does my negotiated link speed affect what kind of SSD's I should consider? For example, are there any SSD's that I would need to steer clear of?

Also, can someone explain the difference between installing the SSD in the main drive vs. the optical drive? What is the difference exactly and how can I take full advantage of it to maximize the performance of my early 2011 Macbook Pro? For example, if I put a Crucial M500 into the main drive bay, would updating the optical drive bay as well make absolutely any difference in my performance?

Here are a few links I considered (and a few others like it), but it did not help answer my specific questions: Is there a way to tell if I can use a SATA III SSD in my early 2011 MBP 15"? and What is an SSD drive's negotiated link speed?

Answer 1

I have done a similar thing with a 13 inch macbook pro 2012. I put a Samsung 840 EVO 120GB 2.5 inch Basic SATA Solid State Drive into the hdd bay and moved the hdd to the optical drive bay. Works great and much faster booting etc. From memory, I don't think it's an issue using a SATA III (6Gb/s) in a SATA II (3Gb/s) environment or vice versa, it's just that your speed will be limited by the lowest speed connection and that would basically mean that you are wasting money on a faster drive but getting a slower connection.

However there may be an issue with your connection - see this link

17 inch Mac Pro SATA issues

I don't think putting 2 ssd drives would make much difference as long as you put your OS on your fastest (ssd) drive with your Application folder. You can then put all your other files on you hd. There are various ways to set this up one way is discussed here

SSD and HDD setup in MBP

although there are other ways (google will produce other results).

I so seem to remember having trouble booting up from the optical drive bay though, so if memory serves correctly, I would suggest keeping the OS on the drive that you will be putting in the hdd bay (so presumably the ssd drive)

Answer 2

Think of it as the chain is only as strong as its weakest link.

Yes, there is. You need to look at the specs on the speed of each of your drives. Check in the About this Mac in your toolbar and go to more info, System report, the the sata section under Hardware.

In terms of the optical and main drive bay's, it doesn't matter which you use if both are capable of the same speeds. In most cases dealing with older models, the traditional hard drive bay provides the better speeds than the optical. I've read before that the optical bay will not always match the traditional bay.

I'd put my SSD in the main bay and your secondary drive in the optical. You can configure which drive to boot from within System Preferences if you choose otherwise.

I'd def put my OS and your applications on the fastest drive and use that to boot from. If you are using a regular hard drive to place in either of the bays then I'd also recommend you put all you media and other large less accessed files on that (especially if storage space is a concern or for some reason you are concerned about read/writes on your SSD).