Issues with installing SSD instead of DVD drive?

It is common to replace a MacBook Pro's hard disk drive (HDD) with an solid state drive (SSD), however, that may pose a threat to the HDD if installed in the optical bay instead of the SuperDrive.*

Therefore, that leaves the option of:

• Leaving the existing HDD where it is.
• Then installing the SSD instead of the optical drive (SuperDrive) with a bracket.
• While still using the SSD as the main boot drive.

Some websites mention that there may be issues with sleep and hibernation if this is done.

Is that true? Can it be mitigated?

Are there other issues with this approach?

_{* It could also mean that the HDD will be louder, since the main bay where it is usually housed has rubber to muffle vibration noises.}

I usually place the lighter drive in the optical bay since it's not as securely connected to the body as the intended HDD slot. This also plays into the rubber shock mounts for the HDD which both protect it from accelerations as well as isolating/dampening whatever vibration the drive motors cause.

As phrased, you may get a null answer since there may not be any issues with either placement. Macs can boot from external drives and have no problems writing the sleep image to an external USB or Thunderbolt drive since the OS wants to keep the system on one drive.

The only issues I've seen are people using links to place some of the core OS and support files on a secondary drive rather than just placing user files (home folders) and safer documents on a manual/fixed tiered storage system.

With core storage and Apple's broad support of any SSD to comprise a FusionDrive the need to micromanage what files live on which tier of storage might hopefully become a thing of the past.

Some Macbook Pros don’t have full SATA III in the optical drive bay so I opted to put my samsung 840 pro into the main bay to take full advantage of the speed.

On your mac, open up “system information” (applications/utilities/system information). Find "SATA/SATA Express” in the side bar. Click on the SATA Connection and see under “negotiated Link Speed” for your optical drive.

There is a slight hiss from having the HD in the optical bay, but it’s barely noticeable and it’s a WD Black 7200 rpm.

There are issues with hibernation but I just turned it off since I turn off my computer if I’m going anywhere far and boot times with an SSD are ridiculously fast.