I have a Lenovo IdeaPad Z575 laptop and I've just bought an adapter that replaces my DVD drive with a port for an SSD/HD (one of these things). I already had a HD inside my laptop and I've just bought a new SSD. I plan to migrate my OS to the SSD and keep the HD for files and similar. I'm curious which drive should I put inside the caddy adapter and which one should I put inside my laptop? How will the speed be affected (if it will be affected)? Are there any other potential problems I might run into?
Such HDD caddys are often only SATA2/3GBit/s and would slow down the SSD because it limits the speed to 250MB/s.
I have a similar configuration and added the SSD to the native HDD slot and the old HDD into the caddy (it looks like I use the same for in my Dell laptop).
There is no difference, as both are SATA ports running off the same controller.
I would put the SSD with the OS in the laptop and the data drive in the caddy. This will allow you to reattach the DVD drive if necessary. If the drives were swapped, you couldnt do this.