Really stupid storage questions

I have been thinking about buying a Thinkpad T450S but I am confused about something very basic. There is a bay for HDD or SSD's of various capacities. There is the Micro HD 16GB M.2 drive. What is that drive for? Simply caching? Is the OS and applications on the main drive?

Now there is another M.2 SSD slot in addition to the first two, and most of my questions concern this third slot.

1. How large (capacity) SSD can go into that slot?
2. Can the laptop be configured with that drive as the boot drive and one put all the OS and applications on that drive and configure the primary drive as a pure storage drive that is never accessed by the OS except as a storage drive; i.e., no exe files on the drive that was intended to be the primary drive at all?
3. I hope I am making myself clear. If this cannot be done, can one configure, say, a 250GB SSD drive in the main bay (normal) and have a purely storage drive in a dock? This is probably the business solution but since I am simply a retired individual I would prefer to get the speed of an SSD as well as the cheaper storage of a 7200 HDD all in the laptop itself.

I don't even know what an M.2 SATA drive is or if it can be made the primary drive in a laptop.

 

1. M2 drives are one of 3 standardized lengths, and their capacity is limited by how long they are (based on how much NAND physically fits). Lenovo thus far likes to allow room for only the shortest size: 42mm. This means that each M2 slot will take up to a maximum 256GB SSD.

2. While Lenovo won't pre-configure it that way, you can certainly set an M2 SSD as a boot drive, and use the included hard drive for file storage. Most SSDs come with data migration software to make the process of transferring your existing operating system from the hard drive to the SSD easier.

3. You can also replace the hard drive in the main bay with an SSD and use an external hard drive for storage.

M2 is just a type of form factor which allows an SSD to connect to a specific type of PCI Express port, which allows the possibility of faster speeds.

 

I have this setup on my Dell, though using a different mSATA SSD, and 1TB hard drive, and on my X220. It's really the way to go and this will work on the T450s.

 

Thank you both. So Lenovo won't preconfigure it that way? Will they permit the substitution of a 250GB SSD drive for the 16GB "caching" drive? I mean will they do it? I better ask them.

 

It's unlikely they would.