4 DIMM slots, two of them are filled with 2x8gb sticks, the other two slots are accessible easily.
2 Hard Drive Bays - One for SSD, one for HDD.
If yours doesn't have an SSD in it, you can buy your own 2.5" SSD and fit it in easily with the extra Caddy that comes in your box.
SSD as your primary is 100% possible, and is in fact recommended. There are ALSO tools to help copy over your operating system (16gb USB needed) one of them being Asus BackTracker
For SSD's, many people like the Samsung Evo.
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