Use SSD if you have it already. I have 2 512 SSDs and all the major programs and games are in those drives. Besides these two SSDs, I have one 2 TB SSHD. It is a hybrid and is a lot faster than normal HDD but a bit slower than SSD.

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It will reduce your loading, waiting and initialization time to almost 0 sec. Heck! My windows 10 and Autocad 2017 for rendering loads at max of 1.2 sec. I recorded that