Photoshop scratch disk

[barry685]

I am building a new pc. The OS drive is a Samsing Pro 950 512gb m.2. I also have a Samsung 256gb 850 pro and an extra Ocz Vertex 2 90gb that I don't necessarily need. The OS drive will have at least 1/2 of its capacity free. Which drive should be used for the scratch disk?
Thanks

[JaapD]

You are best off to use the FASTEST disk as scratch disk, in this case the 950 Pro m.2. In the old days with hard drive platters it was better to use a separate disk because the head could not serve two purposes at the same time. With SSDs this is from the past, no need to have separate disks anymore.

[barry685]

Thanks