does it have dram cache?

There’s 1MB of DRAM cache for every 1TB of memoryEnter an answer to this question.

Does it come with windows installed?

Hello - it does not come with Windows installed. What I did was purchase this 1Tb module to replace the 256Gb module that came with my computer (which had Windows 10 OEM installed). I then used disk cloning software such as Acronis True Image to migrate my Windows 10 to the new SSD. The migration went very smoothly with no issues. I hope this helps.