What drive for bcache?

so i’m in the process of building myself a new server, well some is new and some is new to me. so far it consists of a rosewill RSV-L4500 case, 3x arctic p12 fans in the front, 2x arctic f8 silent fans in the rear, an ancient ocz modXstream 500w psu, and at the moment an equally ancient am2+ mobo/cpu. replacing the am2+ system will be a gigabyte z370-hd3 i recently picked up, no clue yet on what cpu i’m going to get, an old perc h700 raid card, some spare 500gb 2.5 drives (until i can replace with bigger/better) and a wd 4tb blue and seagate 5tb.

now that thats out of the way i’m looking for suggestions on what drive to use as bcache for my future raid. would prefer a cheaper 120’ish or 256gb’ish, though if its 512gb thats fine too as long as the price is low, ssd thats stupid fast on a pcie3.0 interface with good write endurance. budget is $50 usd max.

although is it even needed with the perc h700?
also if mentioning bcache hasnt tipped you off yet i will be running linux not sure on what distro yet though.

yes i know old psu = bad it will be replaced… eventually

Given the age of the components, use a larger SATA SSD for both the OS and cache. You can have a 1TB SSD for about twice your budget, as that seems to be the sweetspot in terms of price/capacity ATM. As for brands, Samsung, WD and Kingston are fine, you may have some luck obtaining some decent Chinese SSD from Aliexpress or Ebay.