salmo

I have an older Corsair AX860i that I bought in 2014 and I see that Corsair's AXi power supplies are rated as Tier S. Is this the case for the older models too, specifically the one I have? I am planning on buying a new computer and use my current one as a NAS/Plex server and want to know if I should keep the AX860i for the NAS and buy a better quality power supply for my main PC or if I should buy a "lower end" but still acceptable PSU for my NAS and use the AX860i in my main build.