using hdr lots of noise, jpg no noise

I’ve got a folder with a bunch of hdrs and their simple counterpart jpegs. When I use the hdr in some scenes it’s just heavy noise and fireflies, but with the jpeg it’s fine. What’s going on there? Is there some nodes or clamping or setting I need to be using for the hdrs?

Have you tried using a higher resolution for the environmental MIS sampling (small areas can require resolutions up to 2048x2048)?

I’ll give it a try thansk.