The phrase "discernible difference" means that there is a noticeable or perceivable distinction between two or more things. It suggests that there are characteristics or qualities that can be easily observed or distinguished. Full definition
The only real discernible difference between the two devices at this point is form factor. (thenextweb.com)
The Note 8 meanwhile, runs on the Exynos 8895 or the Qualcomm Snapdragon 835 depending on region, so the S9 + is incrementally improved - although there's no real discernible difference in day - to - day performance. (pocket-lint.com)
With respect to hurricane damages, the chief and as yet only discernible difference between recent and earlier decades is that «There are more people and more wealth in harm's way.» (globalwarming.org)