Lots of Snapdragon 835 Galaxy S8 units apparently have UFS 2.0 instead of newer UFS 2.1 memory. Should you care?
If this could help you make a bit more sense of the chaos, the leading theory – as developed and tested by users of the XDA Developers forum – is that all Exynos variants of the S8 and S8+ get UFS 2.1, all Snapdragon S8+ devices get UFS 2.1 as well, and some Snapdragon 835 Galaxy S8 units are on UFS 2.0. It's highly unlikely that we'll ever get official information by Samsung on the matter, but the company did remove the "2.1" spec from the S8 and S8+ online marketing materials. That's as good as it gets in terms of confirmation.
Should you even care about these specifics? If you put an UFS 2.0 and UFS 2.1 Galaxy S8 side by side, the chances you'll spot any difference – not just "significant", but any at all – are so slim they are virtually non-existent. That's because both standards are so blistering fast, they have eliminated storage memory as a performance bottleneck for the time being. Not that UFS 2.1 isn't a fair bit faster – read speeds are up to 300Mbps quicker, but again, this boost does not affect user experience in any obvious way.
Samsung can't be faulted for sneaking in some UFS 2.0 chips if its warehouses ran low on UFS 2.1 prior to the Galaxy S8 and S8+ launch date. But it wasn't particularly wholesome to market all phones as UFS 2.1 when this absolutely isn't the case. It isn't about the memory, but the principle.
source: XDA Developers