I ordered a lot of S9's (January Batch) and all of them came with the Y.L. D12BM-12D Fan (yellow colored sticker). But one of them came with a Nidec Ultraflo fan. Putting my hand in front of the fans, it is clear that the Nidec is not as powerful as the Y.L.

Should I be concerned? Anybody else have that fan? It just seems weird to me that machines from the same January Batch have different fans.