Either a fake or Sandisk has changed something ...?

I currently have a little experimenting the same stick from a friend at home and did it.
And I was very positively surprised by the write throughput of 45-50 MB / s.
Then I also bought me the stick and get on transfer rates of 12-15 MB / s.Desweiteren missing the new Stick 1GB of free space opposite the I already have. The transfer rate when reading is the same for both roughly. The stick I have because of the warnings given in other reviews ordered directly from Amazon and this will also get their original packaging.
Both sticks with CrystalDiskMark same USB 3.0 port tested with 1000MB Sequential Read / Write.
Therefore my tip: Check the direct stick upon receipt.

I get now sent a new stick after a complaint from Amazon and will bereichten once it has arrived.

EDIT: It stays with an asterisk. The new shipment has arrived. The stick now writes with about 20MB / s. Still far away from the 45-50 MB / s.
I'll stick to this now and buy me avoid the extreme version.

EDIT 2: Have the stick now again ordered elsewhere and it remains at a maximum of 20 MB / s write speed.
Thus is clear to me that Sandisk has previously built another store in this case and now installed slower memory in the same housing.