First of all I have a SP3 that came from the factory with Windows 10 pre-installed. I have it updated to the latest patch level. When I put any SD card in the slot formatted with any filesystem (tested all 3) I notice system freezes at random times. I opened task manager and clicked the performance tab to see what is happening. During the freeze periods disk lists IO as 100%. This happens all the time with an SD card in but does not happen when one is not in the device. I have tried a 16g and 64g card one from PNY and the other Sandisk and it always causes the same issue. Wondering if anyone else with an SP3 factory installed with W10 has this issue with SD cards? It may be I have a defective device but I don't want to return it only to get one that is Windows 8.1 from factory. UPDATE: Took the SP3 into the Microsoft Store and they replaced it with another one with Windows 10 pre-installed. This one does not show any of the freezing symptoms at all. The only difference I can find is that the old one had a Liteon SSD and this one has an HK Hynix SSD. Both came from factory with Windows 10. The original one had a generic Windows label under the kickstand and this one still says Windows 8.1 Pro even though it came reinstalled with Windows 10. Since it was the SSD that was going into 100% disk IO, I wonder if this is a problem with the Liteon SSD's when using SD cards.