The machine will store and serve millions of small files (<15Kb each), and all those files require a total storage space of 400G Considering the exact same SATA hard drives maker and models, on the exact same environment (OS, cpu, ram, raid controller, etc...)

which one of the setups bellow would be faster? A) RAID 1 with 2 drives of 2T each, making up total storage of 2T B) RAID 10 with 4 drives of 2T each, making up total storage of 4T

[EDIT]: I'm aware RAID10 is faster than RAID1. The larger the disk, at least in theory, the longer will take to do seeks/writes. So, will the performance gain of RAID10 will be outweighed by the "drag" caused the larger disk area when seek/write operations happened?