sate slotThese slots offer good performance for everyday tasks and are typically more cost-effective than PCIe-based slots. SATA slots are backward compatible, meaning you canSo a gen4 drive in the 3.0SATA slot will be limited to gen3 speeds, as will a gen3 drive in the 4.0 slot. But either will work just fine. So if you get one 3.0 drive, mht as well put it in