Will you install more than one SSD? The B75 chipset supports a single SATA III port; the other 2 are on the ASMedia ASM1061 controller that can be used for eSATA.
ASRock
- 1 x PCI Express 3.0 x16 (PCIE1: mode x16)
- 1 x PCI Express 2.0 x16 (PCIE2: mode x4)
- 2 x PCI
MSI
- 1 x PCIe 3.0 x16 slot
- 2 x PCIe 2.0 x1 slots
- 3 x PCI slots
If you'll never need the second PCI Express 2.0 x16 (x4) on the ASRock, then the less expensive MSI meets your requirements.