Z270 Taichi. SATA3 drive but in SATA2 mode

chong67 wrote: I have the Z270 Taichi motherboard and they all have SATA3 ports right? I have three Samsung SSD 850 EVO drives and they are all SATA3.  But two of the drive is in SATA2 mode. I read this from Samsung Magician software and running the Performance Benchmark numbers says two of the drives are indeed slower than one of them. Anyone know how to troubleshoot this? Thanks!

Yes, all the Intel SATA ports on a Z270 board are SATA III ports. But your board also has the add on ASMedia SATA ports, four of them. The four SATA ports at the bottom of the "stack" of SATA ports are the ASMedia SATA ports, labeled 15 and 16 in the Motherboard Layout picture in your board's manual. They are labeled as SATA3_A1_A2 and SATA3_A3_A4 on your board:

http://asrock.pc.cdn.bitgravity.com/Manual/Z270%20Taichi.pdf

Earlier versions of the Magician software would only recognize the main Intel or AMD SATA ports on a board, and I'm not sure if the latest version of the Magician software will now see drives on the ASMedia SATA ports.

The ASMedia SATA chipsets are called SATA III, but are only connected to one PCIe 2.0 lane from the Intel chipset. So while the ASMedia SATA ports are faster than standard SATA II ports, they do not provide the full speed of the Intel SATA III ports. That could be why the Magician software is showing the connection as only SATA II. The benchmark test results will be lower on the ASMedia SATA ports, above a SATA II connection but less than the results with the Intel SATA ports.

If you are only using the Intel SATA III ports, the SATA cable you are using might not be of good quality, or the connector is making a poor connection. Try using different or new SATA data cables.

Are you using any SSDs in the M.2 slots? The M.2 slots and the Intel SATA III ports share resources in the Z270 chipset. Normally if an M.2 SSD is in an M.2 slot, two Intel SATA ports will no longer work.