PCIe x4Ch

[domi]

The 3rd gen. X1 Carbon I'm interested in can be configured with either of the following two SSD's:



The 256GB SSD is "PCIe x4Ch", while the 512GB model is only "PCIe". Would that make the smaller drive better/faster? Don't they use the same interface and offer the same performance?

tabook.pdf, OTOH, lists the following specs for storage:



Why both "PCIe 2.0 x4" and "SATA" are listed? Why would anyone use the SATA interface in the X1 Carbon?

[fb1996]

Both the 256GB and the 512GB Samsung SM951 SSD are PCIe x4.
However, the performance of the 512GB model should be slightly better.

The M.2 slot of the X1 Carbon Broadwell supports both PCIe and SATA based M.2 SSDs with a length of 80mm.

SATA M.2 SSDs are cheaper than the PCIe M.2 SSDs, so that's the reason why some people choose to buy an X1 Carbon Broadwell with a SATA M.2 SSD.

[domi]

Thanks, good to know! I plan to go for the 512GB Samsung, despite the rather high premium.