11-12-2019 01:52 PM
After perusing this and other forums looking for a definitive answer, there seem to be dissenting opinions on whether using the drive caddy and adapter cable in the HDD bay will allow 2280 M.2 NVMe SSD drives to utilize all 4 PCIe lanes. I want to know if there is a reason to shop for a higher end M.2 drive if I can't extract full performance out of it.
11-12-2019 02:13 PM
I don't have one to test, but the platform spec for the T480 says that some of the T480 machines have SATA drives and some have this: "M.2 SSD / PCIe NVMe, PCIe 3.0 x 4"
To me, that means is should use 4 lanes
11-19-2019 12:08 PM
Most of the forum posts regarding this issue suggest that the caddy/cable NVMe M.2 connection is limited to 2 PCIe lanes. Some of the posts suggest that the limitation is from the BIOS. I'm curious to know if that cable is able to carry 4 PCIe lanes, or whether it is the physical limitation. If not, it might be that a newer BIOS could release the missing 2 lanes (and yes, I know that in terms of real-world performance, there would be little observable difference between 2 and 4 PCIe lanes).