It's a bit early in the game to have a stockpile of NVMe solid state drives in need of a new lease on life. Nevertheless, if you're willing to spend a bunch a money on four of them, you can get blazing fast file transfers with this new add-in card from Asus.
The new Hyper M.2 x16 Card (V2) is actually a retooled version of the one Asus released a couple of years ago. It has an upgraded power supply that can push 14W of power per drive, and a redesigned PCB that allows the active cooling fan to push air from the bottom to the top of the NVMe SSDs, rather than the other way around. This is presumably so the NVMe connectors won't get in the way of airflow.
Fully loaded, this PCIe 3.0 x16 card can transfer data at up to 128Gbps (theoretical maximum). That is equivalent to 16,000MB/s, or 16GB/s. The caveat, other than the overall cost, is support.
"Hyper M.2 x 16 card V2 is compatible with Intel Virtual RAID on CPU (VROC) and the AMD Ryzen™ Threadripper platform for NVMe RAID support. Unused CPU PCle lanes can be assigned to storage, allowing you to create a bootable RAID array with multiple M.2 SSDs," Asus explains.
On compatible Intel systems, support is further restricted to only Intel-brand SSDs. Otherwise, this can used on Intel X299, Z370, and Z390 motherboards, and AMD X399, X470, B450, X370, and B350 motherboards. While not listed, we imagine it would also work in upcoming X570 motherboards.
Asus has not announced pricing for this new iteration, though there are a couple of marketplace sellers on Amazon that have it listed for around $66.