Why would anyone use these? They're popular?

[TangoWhiskey9]

This has over 100 sold Dual Port Desktop NGFF M.2 B + M Key SSD to PCI Express PCI-E 4X Adapter Card | eBay

One PCIe and 1 SATA but you need the cable for SATA. I don't get why anyone would buy that. What am I missing?

I was looking for 2x M.2 for cheapo Optane but they're all like that one.

 

[alex1002]

Some motherboards don't have the necessary slots. You can install a fast nvme drive a slower sata based drive for storage

Sent from my Nexus 6P using Tapatalk

 

[Logan]

@TangoWhiskey9 Amfeltec has 2x and 4x M.2 adapters.

 

[Patrick]

Here is a great use-case.

Use a Xeon D platform with either:
1U SuperMicro X9SCL-F 1U Server 3.5" 4Gb LGA1155 813M-3 5017C-MTF Half Depth | eBay

or mini-tower Amazon.com: Supermicro Superchassis CSE-721TQ-250B Mini-Tower with 250W Power Supply: Computers & Accessories

Both have 4x 3.5" bays for 3.5" or 2.5" drives.

You could then get a SATA M.2 for boot/ OS via the card, plus a SATA DOM which means six SATA devices.

You could have onboard m.2 plus that card's m.2 for two PCIe cards.

8 drives attached in small form factors.