Another option than the mentioned CM4 module might be some RK3399 based SBC, such as the Rockpro64, which comes with a PCIe x4 interface (the Rockpro64 has a open PCIe slot so you could put in a x16 card too).

If you just want to hook up some M.2 NVMe SSD there are also other SBCs with the same chip such as the nanopc-t4 that come with a M.2 slot.

I wish something cheap-ish had more than a single M2, along with a PCIe.

I'm starting to realize you probably want SATA that can be powered independently.

I think I might not wait for Raspberry 4 with PCINVM...

Peripheral Component Interconnect Non-Volatile Memory; mouth full right there... express? tcho tcho! after espresso or just fast?

Why not get a CM4 with the IO Board? PCIe on the regular Raspberry Pi seems too niche for them to consider.

Because I make clusters: https://camo.githubusercontent.com/af3dccb802848a5f72d41c962...

My most recent one will have 6x raspberries with really nice heatsinks for the 4: http://move.rupy.se/file/pi_4.jpg

The cost of the CM and the ergonomics of the design makes this more expensive than going full Intel Atom!

And the Gflops/watt is exactly the same.

Are there any decent cases for the CM4 with the I/O board? Last time I checked there weren't any.

Not yet. I'm working on a couple designs that I'll 3D print for a couple of my own projects.

It's still hard to find both the IO Board and CM4 in stock though :(