Pinebook Pro 'xtreme'

[xyzzy]

I've been looking at adding 2 "features" to my Pinebook Pro. One applies to your comment about power & internal SSD, (aka NVMe drive). It appears that the eMMC is a pretty low power device, about 1 watt. Instead of adding a 4 watt, (or higher), NVMe SSD, what about adding another 1 or 2 eMMC slots? Make a new PCIe adapter board with a single or dual eMMC controller chip and 1, (or 2), eMMC slots, and then you can add 128GB, (or 2 x 128GB), eMMCs.

That wouldn't really work.  You'd need a specific ASIC that did PCI-e NVMe to eMMC translation in order to interface the eMMC to something that had a driver.  Or maybe use one of the Synopsis IP cores for an sdio controller and adapt it to PCI-e.  But I don't know of such a chip on the market.  If you used an FPGA then your power usage is shot all to hell right there before you even start with the flash.

But suppose such a thing existed.  So you have something that connects to PCI-e and looks like a NVMe or other storage device, then translates that control into block requests that it sends out through a non-trivial HS200 bus to an eMMC chip, which in turn does the FTL and translates block requests into actual actions on NAND flash banks.  We go from NVMe PCI-e TLPs on one end to NAND flash page and block ops on the other end.  With a bunch of stuff in the middle.

Now consider a normal NVMe SSD.  It goes from NVMe PCI-e TLPs on one end to NAND flash page and block ops on the other end.  Exactly the same.  But it uses a single NVMe flash controller, e.g. a Phison chip, to do this.  It avoids the middle step of converting to/from a HS200 bus.  Avoids putting the PCI-e interface and the FTL in two different chips.  And the flash controller is a high volume part that has had a lot of work put into it and uses a good fab process, to make it fast and cheap.

So really all this will have done is make an expensive and inefficient SSD.  If it seems like a NVMe SSD draws more power, maybe this is because one is comparing a 1 GB SSD that can do 3500 MB/sec to a 128 MB eMMC chip that does 60 MB/sec.

The solution is to use a small SSD and configure it to run at the lowest operational power state.