About the SATA HAT category

#1

A complete NAS solution for ROCK Pi 4 as well as Raspberry Pi 4.

#2

Hello,

I hope that this is the right place to ask this:
Do the hats use the GPIO pins? Could you use two hats on a single Raspberry Pi?

Thanks,
FloGer

#3

From cnx-software.com for the context of my next post:

domih

Questions:

  1. Can the USB Quad SATA HAT for Rock Pi 4 be used simultaneously with the M.2 Extension board v1.4?

2a. If so, how does it work from an assembly viewpoint? Apparently the Quad SATA HAT needs to be directly attached to the Rock Pi 4 board with the 40 GPIOs. So where does the M.2 Extension board v1.4 go? Can’t be on top would block the SATA connectors. If moved to the bottom it’ll conflict with the thick bottom heat sink (with custom additional fans…) Vertical on the side?
2b. Does the proposed NAS enclosure account for it?
2c. Will Raxda sell a longer ribbon cable to let user rearrange the board in a custom case?

  1. Alternatively, same questions (1) and (2) for the M.2 to PCIe X4 adapter.

  2. Why does the USB Quad SATA HAT need the 40 GPIOs connector? Purely mechanical? Or do we lose all the GPIOs for good?

  3. Specs say “software RAID 0/1/5”, JMicron 561 says “Support hardware RAID0 (striping) and RAID1 (mirror)”. So, is RAID 5 supported?

  4. Is there any significant difference in performance using the JMicron 561 hardware RAID vs using software LVM raid or mdadm raid? After all, a 4 disks config allows for RAID 10.

Tom Cubie

@domih

  1. Can the USB Quad SATA HAT for Rock Pi 4 be used simultaneously with the M.2 Extension board v1.4?

This idea is crazy but we just checked, it’s possible! We can make a version of Quad SATA HAT with long 40P GPIO header passthrough(model number QF3L). The Penta SATA HAT can be only connected to the M.2 and power to work.

2a.

It depends on your preference of 2.5 or 3.5 inch disks. The case we made is for 2.5inch disks only, small and stands on the desk. For 3.5 inch disks, you will have to use some existing HDD enclosure for sure(with PSU inside).

2b.

No. the case we have now did not consider that.

2c.

Of course we can.

  1. Why does the USB Quad SATA HAT need the 40 GPIOs connector? Purely mechanical? Or do we lose all the GPIOs for good?

We need to use the GPIO for the top board, function includes 1 wire for temperature monitoring, i2c for 0.91 oled, JMS561 proper reset in order so that the disk device will not change each reboot, and pwm for fan control.

For the Penta SATA HAT, it can work without GPIO attached if you don’t need the additional feature.

For JMS561, there is no speed difference in software raid or hardware raid. We don’t use hardware raid because it’s confusing to users that we can not hardware mirror across two JMS561s, ie you can only set up hardware raid with disk 12, but not 13. So we just drop hardware raid and use more flexible software raid.

No. The bottleneck is on the USB 3 buses on ARM, not the JMS561.

For further info, you can discuss in the forum to keep the thread topic focused.

https://forum.radxa.com/c/hardware/sata-hat

#4

@Tom Thank you for the timely reply!

Regarding (1), I’m thinking about the following use cases:

(a) Run the OS from the eMMC, use an M.2 x4 PCIe NVMe SSD for LVM caching.

(b) Run the OS from the eMMC and use the M.2 x4 PCIe for a 10Gbe network card.

I understand that in both cases the bottleneck will come from the USB3, but for (b) with NFS async that would be “quasi-transparent” for write size < free memory for buffers.

“…Quad SATA HAT with long 40P GPIO header passthrough…” <-- Would be nice but then again, let’s see if other users ask for it.