Penta SATA HAT is now available

#21

In general I would better look than speculate and that’s what atop and /proc/interrupts are for :slight_smile:

IRQ affinity with RPi kernels is broken and as such cpu0 might be the bottleneck. That combined with ondemand w/o io_is_busy=1 and cpu0 while serving all interrupts might not even clock at 2400 MHz. And writes may generate twice as much IRQs compared to reads. But that’s speculation and it’s really easy to check for this with the aforementioned methods.

Also switching to performance governor might result in better throughput numbers since this masquerades parts of the problem (clockspeeds not ramping up quickly enough).

#22

It doesn’t seem like that’s the problem (testing with atop, monitoring cpu freq with vcgencmd, and also setting force_turbo—see my ongoing testing at https://github.com/geerlingguy/raspberry-pi-pcie-devices/issues/615).

#23

I have an extra Top Board if you want it. I watch your videos all the time and would be happy to send it along as a means of support.

The official case for the ROCK 4 works really well because the CPUs on those boards are on the undersides and the bottom of the case is essentially a big aluminum heatsink. Mine didn’t quite touch, so I bought some copper shims of various sizes to make up the difference. As a result, I have never seen the temperature of my CPU go above the high 30s.

Matt

#24

It seems the resellers are all out of stock of the Penta SATA HAT for Raspberry Pi 5.
Is there any ETA on stock?
Are there resellers in Australia?

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