I had a QUAT SATA-HAT (v1.2) with pi 4 and and i have a problem. I installed the HAT with 3 hdds and 1 ssd (2.5) and i can mount all the disks. 1 ssd and 1 hdd at “normal” disks and 2 hdds with software raid 1. but my write speeds are awfull. The command [XXX = sda]
sudo hdparam -tT /dev/XXX
had cached reads up to 740MB/s and without cache
sudo hdparam -tT --direct /dev/XXX
up to 270MB/s this is okay and enoght for me, but if copy datas the speeds are 20MB/s without raid and 50MB/s with raid.
messured with the command (in the mounted folder)
dd if=/dev/zero of=tempfile bs=1M count=1024 conv=fdatasync,notrunc.
so my questions.
- which sata ports are the best for my raid hdds ore it makes no difference
- had anybode a idea, why the speedtest okay and the write speeds of all the disks are so bad?.
- what is the maimum speeds of the SATA HAT?
With best regards