QUAT SATA-HAT writespeeds are awfull

#1

Hello

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.

  1. which sata ports are the best for my raid hdds ore it makes no difference
  2. had anybode a idea, why the speedtest okay and the write speeds of all the disks are so bad?.
  3. what is the maimum speeds of the SATA HAT?

With best regards

Chris

#2

Is tempfile located at sd card?

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#3

Hello, thanks for the answer

No, I am in the folder of the mounted disk. with Samba i hat create a nas and the folder size is the size of the disks, not the sd card, so I`m sure i copy the tempfile on the disks. If i copy datas with my network i have the same speed (20-30 MB/s).

#4

I have same setup (3HHD, 1 SSD) and good speed:
Did you ensure to change your path to your SSD (mine: cd /mnt/video4) before start dd

dd if=/dev/zero of=tempfile bs=1M count=1024 status=progress
987758592 bytes (988 MB, 942 MiB) copied, 5 s, 197 MB/s
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB, 1.0 GiB) copied, 5.54067 s, 194 MB/s

Regards
Michael

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#5

Hello,

I had 1 problem solved. I had used ntfs (not the best idea) at my ssd and with ext4 have a wirte speed about 200MB/s. Thats for the rates Michael.

Now I have nas speeds in my network about 80 MB/s HDD but my SSD hat speeds about 60 MB/s. I think it is a problem with samba, not with the SATA-HAT.

Thaks for your Help

Chris

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