TVS-872XT Slow 4k performance (Premiere Pro)

[Flabbjaxaren]

Hi!

We recently purchased a Qnap TVS-872XT for video editing in our Production company.
Right now the nas is filled with 6 Seagate IronWolf Pro 8 TB disks in a raid 5 configuration (there were only six available when we bought the nas but we are probably going to buy 2 more).
The computers we are editing with are different Macs, partly iMacs (the oldest from 2018) and I use a 2020 MacBook Pro 16". We connect to the ethernet with the QNAP QNA-T310G1T (through thunderbolt 3). From that adapter, through cat.6-cables to the QSW-1208-8C, and from that switch to the TVS-872XT (with the included cable).
Our read- and write speeds are great, both around 900-1000 Mbytes/s.
However, when I try to edit some 4k, XAVC-I Sony FS7-footage, Premiere Pro lags like crazy? Even when I use local scratch disks, it just jumps and stutters. Why is this?

/Gustav

[Bob Zelin]

please clarify -
you write -
"Even when I use local scratch disks, it just jumps and stutters. Why is this"

so when you are not using the QNAP, and you are using "local scratch disks" - it still stutters. Correct ?
And when you run AJA System Test or Blackmagic Disk Speed Test on your QNAP from your iMac with the QNA-T310G1T, you get 900 - 1000 MB/sec - correct ?
Please confirm.
Bob Zelin

[Flabbjaxaren]

Not exactly. When I go into "Project settings" in Premiere (in the project on my server) and choose local directories for cache and all that, but all the media and the project file are still on the server, the timeline still stutters.
Am I making sense? English isn't my first language but I hope I'm getting through.
In Blackmagic Speed Test I get 900 MB/s in write and 1000+ in reads, using 1 Gb file size.
Thanks for the reply! /Gustav

[Flabbjaxaren]

Tried editing in Davinci Resolve, and in there everything was smoooth... so i guess this is a Premiere PROblem (eheh..)