Slowness as QTS grows in version number

[haru0]

Until yesterday both were running the exact same firmware (QTS 5.2.6.3195), apps etc.

The root cause should be the firmware QTS 5.2.6, we have confirmed that this firmware has excessive performance issues on older models and have removed it from the website. You can refer to this discussion about QTS 5.2.6

QTS 5.2.6.3195 build 20250715 Released

I run pfSense+ firewall and an nxFilter (ad blocker for network) in a virtual machine on a TS-453Be (90% of the time this architecture has been fine) and since upgrading to QTS 5.2.6.3195 I was dealing with incredibly slow performance and high cpu loads both on my NAS and in the virtual machine [and on my entire network]. I am sure if I checked, QNAP temps were likely raised as well. Speed Tests both through my network, from the firewall itself, and ssh’d into the QNAP were about 1/8th of my us…

I should ditch these old TS-251+ and buy some newer models, right ?

You can try downgrading “NAS new” to QTS 5.2.5 first, and it should become as smooth as “NAS old”.