Upgrading QNAP NAS

[Shinta]

Yes, you could migrate to a bigger NAS such as 73A or even 74 series model https://www.qnap.com/en-uk/product/?cond...-6,3-3,5-1
This expansion will work with any NAS
Compatibility list https://view.publitas.com/qnap-1/tl-usb-...cht/page/1
Faster CPU will alow faster RAID rebuilding and 10GbE speeds.

I watched some more of your videos relating to NASs including one going over CPUs and one comparing QTS(ext4) vs QTS Hero (ZFS).  When comparing QTS to QTS hero I think I should stay with QTS so that I can easily expanded my current array by adding a single disks.  As such, I want to minimise potential RAID rebuild and scrubbing times.

I lowered my requirement for 10Gbe as I saw many of the units have PCI expansions so I can always purchase an expansion card and install that separately later.  

My current 4-bay NAS is very underpowered with only 1GB of RAM and an ARM CPU.  When scrubbing, I notice the CPU maintain around 100% CPU utilisation which suggests that the CPU is the bottleneck.

Follow up questions. 
1.  Assuming I remain with QTS and a RAID6 array with an expansion unit, will the CPU remain the bottle neck when scrubbing/rebuilding or at what point does the CPU no longer become a bottle neck?
2. I saw some of the QNAP CPUs have a higher thread and core count but lower clock speed than others.  I am not sure how QNAPs are programmed but can they take advantage of the increased core count when scrubbing or would clock speed be better to prioritise? 
3. Some the NASs I was considering have the CPUs listed below.  I ordered them in the cheapest to most expensive units I was considering.  I was wondering how I can determine the impact the CPU will have on scrubbing times.  For example, would a system with a Intel Core i3 8100T 3.1 GHz (Quad-Core) cut scrubbing times in half compared to one running with a  Intel® Celeron® N5095 4-core/4-thread processor, burst up to 2.9 GHz?  I assume there is diminishing returns which is why I am trying to balance the price vs the power of the CPU.

Intel® Celeron® N5095 4-core/4-thread processor, burst up to 2.9 GHz
Intel® Celeron® J4125 4-core/4-thread processor, burst up to 2.7 GHz
AMD Ryzen™ Embedded V1500B 4-core/8-thread 2.2 GHz processor
AMD R-Series RX-421ND 4-core 2.1 GHz processor (Turbo Core to 3.4 GHz)
ZhaoXin KX-U6580 8-core 2.5GHz processor
Intel Core i3 8100T 3.1 GHz (Quad-Core)
Intel® Xeon® D-1622 4-core/8-thread processor, up to 3.2 GHz
Intel® Core™ i5 Processor 6 core 1.7GHz, burst up to 3.3GHz
Intel® Core™ i5-12400 6-core/12-thread Processor, burst up to 4.4 GHz

Thank you again.