Really Old TS-639 Owner Advice

[tt55du]

All,

Looking for some community advice here. I have an old TS-639 (6x3TB) that's still in good shape, but completely full. Get's used less than 8 hours a day (and not every day), stays off when I don't need, it's lightly used and is on very clean SmartUPS power. In addition to being full, the processor is way too slow and it can't keep up running apps and direct downloads from the ISP. It seems to cap out at about 4MB/s on the Broadband side, crazy in this day of cheap Gigabit FIOS that can provide 122MB/s

Since I believe the HW is still in good shape, I was thinking of one last and final hurrah upgrade of drives before I upgrade the NAS itself and retire the TS-639 after it's many years of solid service. I was looking to move all of my data into a crashplan service, adding the largest drives I can for a one time RAID5 build over 16TB, move all the apps to an application server, and just use the TS-639 as a dumb file server. I would also keep the crashplan service since you know, this NAS HW is pushing 8 years after all.

If not a stupid idea, Questions:
1. What is the largest drive I can add? The compatibility chart shows only 2 specific, 6TB drives for the TS-639 with new models supporting up to 10TB. Is this really true? I am not looking to expand, I know the 16TB volume limitation, looking to move all my data off and do a one time rebuild of a RAID5 over 16TB and move my data back on.
2. Do I really need new Trays? I see the new drives have different screw patterns, but if at least 2 of the screws line up, shouldn't that be enough to hold it in place? At $32 off each, that's enough to turn me off.
3. The latest FW is QTS 4.2.6 build 20170620. Are there any issues I should be aware of for this FW on such old HW?
4. Anything else I was too dumb to think of?

Is this is a stupid idea, Question:
1. Should I just stop being cheap and buy a new NAS? If so, is the TS-653A a good replacement? should I stick with Qnap?

Thanks for taking any time to help!

[travelsignposts]

I too have an old TS-639, never had any problems even though I'm using 6xWD Green 1TB (bought before they changed the recommendations!) in RAID 5. I would like to upgrade to 6xWD Red 3TB but I'm wondering whether this is advisable given the age of the NAS (bought at the beginning of 2009). I wonder what your opinion and experience is, as I note nobody has replied so far?

Cheers, Tony