the last QNAP I installed (a TS-1677XU-RP) - the IT guy purchased Crucial RAM and it did not work. I strongly suggest that you pay the few extra bucks, and get the QNAP RAM. And if you simply refuse to do this, there are "QNAP imitations" on Amazon that are really cheap - I would trust those to work before Crucial, Micron, Kingston, etc. I am sure you have used Crucial throughout your entire career, but this is one time I must recommend against it.

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The correct QNAP RAM chip is $263

this is an imitation for 70 bucks

https://www.amazon.com/Tech-TVS-472XT-TVS-672XT-TVS-872XT-Servers/dp/B07VMP6QLQ/ref=sr_1_2_sspa?keywords=QNAP+RAM-16GDR4T0-SO-2666&qid=1581963905&sr=8-2-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEySVZHQ0tKUUlWMFBQJmVuY3J5cHRlZElkPUEwMDY0ODE2MkpWVjFONkxTNElLWSZlbmNyeXB0ZWRBZElkPUEwMTc4NjQ1MU9JTE9SV002N0ozSiZ3aWRnZXROYW1lPXNwX210ZiZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

Bob Zelin