Good:

-ARCH synology certified ram modules

-Synology modules (of course)

-SK Hynix ECC Double-Rank So-dimm (few options, see posts)

-Samsung M474A2K43BB1 - CRCQ (16GB ECC) -2400mhz

-v-Color 32GB (2 x 16GB) ECC SO-DIMM DDR4 2666MHz (PC4-21300)

-Crucial mta18asf2g72hz-2g6e1

-16GB Kit 2x8GB DDR4-2400 PC4-19200 ECC SODIMM 2Rx8 Memory by NEMIX RAM

-Crucial 16GB DDR4 2666 (PC4-21300) CL19 ECC Unbuffered SODIMM CT16G4TFD8266

-Micron MTA18ASF2G72HZ-2G6E1 16GB (1x16GB) 2666MHz DDR4 SODIMM, ECC

-Apacer 8Gb ECC SOD DDR4 2133 CL15

-Memorysolution D4ECSO-2666-16G

-Dell ab489614

- v-Color 64GB (2 x 32GB) ECC SO-DIMM DDR4 2666MHz (TES432G26D819K-VC)

- Micron MTA18ASF4G72HZ-2G6 (1 module only, anyone confirm 2?)

- v-Color 64GB (2 x 32GB) ECC SO-DIMM DDR4 2666MHz (PC4-21300)TES432G26D819K-VC

- 64GB Kit 2x32GB DDR4-2666 PC4-21300 ECC SODIMM 2Rx8 Memory by Nemix

- M474A2K43DB1-CWE(dell)

Bad (works fine with a message):

-Kingston ECC modules

-Transcend 16GB ECC modules TS2GSH72V1B

NON-ECC (Not Recommended, but works with no errors)

-Integral - IN4V16GNELSI

Last update 5/8/21

궁금하여 검색하다보니 저런 정보가 있어서 올려봅니다. 

지금보니 제 시놀로지는 4GB였군요.  ㅠㅠ

업글 해야 곘습니다. ㅎㅎ

..............  링크사이트 들어가시면 좀더 정확하게 알수 있습니다.