i think you can get all that questions answered on the synology site itself
here's one example
https://www.synology.com/en-global/products/DS1515+#spec
- 512
- 256
- 512
i don't own any of those models above so i can't help review if that's also what you were asking for
HTH
Others review of synology
Mar 15 2016, 05:14 PM
Quote
0.0124sec
0.55
6 queries
GZIP Disabled