Hi, I have recently started watching your videos. It has helped me a lot with my first NAS so thank you very much for helping people like me every day! I bought a Synology DS220j a few weeks ago but I returned it after getting frustrated with lags and holdups due to 512mb ram and instead bought a DS920+ with 4gb added ram module, after your recommendations. I am so confused about the transfer speeds. I have a new cat 6 cable as well as 1000mbps connection in the network settings. But for some reason, I only get 20-30MB per second transfer speed. Sometimes it fluctuates to 40MB per second but sometimes to 10 for a little bit. I spent hour plus with Synology's help desk online. The agent couldn't help me. My computer is directly connected to the router which is connected to Synology he said that these speeds are normal. I have my chat transcript emailed to me as well which I am happy to share. I sent the agent a screenshot of 13MB per second transfer and he said this
There are many factors that can affect performance. The most common reason is file types. You will notice that movie files will copy much faster than text files.
Here is Synology DS920+ tests with 3GB file performing at speeds around 94MB/s https://www.synology.com/en-uk/products/performance#4bay
Cable quality can also affect the speeds. Also other data transfers via this network. If it is WiFI there could be so much interference and other devices making it slow.
Also, NAS itself might be busy with things like transcoding or receiving computer might be running apps in the background.
You can try to run some tests with Black magic or AJA free testing software.
I hope this helps.