1 gigabit is roughly 100 megabytes sustained.
And the throughput you get as a nice big sequential read with 4K blocks and a queue depth of at least 8 is very different from a 50% random, 30% write 512b - 8k mxed block with a variable queue depth form 1 to 32. An 814 is absolutely not going to sustain 100 megabytes per second in the latter case. (Which, just by the by, best simulates my access patterns for having my profile and homefolders stored on the Synology while doing basic office work and streaming a blu-ray.)
Access patterns matter.