HP's Microservers can cope with gigabit speeds and the AMD models are dirt cheap, both compared to poorly engineered "NAS" devices, and especially for what they can provide in terms of server level features.
I've had the older N36L model, an AMD Athlon NEO II processor with 8GB ECC RAM running for years with ZFS handling a few big spinning drives for storage, it's been quite nice and trouble free.
That beats my piece-of-junk NAS then! Thanks Freecom! USB3 and Gigabit Ethernet (and an always open SSH port 22 yet no responsive server on that address...)
I've had the older N36L model, an AMD Athlon NEO II processor with 8GB ECC RAM running for years with ZFS handling a few big spinning drives for storage, it's been quite nice and trouble free.