10G networking is becoming more affordable. To sustain 4K workflow, I edit on my fastest 9900K workstation & render the most CPU-intensive output there while allowing my 2 other (slower Xeon) workstations to render various other client-requested files. A good example is when the client still wants Blu-rays & DVDs , wants different text messages in the lower 3rd for various audiences, allowing Mercalli 4 stand-alone to batch-render all-day w/favorite settings, etc... This requires having copies of the source video & VEG files on each workstation. Previously I had (2) Mellanox 10G PCIe cards in my main editing workstation & (1) card in each of the render workstations, but that setup had limitations.
Then I found a 10G switch for <$160 here: https://www.amazon.com/gp/product/B07HYKQFWD
(MikroTik 5-Port Desktop Switch)
Paired with $30 Mellanox PCIe cards found here: https://www.amazon.com/gp/product/B016OYD0D4
You can connect several workstations & a NAS in a small studio environment
For short runs use this: https://www.amazon.com/gp/product/B00U8BL09Q
($10 - $20 10G SFP+ DAC Cable)
I have a QNAP NAS mounted in a server rack in a back room.
To go the distance get these: https://www.amazon.com/gp/product/B00U8Q7946
($21 10 Gigabit SFP+ LC Multi-mode Transceivers)
And this https://www.amazon.com/gp/product/B07DP766QG
($20-$40 10Gb 50/125 Multimode Duplex Fiber Optic Patch Cable)
6-5-2019 EDIT: QNAP's new affordable 10G switches (QSW-308 & QSW-303s) are arriving soon, price TBA. Meanwhile their older 8-Port is discounted to $359 here: https://www.bhphotovideo.com/c/product/1413712-REG/qnap_qsw_804_4c_us_qsw_804_4c_8_port_unmanaged_10gbe.html
I routinely get 500-600 MB/s transfer speeds between workstations, mainly because that is the fastest speed of my current SATA RAID0 drives connected to PCIe 2.0 hardware controllers on my older Xeon workstations...