Last time I asked around on 2.5G ethernet I was told to skip it and go to 10 Gigs straight as its “cheaper” and better than 2.5G. So I started to investigate and I am baffled by the costs. Let me break it down:
Quality 10G switch Mikrotik CRS305-1G-4S+IN ~150 $ (this seems reasonable)
10G SFP+ RJ45 modules - these are starting from 50$ on ebay from china which seems excessive, given i would need at least 4 of them.
10G NIC -Intel X540 T2 for around 40 $ if I want to go with RJ45. X520 with SFP+ connector can be had for 30$ but does not seem to worth it, given then price of SFP+ modules.
So I am somewhere around 430 $ for connecting my NAS and desktop PC via 10Gig. Compared to that, I can upgrade to 2.5G only for approx. 80 $
I could partially go with fiber instead of copper, pushing down the SFP+ module costs to 15$, but i still need at least one RJ45 module to run to my home PC. Also I am concerned fiber will bring some additional complexities that I am not prepared for (have zero experience with it).
Is the 10g on WAN or LAN I think is the real question here.
I think both costs are relative. You could argue 2.5g doesn’t make sense but it really depends on need.
If it’s WAN then I’d argue both cases are expensive.
If it’s LAN then maybe there is a minor cost difference between 2.5g and 10g.
Also just because the network is 10g doesn’t mean your gonna get 10g across the network. If WAN ain’t 10g not happening. If storage/NAS isn’t SSD or SAS not happening. If the motherboard doesn’t have enough bandwidth to support the 10g output then it’s probably not happening.