Hi. I have crappy CAT5e cables routed around house and I'd like to push 5G or preferably 10G over them. I wonder which option is likely to deliver better results in terms of speed with underperforming cables - S+RJ10 module and some SFP+ based switch like CRS317 or native 10G ethernet switch like CRS312? My money is on CRS312 but I'd like to hear second opinion.
Cables should be under 30m but they're CAT 5e sooo... I'm kinda pushing my luck there with my hopes for 10G 
For one, if the cable is properly terminated and not too old you can get 5gigabit to 100m, 10 gigabit probably to 50meters.
If the cable is bad or old or not properly terminated, it doesn't matter what you're plugging it from or into, that doesn't really change anything.
The whole point of sfp to rj45 is to have sfp switches but you also have an option to cable a rj45 ethernet cable into it if you must (don't do it, huge waste of energy, thermal issues, stuff frying cages and itself if not properly cooled etc etc)
So to answer your question about what it would be best to plug it into, is just a good old rj45 ethernet port on whatever already has it built into it, don't waste a sfp slot for it.
Oke. Cables are not terminated yet but I bought Cat6a plugs and I'll be terminating them soon. Not sure if it's gonna change anything but I wanted to still increase my chances as much as possible. Cables are new, house is 3 years old.
I was mostly interested whether transmission power and voltages are the same for SFP+ and native copper. It seems that copper SFP+ are very power hungry so I thought that maybe it's because they have higher Tx power or something. But if that's not the case then CRS312 will be much cheaper option
Here are some basics that should give you a starting point so you can evaluate if the wiring in your house can be an issue:
The major difference between CAT5, CAT5E, CAT6, CAT6A, CAT7, and so on... is how these cables are built:
All categories of cables have 4 pairs of wires, and the wires in each pair are twisted around each other. This is the most important part, as twisting them around each other is exactly what allows parasitic noise induced in each pair to be cancelled (+noise -noise =0)
The higher the speed you want to push through the cable, the tighter the twist in each pair must be. This is what determines how good the noise is cancelled, and is achieved by selecting the higher category of cable. So the higher the category, the tighter the twist.
The higher the speed you want to achieve, the more you need to be concerned about nearby cables - sources of interference (cross-talk). If you take a close look at higher category cables, you will notice that pairs in high quality cables are carefully spaced apart. We are talking millimeter distances here!
The longer the cable, the more the signal will fade with distance. Here we are concerned with signal to noise ratio (SNR). Reduction in useful signal is called attenuation. Signal to noise ratio can be improved by picking the lower gauge cable (thicker copper), and again by increasing the twist, separating the pairs in the cable apart, and making sure there are no other high frequency cables nearby.
To improve noise cancellation even more, higher categories of cables come shielded. Notice that this is not as effective as twisting the wires, so you will only see the shield on very expensive cables.
A. High frequency appliances such as microwaves
B. electric motors (very common)
C. Radios in a very close proximity
D. Nearby servers with poorly grounded power supplies.
E. Dozens of Ethernet cables tightly packed together and running in parallel to each other over long distances.
F. Poor termination of RJ45 jacks
G. Water inside the cables (water doesn't increase the noise, but kills the signal)
My advise?
Don't loose sleep over your your CAT5E wiring. Industry has learned how to build these cables some 25 years ago.
Yes, the project is not up to spec, but you are not pushing the limits either.
Note:
1st, the short distance of cable runs in your house is the most important factor contributing to the very likely successful outcome of achieving 10G speeds.
2nd, this is residential setup, not an industrial facility with various noise generating equipment such as induction ovens and electric motors.
If all RJ45 terminations are properly done, the switches should be able to comfortably push 10gigabit and you shall not see TX/RX errors. If you do see errors, check RJ45 connectors, ensure proper grounding of all equipment, and switch off all motors and microwaves nearby when you run your network diagnostics. If everything is fine, start switching the noise generating sources one at a time.
P.S. I have exact same situation in my house and also upgrading my network to 10G with CAT5E wiring already laid inside the walls. There is nothing I can do about it, and I don't expect to have any issues. The current cabling has zero TX/RX errors at 1G speeds.
Good luck.
[Edit:] One more thing (Important)
Picking CAT6 Jacks is not as important as making sure your Jacks match your existing cables. Make sure the Jacks and the Wire gauge match, then look at the outer diameter of the cable (the sleeve) to make sure the RJ45 jack securely holds the cable.