SFP+ and/or RJ45 switch

[stoyboy]

I have a few questions and I am hoping for some help understanding and help making a decision.

I am trying to understand the heat/power difference between a 4 port SFP+ switch with 4 x SFP+ to RJ45 modules attached to cat6 cables carrying 10g, vs having a switch that has 4 port rj45 10g connections with the same wires?

It was my understanding that the SFP+ -> RJ45 modules would produce more heat and use more power than a native switch that provides the RJ45 connectors directly.

Does the math change when some of the ports are connected to RJ45 that can only handle 2.5 or 1gb? or is the module power/heat cost constant no matter the connection type? I know that the math works a lot better when you use DAC SFP+ modules but some of the devices I have would not be able to take advantage of this.

So now that hopefully I understand the basics better, here is my actual setup and quandary. I have a simple little switch in my office, its a standard rj45 1g switch. I would like to upgrade this to 10g switch and I am trying to figure out what ports/switch would work best for me.

I have:
* 1 uplink from the router
* 1 Main Desktop PC
* 1 NAS tower
* 1 Server box
* 1 laptop with a ethernet->usb c adapter
* 2x other 1g devices

Ideally I would upgrade the nic on the main PC and the NAS tower to 10g as these are the main things I want to upgrade. I can also optionally buy a new adapter that handles 10g->usb for the laptop.

I know that i can get a 2xSFP+ NIC for the NAS and use DAC to the switch possibly using both port to combine it into a 20gb connection. I could also use an SFP+ DAC to the switch for the main PC, but the other connections are likely to stay as RJ45 including the uplink. Anyway looking at my options most switches that have both RJ45 and SFP+ only have 2 SFP+ ports and ideally I would want to have 3 (2 for NAS, 1 for PC). I also would want a 8 port switch so i was considering getting an 8 port SFP+ and using the SFP+ -> RJ45 modules for the other devices. I want to know if that is still a good idea, or if I should just stick with an 8 port 10g RJ45 switch and get 2port RJ45 NIC for the NAS/PC.

Thank you for all the info and help.

 

[nexox]

Power consumption per port can go either way depending on the specific hardware, but usually RJ45 ports built into the switch are easier to cool because the power consumption isn't inside a little module that's almost fully enclosed in a sheet metal cage. The latest 10GBaseT modules rated for 100 meter CAT6 runs do run reasonably cool, built-in ports running at lower speeds should use a bit less power.

2.5G may not be terribly easy to do with SFP+, many modules sort of support it, but lots of switches do not, so you end up going from 10G to 2.5G at the transceiver, which has very little buffer, so you can start seeing packet loss and performance worse than 1G. Most Mikrotik switches with recent firmware will support 2.5G link rates on SFP+ ports, but unless you use the Mikrotik modules (which run hot,) you may be on your own figuring out which are compatible.

If you can use two DACs then you'll probably come out ahead on power consumption using an SFP+ switch plus a couple 10GBaseT modules rather than an all RJ45 switch. If you can find a switch with an adequate number of 10GBaseT and SFP+ ports that isn't either crappy or super expensive then go for it.

You probably won't get much benefit bonding two 10G ports on your NAS, most implementations require many simultaneous clients to see a real performance advantage there.