Question about DEC740 SFP+ (home use)

[Monviech (Cedrik)]

I am not that firm in hardware, so I have a question to somebody more knowledgable about it than me, before investing money.

I'm thinking about purchasing a DEC740 because it looks like a great little box for home use. (I know its a bit more expensive than buying one of those ebay or aliexpress boxes, but I just want something reliable at home where I dont want to spend lots of time troubleshooting.)

My switch at home is a "MS510TXPP 8-Port Multi-Gigabit Smart Managed Pro Switch with PoE+ and two 10G Ports"

I wonder how to connect the 10G SFP+ Port to my MS510TXPP. I have seen that theres this " [DAC] NETGEAR AXC761 10G SFP+ PASSIVE COPPER CABLE 1M (MOST RECENT VERSION)" Cable which seems to be supported. And since it's Netgear it should also work with my Netgear Switch?

I've read a few topics and I've seen that the general opinion seems to be that DAC gets hot and is unreliable, is that true in a home setup like this where the port density is low?

Thank you all for your valuable input

PS:
If anybody is interested why I want to do that, my VM host is still Hyper-V and I want to pull the OPNsense VM out onto reliable hardware before Microsoft pulls the plug on the Windows support in the future. Before I change anything hypervisor related I need to have the network basics reliable.

[Patrick M. Hausen]

Use SFP+ for multimode short range fiber and a fiber OC3 or OC4 LC to LC patch cable.

It's not a matter of port density, the SFP+ to copper transceiver itself gets awfully hot.

fs.com is the best source for branded SFP+ modules. Buy whatever Deciso says for the OPNsense and a Netgear branded one for the other end.

[Monviech (Cedrik)]

Thank you.

Is there a general rule how short the multimode fiber could be? From the limited knowledge I have about fiber I remember that some SFP+ modules light the fibre at full power even though the fibre cable is short and that results in RX/TX errors.

For me it would be just like next to the switch, so I wouldn't go above 1m.

[Patrick M. Hausen]

Short range multimode can use 50 cm or 1 m.

[Monviech (Cedrik)]

Awesome thank you, now I have a general plan what to do. I'll report back once I have something up and running.

Also great tip with fs.com. Thanks Patrick.

[newsense]

Might want to consider 750 instead, looks like the new models are out with 2.5Gbe -- which is awesome

[Monviech (Cedrik)]

@newsense yes I've seen that. It's actually so great port wise. 3x 2,5 multigig and 2x 10 gig is awesome for that price.

I've just ordered the 740, it looks like it got 3 multigig ports too now.
https://shop.opnsense.com/product/dec740-opnsense-desktop-security-appliance/
"NEW! Now with 3x 2.5GbE port!"

Since I don't want to use zenarmor (cause I don't like it - !!my personal opinion!!) 4GB RAM is totally enough.

Also I chose the following for the Fibre Uplink to the Netgear Switch based on @Patricks suggestions, and a review of the DEC740 I found:

Code: [Select]

- SFP+ Optisches Transceiver Modul mit DOM - Cisco SFP-10G-SR Kompatibel 10GBASE-SR 850nm 300m Duplex LC MMF
- SFP+ Optisches Transceiver Modul mit DOM - NETGEAR AXM761 Kompatibel 10GBASE-SR 850nm 300m Duplex LC MMF
- LWL-Patchkabel, 1m (3ft) LC UPC auf LC UPC Duplex OM3 Multimode PVC (OFNR) 2.0mm
Even if the fibre link fails to work I can still hook it up to the 2,5gig ports on the Netgear switch I have.

[newsense]

Ah that's awesome, I was looking yesterday and only the x50 line appeared to have be changed

[vpx23]

Deciso could improve their datasheets by mentioning the used chipsets for the ethernet ports. I guess the 2.5G ports use Intel I226-V or I226-LM controllers?

[lilsense]

I'd recommend a AOC instead of the DAC or other means. It runs cooler and you replace once the whole thing instead of many when you are troubleshooting a physical issue.

[newsense]

Deciso could improve their datasheets by mentioning the used chipsets for the ethernet ports. I guess the 2.5G ports use Intel I226-V or I226-LM controllers?

99% sure it's gonna be igc with 226, Monviech should be able to confirm shortly.

[stevie]

Why are the old CPUs of the V1000 series still used? There is now the V3000 series.
The V3000 series has already been available for a year, replacing the V2000 series.

https://www.cnx-software.com/2022/09/28/amd-ryzen-embedded-v3000-zen3-processors-storage-networking-applications/

[Sparkey]

Here ya go.. newer V3C48
https://linuxgizmos.com/ryzen-embedded-3000-based-pc-equipped-with-up-to-6x-lan-ports/

[efahl]

I'm not sure where this "DAC uses more power" came from, but it's just the opposite.  I've been using 3 meter passive DAC for my switch-to-NAS connections for years, and they show virtually no power consumption increase on the meter when you plug them in, and are always cool to the touch.

https://community.fs.com/blog/guide-to-10g-dac-and-aoc-cables.html

Are people confusing RJ ethernet transceivers (which ARE hot power hogs) with DACs?

[meyergru]

I second that about DAC cables. While SFP+ to 10GbE copper transceivers get hot, DAC cables do not.
Generally, I have had no problems whatsoever with any and use them for short connections (in the rack or 3m max).