Safety of using SFP Transceivers
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Hey all, couldn't find a clear answer on this through search. Wondered if there's something definitive about the safety of using an sfp to rj45 transceiver on the netgate 6100?
I have previously purchased the 10gtek in the accessories section for the device but noticed it gets insanely hot, almost scalding to the touch. Connecting gfiber to one of the SFP 10gig wan ports on the 6100 for context, 1m run from the jack.6100 is not rackmounted or cooled directly, in a residence so the only cooling it receives is ambient from the AC.
Any thoughts or recommendations would be appreciated. Thanks.
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@rentis I don’t think there are any official guidelines, but remember that the “upper limit” for human touch is about 45C, so the SFP module might be somewhere between 45 and 50C which i very likely within its own operating specs.
The 6100 is not going to suffer any damage from that, but the lifetime of the SFP is going to be shortened because of the heat.There is a huge difference between the temperatures and power consumption of “old” cheap SFP+->RJ45 modules and modern lower power ones (which comes at a cost).
Since these sfp’s does protrude quite a lot from the SFp+ cage, you might consider getting a small adhesive radiator to stick onto it - or even get a custom radiator made specifically for SP modules. To aid it sheeding the excess heat:
https://www.digikey.dk/da/products/detail/ohmite/WV-T220-101E/2071311
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Indeed they are designed to run hot. You're using a 10G transceiver? Those certainly run significantly hotter. I would try to use a DAC or fiber instead if you can.
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The heat is a big(!) problem. Especially since some some switches are activating fans (= noise!) is they see a hot SFP-module. The SFP-cooling inside the various switches is mostly almost 'none'
So I have been experimenting with heat sinks made for other purposes without significant success. (one of the reasons I am using fiber where ever possible).
So I was very interested in your link to a heat sink. Problem is that the suggested heat sink it self is not very expensive, however the cost added for delivery is sky high! (here in the Netherlands)
Do you have practical experience with this heat sink?And you are right a power dissipation from about 2.5 watt is quite common, however there are recent modules dissipate 'only' 1.5 watt.
Again the question do you have practical experiences / can you advice? -
@louis2 I have quite a lot of experience with SFP+ RJ45 modules and generally speaking I have had to many “early failures” (within 2-3 years) of the cheap powerguzzling/hot models. I have never had issues with neither the switches nor pfSense boxes where those modules have been used (apart from when the modules died early).
The heat sink I linked to is not specifically designed to SFP modules, I’m not even sure it will fit. It was just an example link showing that there are manufactures that makes specialty heat sinks. I have never used anything but a cheap 10x10mm small adhesive heatsink on modules running hot, and like you learned, it doesn’t really help a lot - but a few degrees also matters ;-)
In my opinion there is only two options:
1: Spend the money and get one of the modern modules with a Max rating of about 1.5watt and apply a small heatsink. That will get you the coolest running and most durable setup.
2: Accept they are hot (but within their design limits), and just run with the ones you have. Most of the rest of the world does, so…..
But I would still apply the little adhesive heatsink. -
Thanks, note that my main problem always have been noise!!!
I own a very capable Mikrotik CRS317 switch, but with a IHMO disgusting thermal design. Noisy fans really cooling nothing and and SFP+ cases without heat sinks. I did replace the fans with Noctua fans, does not help enough. And later on using a big Noctua fan in the lid of the case (that helps).
It was not the CPU which did ramp up the fans, it where SFP+ to RJ45 modules!
With as additional issue that the fans air stream can not cool those modules at all !At this moment, I am not using the CRS317 with as main reason 'noise' .
(I am using a less capable but good completely silent TP-link SX3008F at the moment)However for certain connections where fiber is no option, I will perhaps use SFP+ to RJ45 modules yes or no in combination with the CRS in the future, however only if that is possible without fan noise!
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@louis2 said in Safety of using SFP Transceivers:
At this moment, I am not using the CRS317 with as main reason 'noise'
It's a bit off topic but: I'm very, very picky about noise, everything in my office is fanless.
I do use a CRS309 (and a UniFi USW-Aggregation), that is only 8 ports but for the price of the CRS317 (I also got one but too loud with RJ45 adapters) you can get two CRS309 :). 3 of the eight ports are with 10G RJ45 adapters.Your TP-Link looks good too (and cheaper), are you happy with it?
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Another option would be to go with a SFP+ to RJ45 media converter, e.g. something like this perhaps:
https://www.fs.com/products/101476.html?now_cid=1038
Uses a bit more power than just a SFP+ to RJ45 transceiver, but heat wouldn't be an issue.
I have used lower power SFP+ to RJ45 transceivers as well (if I recall correctly power consumption was around 1.8 watts or so) and never felt like they got excessively hot during operation.
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@louis2 I know how you feel. I have the same pickyness/sensitivity for noise and everything is completely fanless with me because of it.
The only thing that does have fans are my Arube CX-6100 switch (replaced with noctua fans).
For the very same reason I’m using fiber and DAC cables for 10Gbe interlinking, but if you have no SFP+ ports and only 10Gbe RJ45 on the other end, then I get your problem.It might not be the temperature of the SFP+ module that causes the fans to spin like crazy - just as often it’s because its not a 100% supported SFP+ module by the switch (where it can’t read the operating parameters of the module). Just so you know….
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Yep! Very happy!
However only eight ports. -
I did pull fiber optic to my servers and to my room and migrated all 10G in my "server room to fiber" as well. And placed a 2.5G main switch next to my 10G switch (Zyxel XMG1915-10E) in favor of less important connections. That setup is silent
Also a home build pfSense version in there using a near silent PC-setup.
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Ended up going with a mediaconverter as the temp solution. Stumbled on a shop locally that was selling them with a warranty and 30 day return window. Was hesitant on them given what most people say about them but the return window at least gives me time to decide.
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@stephenw10 I was, my biggest concern was the transceiver burning out the 10g SFP port on the pfsense box. The 6100 was a bit of a splurge to future proof for 10g and worried about anything that might reduce the lifespan.
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Hmm, well I've not heard of that happening on a 6100. But I couldn't vouch for all transceivers.
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We use lots of different 10G SFP+ at work. They do certainly vary, but rarely have over heating issues as long as they are in a high end switch/router such as Juniper, Cisco, etc.
We did have quite bad over-heating issues in a TP-Link SX3008 switch. The problem was the SFP cages, so we modified the switch adding cheap self-adhesive heatsinks. Attached pictures show the main board before & after. Approx 20degC SFP temperature reduction.
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@stephenw10 I too had been using a 10GTek SFP+ module in my 6100 but was concerned about the very hot temps. The GUI reported module temps exceeding 70C which is nuts.
I researched and found these new FS.com "low power" (1.5W) modules and ordered one. It arrived yesterday from China and I was excited to see if it ran cool. Maybe it does run cooler, but it's still too hot to touch for more than 2 seconds, and the module does not self-report temps like the other one did, so I honestly have no idea. My cheap IR temp gun says it's 52C right now, but it feels as hot as the 10GTek one did.
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Mmm, well 52 is quite a lot less than 70. But those things just run hot. They are designed to run hot and mostly work fine like that. I wouldn't want my phone running that hot but....
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As I said above, it depends a lot on the SFP cage mechanics. I don't know what the internals of the 6100 are, so cannot comment on that.
For example, here's the vendor types & temperatures for a variety of SFP+ in a Juniper EX-4600. Ambient in the room is about 20degC.
PIC port information:
Fiber Xcvr vendor Wave- Xcvr JNPR
Port Cable type type Xcvr vendor part number length Firmware Rev
0 10GBASE ER SM Arista Networks SFP-10G-ER 1550 nm 0.0 2
1 10GBASE LR SM FS SFP-10GLR-31 1310 nm 0.0
2 10GBASE ER SM MENARA NETWORKS 5ER0P2U-1310 1310 nm 0.0
3 10GBASE LR SM FINISAR CORP. FTLX1370W4BTL-E7 1310 nm 0.0
4 SFP28-25G-BASE-CU-5M n/a JUNIPER-1P1 1P153A n/a 0.0 REV 01
5 SFP28-25G-BASE-CU-5M n/a JUNIPER-1P1 1P153A n/a 0.0 REV 01
6 GIGE 1000T n/a FINISAR CORP. FCLF8521P2BTL-TR n/a 0.0
8 10GBASE USR MM TIBITCOM TXM-MPOLT-01EES 1577 nm 0.0
9 10GBASE LR SM SumitomoElectric SPP5300LR-J6-M 1310 nm 0.0 REV 01
10 GIGE 1000T n/a OEM GLC-T n/a 0.0
11 10GBASE ER SM HI-OPTEL ECI HSFP101541LECI 1550 nm 0.0
12 10GBASE ER SM PROLABS ER-SFP10G-47-LGI 1470 nm 0.0
13 10GBASE LR SM LG1 SFP-10GE-LR 1310 nm 0.0
14 10GBASE LR SM Arista Networks SFP-10G-LR 1310 nm 0.0 7
15 GIGE 1000T n/a OEM GLC-T n/a 0.0 ^x
21 10GBASE LR SM FINISAR CORP. FTLX1475D3BNL-TR 1310 nm 0.0
22 10GBASE SR MM LG1 SFP-10GE-SR 850 nm 0.0
23 GIGE 1000T n/a WORLDWIDEPACKETS XCVR-000CRJ n/a 0.0{master:0}
reading-sw-01> show interfaces diagnostics optics | match temp | except high | except low
Module temperature : 40 degrees C / 105 degrees F
Module temperature : 38 degrees C / 101 degrees F
Module temperature : 36 degrees C / 96 degrees F
Module temperature : 40 degrees C / 104 degrees F
Module temperature : 44 degrees C / 111 degrees F
Module temperature : 34 degrees C / 94 degrees F
Module temperature : 41 degrees C / 106 degrees F
Module temperature : 34 degrees C / 94 degrees F
Module temperature : 30 degrees C / 87 degrees F
Module temperature : 35 degrees C / 95 degrees F
Module temperature : 34 degrees C / 92 degrees F
Module temperature : 29 degrees C / 84 degrees F
Module temperature : 33 degrees C / 91 degrees F
Module temperature : 32 degrees C / 89 degrees F{master:0}
reading-sw-01> show chassis environment
Class Item Status Measurement
Power FPC 0 Power Supply 0 OK
FPC 0 Power Supply 1 Present
Temp FPC 0 Sensor TopMiddle C OK 47 degrees C / 116 degrees F
FPC 0 Sensor TopRight I OK 31 degrees C / 87 degrees F
FPC 0 Sensor TopLeft C OK 41 degrees C / 105 degrees F
FPC 0 Sensor TopRight C OK 29 degrees C / 84 degrees F
FPC 0 Sensor CPURight C OK 38 degrees C / 100 degrees F
FPC 0 Sensor CPULeft E OK 35 degrees C / 95 degrees F
FPC 0 Sensor CPU Die Temp OK 49 degrees C / 120 degrees F
FPC 0 Sensor QIC0 OK 38 degrees C / 100 degrees F
Fans FPC 0 Fan Tray 0 OK Spinning at normal speed
FPC 0 Fan Tray 1 OK Spinning at normal speed
FPC 0 Fan Tray 2 OK Spinning at normal speed
FPC 0 Fan Tray 3 OK Spinning at normal speed
FPC 0 Fan Tray 4 OK Spinning at normal speed{master:0}
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@stephenw10 Thanks. I've already somewhat wrecked the SFP cage of my 6100... somehow the old module got stuck in there, and no amount of jiggling would release it. I just kept pulling on it until it eventually came loose. Now the modules no longer lock/click in place they just sort of slip in and out.
The thermals on the CPU itself seem "ok" and tend to hover right around 50C:
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I just would like to add here, that the thermal design of many switches is ... bad not to say very bad.
The cooling of SFP+ cases should be much much better !! And earflow of fans should be routed along things which have to be cooled and not just blowing towards ... nothing!
I general like MikroTik but it also an example of bad thermal design. Worse it is very hard if not impossible to correct that with extra coal fins.
So complain towards the switch designers and if possible ...
- use fiber
- or SFP+ to 1G utp
- or at least use the latest sfp+ to 10G modules''
Personally:
I migrated all 10G connections to fiber in my server cabinet. And also to 10G connections in other rooms .... not so easy.And replaced the small fans in my Miktotik CRS317 with a 12 inch fan in an home made lid :(
But as said it is ridiculous that that is necessary!!
