PCIe adapters supporting long distance 10GB fiber?

Denys Fedoryshchenko denys at visp.net.lb
Tue Jun 20 20:24:37 CST 2017


On 2017-06-20 22:07, Baldur Norddahl wrote:
> I would expect anything mounted in a computer to have all the power you
> could want. It is not like the ATX power supply cares about an extra 
> watt
> or two.
> 
> As I understand the issue it is more about cooling than power and is
> primarly a concern in high density switches were you could have 48 or 
> more
> to power and cool.
SFP needs 3.3V, it might be supplied from regulator on the card or 
directly PCI-Express,
can't be absolutely sure, in reference design it is just 3.3V_NIA and 
then filter,
also reference design SFP power circuit define max 750mA/3.3V max to 
SFP, thats only 2.475W.

FTLX1471D3BCV (10km SM) - up to 285mA
FTLX1671D3BCL (40km SM) - up to 400mA, and thumb rule in electronics it 
is better to not exceed 50%
of max specs of designed max current, as for many parts it is stated for 
25C & etc operating conditions.

I expect it might work, but noone knows how long, and how reliable, if 
it is not cooled very well.
And 82599 sensitive to cooling(it is very old card after all), as soon 
as it is not enough, it starts to glitch.

> 
> 
> Den 20. jun. 2017 18.09 skrev "Denys Fedoryshchenko" 
> <denys at visp.net.lb>:
> 
>> I guess it depends on NIC, there is many spinoffs of Intel X520 with 
>> much
>> weaker power supply circuitry.
>> It might work with good NIC, but you can't rely on it on long term, 
>> IMHO.
>> Even 40km Finisar SFP+ has Pdiss 1.5W. Also they mention: "The typical
>> power consumption of the FTLX1672D3BTL may exceed the limit of 1.5W
>> specified for the Power Level II transceivers"
>> If we talk about 80km, Pdiss is 1.8W.
>> While 10GBASE-LR is <1W
>> 
>> On 2017-06-20 16:30, Max Tulyev wrote:
>> 
>>> We use Intel NICs with SFP+ holes. It works good with long and short
>>> range SFP+ modules, including CWDM/DWDM.
>>> 
>>> On 15.06.17 12:10, chiel wrote:
>>> 
>>>> Hello,
>>>> 
>>>> We are deploying more and more server based routers (based on BSD). 
>>>> We
>>>> have now come to the point where we need to have 10GB uplinks one 
>>>> these
>>>> devices and I prefer to plug in a long range 10GB fiber straight 
>>>> into
>>>> the server without it going first into a router/switch from vendor 
>>>> x. It
>>>> seems to me that all the 10GB PCIe cards only support either copper
>>>> 10GBASE-T, short range 10GBASE-SR or the 10 Km 10GBASE-LR (but only 
>>>> very
>>>> few). Are there any PCIe cards that support 10GBASE-ER and 
>>>> 10GBASE-ZR? I
>>>> can't seem to find any.
>>>> 
>>>> Chiel
>>>> 
>>>> 


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