Re: PCIe adapters supporting long distance 10GB fiber?
But what foundation do you have for asserting that switch hardware is any different in this regard? I can say that we are using 80 km modules in various hardware without any issues. I admittedly do not use any high power modules in servers, but I will need better evidence than this to assume that it would not work just fine. Den 20. jun. 2017 22.24 skrev "Denys Fedoryshchenko" <denys@visp.net.lb>: 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@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
But what foundation do you have for asserting that switch hardware is any different in this regard? I can say that we are using 80 km modules in various hardware without any issues. I admittedly do not use any high power modules in servers, but I will need better evidence than this to assume that it would not work just fine. For switches i guess it is same story as for PoE on them - total power budget matters. So if you will pack whole EX4500 with 10G 80km SFP+ it might have
On 2017-06-20 23:44, Baldur Norddahl wrote: problems as well, but for normal use, and if few only are "long distance/high power", at any case 3.3V supply rail by design in switch should handle many SFP, so if there is 48 ports, it should handle by specs at least 72W peak load. It might be multiple power rails for groups of ports, but still, much better than just 750mA on network card. But that's just guessing, i never seen circuit diagrams of good switches, or at least reference design, as it is all NDA material.
Den 20. jun. 2017 22.24 skrev "Denys Fedoryshchenko" <denys@visp.net.lb>:
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@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
On Wed, 21 Jun 2017, Denys Fedoryshchenko wrote:
For switches i guess it is same story as for PoE on them - total power budget matters. So if you will pack whole EX4500 with 10G 80km SFP+ it might have problems as well, but for normal use, and if few only are "long distance/high power", at any case 3.3V supply rail by design in switch should handle many SFP, so if there is 48 ports, it should handle by specs at least 72W peak load. It might be multiple power rails for groups of ports, but still, much better than just 750mA on network card. But that's just guessing, i never seen circuit diagrams of good switches, or at least reference design, as it is all NDA material.
Several of the limitations in switches/routers comes out to cooling, especially since there is a requirement for normal operation in case of failed climate control with ambient temp in the 40-50C range. -- Mikael Abrahamsson email: swmike@swm.pp.se
participants (3)
-
Baldur Norddahl -
Denys Fedoryshchenko -
Mikael Abrahamsson