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I'm looking to run 10 GbE over lengths of 5-25m for a research lab and have been shopping for the appropriate optics. I'm guessing a mix of copper direct-attach cables and OM3, OM4, LC/LC multimode fiber will suffice. But two questions cropped up while I was looking around:

  1. Why does it seem like Tripp Lite and Belkin sell most of the LC/LC multimode optical fibers while there's a much better selection for transceiver modules (Mellanox, Arista, Cisco etc.)? I know branding usually isn't a core issue (there are lots of redundant debates of this kind regarding mobos, HDDs etc.), but I tried searching up the history on the leading manufacturers on optical fibers for servers and couldn't find anything at all. What are some reliable brands for optical fibers?

  2. Are there any latency consequences for choosing single mode vs multimode? I know the deciding factor is usually the range, but our research is very latency-sensitive (particle physics).

Thanks!

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  • What do you mean by "sell the most..."? Obviously, LC/LC OM3 patch cords are manufactured and sold by the "usual suspects" in infrastructural cabling - Tyco/AMP/ADC, Corning, Panduit, Avaya/CommScope and others. Of course, Belkin and the Chinese have its share in the low-price segment, too. anixter.com/emea/euc/en/… Latency is only going to be a visible problem with 10GBASE-T - other transceiver types should have rather similar latency characteristics.
    – the-wabbit
    Feb 5, 2014 at 16:30

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The latency for SFP+ fiber optics transceivers is typically "better than 0.1 µs" for both, multi-mode short-reach links as well as single-mode long reach variants (latency for signal runtime excluded). The Direct-Attached-Copper (DAC) SFP+ modules are somewhere around 0.3 µs, whereas 10GBASE-T would be at 1.5 µs or 2.5 µs, depending on the configured mode / range.

This being said, available transceivers might do better than this. A Cisco datasheet for example states:

For in-rack or adjacent-rack cabling, the Cisco UCS 6200 platform supports SFP+ direct-attach 10-Gigabit Ethernet copper, which integrates transceivers with Twinax cables into an energy efficient, low-cost, and low-latency solution. SFP+ direct-attach 10-Gigabit Twinax copper cables use only 0.1 watts of power per transceiver and introduce only approximately 0.25 microsecond of latency per link.

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