Fibre Channel Naming Should
Match its Performance
The network technology named "10GbE" means throughput is 10Gb/s, and if
you're like most people, you would naturally believe the network called "32GFC,"
means throughput is 32Gb/s. The reality is the name matches the speed for
Ethernet, but surprisingly not for Fibre Channel. The speed of the network is
significantly less than the names for each generation of Fibre Channel.
If you care to know how many people were aware of this, how we got here, what
IT pros think should be done, and what the industry is going to do about it,
Who Knew Fibre Channel Names Don't Match
After talking to several Fibre Channel
industry insiders, I discovered it's
common knowledge that actual Fibre
Channel speed doesn't match the
number in the name. The next step was
to measure awareness of the disparity
in the IT community. IT Brand Pulse
conducted an independent, non-
sponsored survey of 200 IT pros, and
not surprisingly, the vast majority
expected the name "32GFC" meant the
speed of Fibre Channel is 32Gbps.
How This Happened: Speed-Based Naming
Is A Baudy Affair
Turns out since the technology was introduced, Fibre Channel
went through periods where it was named after its baud rate,
followed by the current time frame where Fibre Channel
naming is "generation-based."
After the dial-up modem industry faded away, Fibre Channel
alone carried the flag of using baud rate as their reference
point for naming. What should be used to identify each new
generation of Fibre Channel, is a well established convention:
half-duplex throughput in Gb/s. You can arrive at that number
by multiplying the baud rate by a factor for encoding overhead.
Using Gbaud for naming is, best-case, confusing and
somewhat irrelevant. Worst case, it is deceptive. (Watch
this video for an explanation of how Ethernet and Fibre
Channel performance are measured, and where the GBaud
During the time this 2008 road map was published, the product name was based on
the Line rate (Gbaud) specification. However, if you multiply Gbaud x the encoding
overhead factor, you arrive at the effective throughput number (and name) which is
apples-to apples with Ethernet naming. That means 1Gb FC was actually 850Mb
FC, and the technology entered the gigabit age at 2Gb FC, which is actually 1.7Gb
FC. Clearly the "Product" specifications in the chart are confusing or deceptive.
At 8GFC, the naming in the generation-based Fibre Channel
road maps was changed to 1GFC, 2GFC, 4GFC, etc. Oddly,
the entire SAN industry referred to the technology in terms of
Gbps, yet there was no mention of that specification in the
speed road map.
The intention isn't clear with this approach, but the results
seem very clear.
Result #1: the vast majority of people interpret the names of
each generation of Fibre Channel as network throughput,
when they are not.
Result #2: the market makes the easy translation to
throughput (the higher number), and voila!, 16GFC becomes
Result #3: the industry has plausible deniability, but many
customers are misled.
It is common for vendors and
industry organizations to drop the
Gen 5 / Gen 6 naming convention
and misrepresent the technology
as 8Gb, 16Gb FC, etc.
It Matters to the IT Community
Next, IT Brand Pulse asked IT
professionals what they thought of
this dilemma. About two-thirds of
the respondents answered, "Not a
big deal, but the Fibre Channel
industry should update their road
map..." However, the industry
should take notice that almost a
quarter of the respondents think
"This is a big deal, we have been
deceived for a long time..." Over 80% of IT professionals surveyed said the FC road map
should be fixed.
The Gap is Growing
This was not much of an issue is when the naming logic was "close-enough" at 1Gb FC
and the difference between name and speed was .15Gbps. But at 32GFC, the gap is
almost 5Gbps, and it's snow-balling.
On behalf of IT community, I'm calling on the Fibre Channel industry to update their road
map so the naming accurately reflects the speed of the network in Gb/s....just like we're
used to with Ethernet. To hold us over until then, IT Brand Pulse has created the Official
Fibre Channel Road Map Translator.
As you can on the next slide, we have taken the liberty of renaming each generation and
re-introduced "Gb" in the name. By looking at the name, users can easily make an apple-
to-apples comparison with Ethernet. I've also listed throughput in Gb/s, the well-
established convention for network speeds. By using this road map, you will no longer
need to convert from MB/s full-duplex to Gb/s half-duplex, in order to get the most widely
used specification for network performance.
Gross bit rate
(Line Rate in FCIA Road Map)
Effective bit rate
Gross bit rate x overhead
IT Brand Pulse Road
1GFC 1.0625Gb/sec 8b/10b .8 .85Gb/sec 850Mb FC
2GFC 2.12Gb/sec 8b/10b .8 1.7Gb/sec 1.7Gb FC
4GFC 4.25Gb/sec 8b/10b .8 3.4Gb/sec 3.5Gb FC
8GFC 8.5Gb/sec 8b/10b .8 6.8Gb/sec 7Gb FC
16GFC 14.025Gb/sec 64b/66b .9696 13.6Gb/sec 14Gb FC
32GFC 28.05Gb/s 64b/66b .9696 27.2Gb/sec 27Gb FC
64GFC 56.1 Gb/s 64b/66b .9696 54.4Gb/sec 54Gb FC
128GFC 112.2 Gb/s 64b/66b .9696 108.8Gb/s 108Gb FC
256GFC 224.4 Gb/s 64b/66b .9696 217.6Gb/s 218Gb FC
Official Fibre Channel Road Map Translator
Name that does not
match actual speed
Name that matches
In Industry Organizations We Trust
The networking industry is a highly-competitive arena with tens of billions of
dollars on the table. In spite of the high stakes and intense competition, the
industry organizations that document standards and specifications
have earned our trust by publishing accurate information about Fibre Channel,
Ethernet and InfiniBand. Traditionally, it's been left to vendor product
marketing teams to add spin to the basic specifications in the industry road
A shout-out to the Fibre Channel industry to take a serious look at this. If not,
we look forward to getting lots of views on the Official Fibre Channel Road
Map Translatorin the months and years ahead!