Dell Force10 Z9000 Reference Manual page 110

Parameters
2.4
3.2
10.4
Defaults 10.4
Command Modes CONFIGURATION
Command History
Version 8.3.1.0
Version 8.1.1.2
Version 8.1.1.0
Version 6.2.1.1
Version 6.1.1.0
Usage Save the configuration and reload the chassis for the changes to the epoch command setting
Information to take affect.
When using ten SFMs in an ExaScale chassis, the 10.4 and 2.4 settings are both line rate.
Additionally, the 2.4 setting has a lower latency.
When using nine SFMs in an ExaScale chassis, the 10.4 setting is line rate and the 2.4
setting reduces throughput. When the system has nine SFMs, Dell Force10 recommends using
the 10.4 setting.
Using eight SFMs in an ExaScale chassis reduces throughput at any epoch setting.
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Enter the keyword 2.4 to set the epoch to 2.4 micro-seconds and
lower the latency. This option is available on the E600i and E1200i E-
Series ExaScale systems only.
Enter the keyword 3.2 to set the epoch to 3.2 micro-seconds and
lower the latency. This option is available on the E600/E600i and
E1200/E1200i only. ExaScale does not supports this setting with FTOS
8.3.1.0 and later.
Enter the keyword 10.4 to set the epoch to 10.4 micro-seconds. This
is the default setting and is available on the E300, E600/E600i, and
E1200.
Added the 2.4 micro-seconds option. ExaScale supports only 10.4
microseconds and 2.4 microseconds with FTOS 8.3.1.0 and later.
Introduced on the E-Series ExaScale E600i.
Introduced on the E-Series ExaScale E1200i.
Introduced on the E-Series E300 (10.4 only).
Values changed as described above.
NOTE: The E300 supports only the 10.4 epoch setting. The E-Series TeraScale E600/E600i
and the E1200/E1200i systems support the 10.4 and 3.2 epoch settings.
NOTE: For E-Series ExaScale, the 2.4 setting is supported on FTOS version 8.3.1.0 and
later. The 10.4 setting is supported on all ExaScale FTOS versions. The 3.2 setting is
only supported on FTOS versions 8.2.1.0 and earlier.