6509 SFM x-bar speed question

[anotech01]

Just arrived on site - new project - has anyone had any performance problems with the SFM module. If you have an SFM card in slot 5, 2 16 port GBIC x-bar enabled cards, and 1 48 port 10/100 TX.

Would the switch:

A.) Run at 32Gbps on the 48 port 10/100TX, and 256Mbps on the 2 x-bar enabled GBIC blades

b.) Default to 32Gbps since all the cards are not x-bar enabled.

[csthomas]

I'm pretty sure the answer is b). You really don't want non-fabric cards in a SFM 6500. Although even without the fabric being enabled, you'd really need a lot of traffic to saturate the 6500s backplane. What does SHOW TRAFFIC say?

[Bill CARTER]

There are configuration commands to determine how packets are handle between 2 SFM enable ports and 1 SFM enable port and 1 non-SFM enabled ports.

To configure the switch to use flow-through mode if you have non-fabric enabled modules installed, perform this task:

set system switchmode allow bus-only

From the below link I belive the switch uses truncated mode to switch packets between SFM-enabled modules and the flow-through for all others. It's not really clear. Can we get someone from Cisco to clarify??

Hey Cisco, what is the answer? Do you need all modules to be SFM-enable for the SFM to get 256Mbps between any 2 SFM-enabled ports??

http://www.cisco.com/univercd/cc/td/doc/product/lan/cat6000/sw_6_3/confg_gd/swfab.htm#32032

http://www.cisco.com/univercd/cc/td/doc/product/lan/cat6000/sw_6_3/confg_gd/swfab.htm#20627

http://www.cisco.com/univercd/cc/td/doc/product/lan/cat6000/sw_6_3/confg_gd/swfab.htm#36373