Trunk port vs Access port speed

[de fl]

I am setting up a 4900M for a temporary training class, for 1Gb connected client PCs.  I used a 10Gb interface with an X2-10G-SR which will connect via 62.5 micron fiber, to a 4948 10Gb interface with an SFP-10Gb-SR.  As for the config, I have the 4900M te1/1 setup as an access port to the 4948.  The connectivity is fine, as is the routing.  But when we use the client PCs disk connectivity (connecting to 10Gb storage) we get great read speeds but when it tries writing it slows down and eventually errors out.  

Question 1:  Would it make a difference if the 4900M was connected via a trunk port to the 4948?

I believe the issue is the length of the 62.5 fiber, and the maximum transmit\receive length of the transceivers, but I want to rule out the switchport configuration.

[Jon Marshall · Accepted solution]

I doubt very much if changing to a trunk port would make any difference.

Certainly not something I have ever come across.

Jon

[de fl]

Thanks.  You were correct, as changing the port configuration from access to trunk produced the same R/W speeds.  The issue was with the fiber run being too long for the SR trancievers.