Hardware differences- 6506 and 6509

[gregwoodson]

I have a 6509 and a 6506- same IOS version and flavor, same hardware, etc.  One supports rate limiting on the VLAN interfaces, the 6509 says "not supported due to hardware".  What is the difference here?  Im very confused on this since I was under the impression the chassis were the same- just in size.

[gregwoodson]

The actual message states- "Rate-limit command is not supported in hardware  use service-policy command"

Now I understand that I can use the service policy command here- but it would be MUCH easier to just rate limit the interface.