I am using MRTG + RRDtool to monitor the bandwidth on each switchport of a Cisco Catalyst 2950 via snmp. Is MRTG capable of generating an hourly graph? With RRDtool I was able to set the interval to 1 minute in hopes of getting a more detailed graph, but the shortest timeframe the graph is 'Daily' graph (5 Minute Average) and the image is too small.

What I am looking to get out of this: I am looking to be able to visually monitor all of the switch ports and tell when port begins to have unusually high traffic, in real time (1 minute interval of snmp poll, graphs generated, and page refreshed).