Depending on just how complicated this expanded metal is that doesn't sound too bad.
Once upon a time, back in the Pentium days, I modeled a half cylinder of diamond mesh. It took about an hour and a half to rebuild. I don't remember for sure, but after a glance at Wikipedia I'm guessing your processor is probably about 7 times faster than the one I was using at the time so. . .
That said, the experts will tell you that for SW processor speed is everything.
hei'ya, you can check your needs here "http://www.solidworks.com/sw/support/SystemRequirements.html" , and the help file and make sure you have up to date drivers, although you don't mention your version of SolidWorks or the config.- kelef
If the expanded metal part is built with actual features, it can take a long time to complete a rebuild. Have you considered applying an appearance instead? I have had pretty good luck by applying a "chain-link" real-view appearance. These can be modified somewhat and do not slow things down as much as using a feature pattern.