Good switches for iscsi

I have been using 5448 switches, and I used to think these were decent switches...  However, after trying to get decent performance out of some new MD3220i arrays, I now realize they have virtually no buffer.  :(  Look at the specs, and it's not even enough to buffer one packet per port if you turn on jumbo frames.

Barely oversubscribe iscsi, and it sends tons of pause frames, which not only pause the one connection, but any packets behind it which could be going elsewhere and thus totally killing performance.  (It's sad having to resort to tricks like disabling round-robin to get better performance, and not let a port talk to more than one iscsi array at a time, etc...)

Just annoying Dell claims these switches as iscsi optimized, when these are just bad switches for iscsi.  (End of gripe).

Can someone recommend some switches (Dell or other) that can do wire-speed gigabit and buffer a reasonable number of jumbo frames for several ports at a time?