Although, as Leo notes, the Nexus series are the switches designed for DC usage, some Catalyst switches don't perform too badly in such a role (remember there was a time before there were Nexus switches). Generally, the Catalyst chassis switches, with the "right" line cards and/or supervisors, again, worked fairly well. Catalyst "fixed" switches, (most of such, but not all [i.e. there were a couple of "fixed" switches which had the guts of a chassis Catalyst, e.g. 4900M, 6840]), were really only suitable for user edge deployments where the traffic, per port, is usually much less than found on a server edge port. The 9300, basically, is one of the current gen Catalyst "fixed" switches.
Not ignoring the foregoing, it is possible/practical to use something like a 9300 connected to a busy server? Perhaps, perhaps not (also possibly more the latter than the former).
Sometimes "tuning" the switch's port buffering and/or using "uplink" ports, rather than using "ordinary" switch edge ports, can allow the switch to better support a very busy/active edge device ports.
Most Enterprise 21st century switches' ports are capable of "wire speed" with, or without, QoS enabled. What's often lacking in "user edge" switches is port buffering resources and/or "better" QoS support (for "better" management of congestion).
BTW, there is a "kind" of switch, that often has better/more hardware support for supporting high capacity Ethernet than a "LAN" edge switch, but possibly not as well as a "DC" switch, nor possibly not as expensive, either. That would be a "MetroE" kind of switch.
