Magma has introduced the ExpressBox4, an external PCI Express expansion box designed to work with Macs and PCs. It costs $2,399.
The slots are equipped to be hot-swappable. Included with the chassis is a PCI Express (PCIe) host controller card that goes into a host computer or server. Each slot can operate any combination of 1x, 4x, 8x or 16x PCI Express cards.
System requirements call for Mac OS X 10.4 or later.