The company Small Tree Communications markets PCI-Express cards compatible with Mac Pro and Powermac G5 that allow a 10 Gbits/s connection between them.
These products function under Leopard thanks to the driver provided.
It will however be necessary to look hard at the price, the tariff of these cards is between $1295 and $3495 for one with an optical connection.
The price of the routers is also high. Count on $12000 for one with 12 ports.
If you do not have this kind of budget, wait a few years so that this standard is common place. Compatible products will have a price 50 or 100 times lower.
[translation by crispin]
