Which Networkcards support busy polling?

Hi, I'm looking for network cards which support the low latency patch set from Eliezer Tamir (Intel) which has been merged in 3.11 [1]. For me it seems like that there is currently only a single NIC driver (ixgbe) which supports this feature?! I'm currently using some e1000e cards. How hard would it be to add this busy polling functionality to this driver? Or, why is there only a single card which supports it [2]? Regards, Steffen [1] https://lwn.net/Articles/551284/ [2] Not completely true, there seems to be another Mellanox card. But this one is far to expensive for me ;-)