Might be of interest to this group that memcached can be run pretty trivially at user-space using the OpenOnload accelerator software. There are a couple of deployments out there. One report I got was that request times were halved at 212K tps. I blogged the result here:
http://10gigabitethernet.typepad.com/network_stack/2011/01/memcached-onloaded-.html More information on OpenOnload can be found at www.openonload.org . It's a GPL project, currently running on Solarflare 10G Ethernet NICs (vendor plug). Best Steve
