They seriously must have been doing something wrong. We scale to 2000 requests a second on a good day on one not very hefty quad core SQL server 2008 box with 16Gb of ram and 2 front end web servers and a virtual active directory host. The requests are between 2-4 SQL queries a hit as well and can return hundreds of rows with 6 way joins galore thanks to nhibernate. Latency per hit is always less than 80ms.<p>We've done literally no tuning as well. It's all out of box. It just sucks up the requests and spits them out with a smile.