As a side, and as Rob mentioned, an Intel CT card is defiantly a worthy alternative to any integrated NIC's. I've just popped one into my server, been running it for the last few days with some huge data transfers and backups. At 70-80 MB/s (about 60-70% throughput), the NIC is only stressing this ageing P4 by about 20%, modern CPU's will likely see 5-10% tops. The problem is now my main PC's ageing Intel NIC, doesn't have proper driver support under Win7, so i can't stress the server properly, have to use a second PC to stress it.
It's worth bearing in mind that, if you plan to make proper used of your NIC, as in, optimising, there are a slew of options that can be tweaked. Driver buffers, Flow Rate, Jumbo Frames, Adaptive inter-frames and interrupt moderation... as well as a mass of windows based tweaks with LanmanServer and LanmanWorkstation. The problem is that there are no 'best' options, since it's all changed depending on workload. For the most part, they all work 'as-is' without too much tweaking. 70MB/s for me is nothing to sniff at considering i was stuck with 12MB/s for the last year due to a dodgy integrated NIC, it would be nice to get 110MB/s... if the hard drive could take it, lol.
