Today NetApplience folks has told me that Linux performance is twice better than FreeBSD when using em(4) driver, and they pointed out that the driver FreeBSD is using does not do a good job at this time. I have tried to tune some certain part of the kernel however the result is still not so good at the time I am writing.

I believe that FreeBSD _WILL_ be better once I have did some more in-depth analysis tomorrow – someone else has said that Linux outperforms FreeBSD 100% better when running databases, but without too much tuning I got much better performance with the same configuration the claimer said. FreeBSD is an operating system that consider stability more than performance, while it is possible to get better performance while retaining very good stability after some tuning.