Server performance impact...

Well since no one else has answered:

1.) I imagine the goal of implementing vBSEO is to increase traffic, so if you increase traffic, I imagine that yes load will increase proportionally. But this goes without saying... I not sure crawling will crawl more pages because while the goal is to improve some, many like the old archive now have the option of redirecting as a sitemap and there are additional nofollow tags to reduce noise/load from other non-content pages from being spidered.

2.) However, the old addage was "don't present dynamic pages as static" as well-behaving bots are supposed to spider dynamic content slower than static html pages soas not to overload servers. With vBSEO you will mostly likely rewrite as either /forum/ or /some-forum/some-title.html thus making everything look static, and thus telling all bots they can go "full speed", so I imagine peak spikes may be more.

Maybe others can comment on the effect this will have as well...

Originally Posted by titodj

I have my forum running in a dual, dualcore opteron, server with 4 gigs of ram.
On average the server load its between 2-4, But it goes higher during peak hours...
My question is:
Will VBseo have an impact on the server performance? and if So how big??
Regards....

VBSEO will add an additional load, though small, to your server once installed. As far as how much it will impact it no one can really tell you that. There are plenty of large sites running it though with similar hardware and they seem to be doing ok.