Currently i have a VPS with 1Gb Ram, dual core capped at 1.2Ghz each. Traffic averages at 17-18Gb daily, a large part of that (90%) is from a Wordpress site. Google Analytics registers about 40k visits each day.
My question is a load from 3 to 4 normal during peak times ? At peak there are about 70-90 people online. Pages load a bit slower than in off-time, but still acceptable.
Can be. It depends on how many clients your sharing that node with, and what they are doing. Also the bottleneck hardly ever is the CPU, most of the times it's IO bandwidth, so it will depend as well on the drive setup your provider has in place. (hardware RAID, software RAID, no RAID at all, etc)
Like others have said, it totally depends on the node itself... but I can guarantee you that I would have a site with 45k visits a day on a dedicated server. And it would easily be making a profit every month.
Yeah i know i should move to a dedicated box but currently don't have time and i still want to squeeze a bit more out of this VPS. Thus the question to see whether it's ok to keep up with current server load.
Another question: is it worth it to install memcache on a VPS ?