hmm...

i've moved my website to a bigger VPS which gave me 1GB ram and Dual Intel Quad-Core at another company, thinking it'd be a seamless migration shall i need to upgrade later, and that company do provide a one-VPS-one-Server package at same config.

but bleargh... even though site now do load significantly a lot faster but at peak time it sometimes return blank page, SSH return "bash fork : could not allocate memory", WHM/cPanel inaccessible.

how much ram does apache needs per 100 concurrent connection?

how big of RAM does a serious server should have? 2GB? 4GB?

between a Dedicated VPS (1vps/srv) and a Dedicated Server, how big is the difference in performance? is the vps overhead directly proportional to the server load?