Vanilla minecraft 1.4.6 with forge .473 runs fine. Just like 1.4.5 did filled with mods. However once I start add some mods... I keep seeing at times "can't keep up", the server lvl0 tick around 40-50ms with me on the server(alone). Once I disconnect the ms drops down to around 7-8(I assume the chunk is still loaded for a little bit). Then after a few minutes it's down at 0.660ms. But the worst part is the block flickering going on. Especially when you're digging downwards with you on the block.
What's wrong? What has *changed* since 1.4.5 that made a HUGE performance drop all of the sudden? Started up my old 1.4.5 server(45-50ish mods, ie ic2, bc, forestry, railcraft and so forth) and joined in, the lvl0 tick was around 15-20ms.
<edit> Forgot to mention that's with a CLEAN newly created world, each time.
Anyways, the computer running the server is a 2.7ghz dual core with 2gb ram. The server only runs a minecraft server, nothing else.