I need to render in 100 million block on a server i own for a big new project i am starting , my problem is the server cant render the blocks fast enough (It's doing 1 layer of grass on layer 70 that is 10,000x10,000) we really need to get started on the map building if we want to launch this in a year. any suggestions?
Using WorldEdit for this will crash your server, as it cannot handle such an operation. As a result, you should use MCEdit instead. It will take a while, but big edits like this absolutely need to be done in it. Once you are done, you can start using WorldEdit on your server. If you are doing lots of terraforming, you should probably also use VoxelSniper.
As Dillmo said, MCEdit is definitely the best way to do a landmass of over 1,000,000 blocks cleanly and simply.
Another in-game alternative that I use myself is a plugin called AsyncWorldEdit. What this plugin does is change the mechanics for how the //paste command works by pasting whatever is in your clipboard at a rate that a Minecraft server can handle (i.e. [x] amount of blocks per tick). This is a great way to prevent WorldEdit from lagging out or crashing your server because it spaces out the pasting process to your server's TPS.
I used it myself for a paste that was a couple of million blocks total, and it handled it like a champ. It took about thirty minutes, but the entire paste in my clipboard was able to be pasted flawlessly into the game without taking the server offline or editing in with MCEdit.