How to do <=1 Hz timelapse photography with Canon 7D?
The problem isn't the remote timing, it's the rate at which data can be written to the SD or CF card.  The camera can shoot a bunch of images quickly in burst mode because it stores them in an internal buffer for a short while before it writes them to memory.  However, this pace of data acquisition is not sustainable for long periods of time because the buffer will fill up before it can offload to the card.  The best thing you can do is make sure you're using cards with the fastest write speed possible.  Shooting jpeg only might also help, depending on how quickly the camera converts RAW to jpeg.