OK, it’s not the speed that will take you to Pegasus galaxy in an instant, but it’s still quite impressive given the standard 600 MHz processor clock of the Nokia N900. There is no voltage tweak involved in this overclock, only a precompiled system kernel.
Currently, the N900 operates stably only up to 900 MHz. There has been a successful run even at 1GHz (hence my title) but it’s not for mass consumption yet.
For now, you can run your N900 CPU safely at 900 MHz and users report the sped benefit is enormous. Just don’t keep it running like that all the time since you may fry it.
Here is a video demonstrating how fast the N900 is running at 900 MHz: