There's a main crystal of 31 MHz on the SE/30 board. It gives the processors and other chips to run and 1/2 its speed or about 16MHz. It is this half speed which much of the SE/30 processing circuits uses. To get your SE/30 to run at 33MHZ, you need to replace that crystal with a 66MHz crystal. Like wise if you want to run your SE/30 at 25 or 20 MHz, you need to run a crystal a double that speed- 50 or 40 MHz respectfully.

Or so goes the theory. In this case the theory is correct if this were a "Perfect World."

But the other chips on the mother board does not run at anything faster than 16MHz. And the video is synchronized at 16MHz - change that and you lose the video. The same with the other I/O (Serial, ADB, SCSi, etc). And on top of that you need to get faster RAM to run at the higher speed.

So even if you can get your SE/30's 68030 CPU and 68882 MPU to run at a faster speed, you loose everything else.

If you want a faster SE/30, you need to get an accelerator to put on it's PDS Slot. Only then can you run at a higher speed by having a "separate Mac" inside the SE/30 and run all your software for the SE/30's 68030, and then give that processed information back to the SE/30's 68030 so it can display on the video, print it to the printer and save it on the floppy/SCSI hard drive.

There are many accelerators for the SE/30, which one you want to need to research and go ind it.