How to clock your 505FX from 266MHz to 300MHz

Some time ago I found an interesting page on overclocking the VAIO. Especially interesting was the description for the Japanese PCG-505S. I know, it's Japanese, but if you use the Babelfish Altavista translation service, you get a translation that's sufficient to understand.

In any case, the clock selection section of the 505S mainboard looked exactly like my 505FX, so I thought, what the heck, give it a try. I disassembled the 505 again, and tried what the author suggested:

• locate the area on the top of the mainboard, left of the CPU.
• remove chip jumper JR1
• install a surface mount resistor of 2.2k in location R4

I did not have a 2.2k resistor handy and used a 4.7k instead, without a problem. As you can see in the picture though, the 0805 resistor is too big, and it would be better to use a 0603 size resistor, if you can get your hands on such a beast. I planned to have that 4.7k 0805 in there as a temporary solution only, until I find a 0603, and then make a nicer looking soldering job. But this one works, so I really don't see the need.

If you power up the VAIO again and hit F2 quickly, the BIOS will tell you you're running at 300MHz now instead of 266MHz. It's only 13% increase of speed, and my VAIO has been running at this speed now for months without any problem. Now it is running at the same speed as its successor, the PCG-300E (European model).

If you decide to attempt this modification, be sure you know what you're doing! You should have experience with soldering surface mount parts.

This procedure is meant as a guideline. It is based on the European PCG-505FX I own, and other models may vary. Also, overclocking lowers the safety margin and some CPUs may overheat. Anything you break or damage you do at your own risk!

Sony and the VAIO logo are registered trademarks of Sony Corp.