Performance Dissection

As you have seen in the previous page, the Casio E-125 isn't much faster than its older brother, the E-115. Although the E-125 scored 16-20% faster than the E-115, most of this performance boost came from the higher clockspeed, rather than the larger data and instruction caches.

If you already have the E-115 and you are looking to buy the E-125 for a speed boost, I suggest you think twice since the speed boost isn't significant enough to warrant the cost of the E-125. But if you are thinking of overclocking the E-125 (read below), it might just be worth it...

Overclockability

As Casio chose to use the slowest speed grade of the Vr4122 processor, which is only 150MHz, many E-125 users are now overclocking the processor in order to gain a free speed boost as well as bring the E-125 closer to the iPAQ's level of performance.

Now, although NEC claims that the Vr4122 processor only has a maximum clockspeed of 180MHz, the Vr4122 can actually run up to 200MHz! In fact, the etchings on the PCB of the E-125 allows for a 200MHz setting. So, E-125 users have two clockspeed choices when attempting to overclock. They can try to overclock to 200MHz, failing which they can then fall back to 180MHz, which is practically every Vr4122 processor can attain.

There's a high rate of success reported in overclocking the E-125's processor to 200MHz. In fact, my E-125 successfully made the grade. Some users may report problems with the IR port after overclocking the E-125 to 200MHz. But since not everyone uses the IR port, you will have to decide if the extra 20MHz is worth the loss of the IR port, should you be unlucky enough to face this problem.

Unfortunately, overclocking the E-125 takes quite a bit of skill and daring as there's no software overclocking solution for it, unlike the iPAQ. You will have to open up the E-125 and close one or two bridges with a pencil or conductive pen on the PCB inside.

I followed the method posted by Fayle (our own overclocking guide coming up next!) and tested the E-125's performance at 180MHz and 200MHz. Subjectively, application loading was a lot faster and everything seem to zip by quickly. The E-125 was now noticeably faster than the E-115. Now, let's check out how well the E-125 performs after being overclocked to 180MHz and 200MHz!