Overclocking B3

Overclocking the B3

Disclaimer: You do this entirely on your on behalf. Excito is not liable for any damages you, your B3 or anything or anyone else takes in that process as far as legislation permits. If you are not familiar with soldering at all, modifying the B3s hardware is discouraged! Warranty may be lost and the overall lifetime of the B3 will possibly shorten.

Requirements:

•  A good reliable regulated soldering iron with a very tiny head (preferably a double headed)
•  Tweezers (if you do not have a doubleheaded soldering iron)
•  Desoldering paper
•  Solder
•  Magnifying glass (or very good eyes)
•  Tranquil hands
•  A lamp

Soldering

The maximum clock speed of the B3 is a matter of a hardware setting, therefore it is required to move some resistors around on the board. Make sure to place the resistorsexactly as shown. Warning! Any error here may render the board disfunctional, or lead to unspecified behaviour - this includes damage to the hardware and potential dataloss. ===

The picture shows the resistors in their final position which I marked as green. The prior (default) position of these are marked as red rectangles. (Note that some resistors look different because they got turned upside down in the moving process, that does not matter).

Soldering tips for those with a single headed one:
Flood the area with solder and drag the resistor through the liquid solder with your tweezers. Afterwards remove the overrun solder with the desoldering paper.

Results

If the whole process went well, your B3 will startup just fine as it did before (no software modifications are required).

To check if the CPU has been properly overclocked, do a
[code]cat /proc/cpuinfo | grep "BogoMIPS"[/code]. The default setup shows [code]1196.85[/code]
the modified setup [code]1495.85[/code] which is equivalent to the clock increment from 1.2GHz to 1.5GHz.

L2 cache clock gets increased from 400 to 500MHz.

The memory frequency gets adjusted to resemble a defined combination of processor and memory speed according to the datasheet. So it actually gets decreased from the 400 to 375MHz.

A quick openssl test (software backend) shows a performance advantage of 20-25% which is (almost) proportional to the clock increment. Power measurements do not show any notable increase in powerrequirements (measured with default setup in idle, no networks connected, no USB connected, no SATA connected, wifiless model).

If you have any testsuites running on your B3 that you would like to see run on the local overclocked B3, do not hesitate to drop a request in the forums.