The CF format, uses the CD ROM industry format of 150 kilobytes (KB) per second rating sytem as 1X. You can get CF cards at 1X, 16X up to 45X. The system processor must be able to handle these speeds. Try this method, taken from some other thread.
The tests were made according to Andrzej Wrotniak's method in the following way:
The camera was set in manual focus mode, with a short shutter time, and the flash disabled.
The memory card to be tested was selected.
The card was formatted in the camera.
The camera was set to save RAW pictures (gives an Olympus Raw Format (.orf) file with a size of 7.292 MB).
Pictures were taken and the write times were measured manually with a stopwatch, starting immediately after the exposure (shutter sound) and ending when the "busy" red light went off.
At least three measurements were made and the average time was calculated.