Canon EOS-1 DX Mark III Advanced User's Manual page 412

Caution
Maximum high-speed continuous shooting speed is available when shooting with a
fully charged battery at a 1/1000 sec. or faster shutter speed and maximum
aperture (which varies by lens*) at room temperature (23°C/73°F) with flicker
reduction disabled.
* For details, refer to the Canon website.
Using a Speedlite will decrease the maximum continuous shooting speed.
Setting the drive mode to <
mechanical sounds in Live View shooting or with [Enable:Mirror down w/
set for mirror lockup.
< > High-speed continuous shooting may be slower depending on the type of
power used, the ambient temperature, ISO speed, flicker reduction, shutter speed,
aperture value, subject conditions, brightness, type of lens, use of flash, shooting
settings, and other conditions.
With [ : Anti-flicker shoot.] set to [Enable] (
may decrease the maximum continuous shooting speed. Also, the continuous
shooting interval may become irregular and the release time lag may become
longer.
With AI Servo AF/Servo AF, the maximum continuous shooting speed may become
slower depending on the subject conditions and the lens used.
Maximum continuous shooting speed may be slower in low-light conditions.
Maximum continuous shooting speed is slower when the camera's internal
temperature is high and the drive mode icon is blinking, in order to prevent internal
damage to the camera. Even higher internal temperature from continued shooting
may cause significantly slower maximum continuous shooting speed, and the
camera may be temporarily unable to shoot until it cools down. If the drive mode
icon is blinking, allowing the camera to cool down with the power switch set to
< > is recommended.
Low temperatures may cause the battery itself to become very cold, and the drive
mode icon may blink, in which case maximum continuous shooting speed is lower.
There is a longer time lag than usual with <
shutter is released after you press the shutter button completely.
When internal memory becomes full during continuous shooting, the continuous
shooting speed may drop off because shooting will be temporarily disabled (
Note
Continuous shooting speed indicated for each drive mode is the speed under
default camera settings. You can set the continuous shooting speed for each drive
mode in [ 4: Continuous shooting speed] (
>, < >, or <
>, <
412
> has essentially no effect on
), shooting under flickering light
>, or <
).
]
> until the
).