Universal asio driver For wdm audio Instruction Manual

5. Latency Compensation
Since ASIO4ALL does not have sufficient knowledge of the underlying hardware/driver architecture, it 
can only guess the actual latencies involved.
With these sliders you can compensate for the latencies unknown to ASIO4ALL such that recordings in 
your sequencer Software are properly aligned with the rest.
Note: In multi-device-setups the largest respective value of all devices will be used. Therefore, if
Note: In multi-device-setups the largest respective value of all devices will be used. Therefore, if
different devices have different inherent latencies, audio placement will not be accurate for some devices!
different devices have different inherent latencies, audio placement will not be accurate for some devices!
Illustration 2: Advanced Control Panel View

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6. Hardware Buffer on/off 
Note: For WaveRT drivers (Vista), this box is labeled “
Note: For WaveRT drivers (Vista), this box is labeled “
Allow Pull Mode (WaveRT)
Allow Pull Mode (WaveRT)
” instead!
” instead!
Enables the hardware buffer for the highlighted device. This only works for so called “WavePCI” 
miniports, as other types of WDM drivers do not usually allow direct access to the hardware buffer.
Adjustment for best hardware buffer performance involves the “ASIO Buffer Size” slider and the “Buffer 
Offset” slider (see below). Hardware buffering works best for rather small ASIO buffer sizes. Try 
something between 128 and 256 samples as a starter!
The biggest advantage of using the hardware buffer is that this method uses a lot less CPU. In addition, it 
may be possible to decrease latencies even further.
In multi-device-setups, it is possible to mix Hardware-buffered devices with devices that are not. This, 
however, is not particularly recommended!
If hardware buffering is not supported by a particular audio device, there will be an additional latency of a 
couple hundred milliseconds, which is clearly audible.
“Allow Pull Mode (WaveRT)”
There are two basic access methods for a WaveRT device, “pull-mode” (also called “event-mode”) and 
“push-mode” (also called “polling mode”). “push-mode” is thought to be supported by all WaveRT 
drivers and (Vista) OS platforms, whereas “pull-mode” wasn't even officially documented by Microsoft 
until almost one year after Vista went RTM. As a consequence, “pull-mode” is still broken in a number 
of instances.
If this box is left unchecked, ASIO4ALL will never use “pull-mode”, otherwise it will use it whenever 
possible. If it works, “pull-mode” provides tighter timing and is generally thought to be technically better 
than “push-mode”.
Note: The old ASIO4ALL 2.8 behavior for this option was as if 
Note: The old ASIO4ALL 2.8 behavior for this option was as if