[Владимир Матвийчук]

Читаю мануал на FF400 http://www.rme-audio.de/download/fface400_e.pdf

Buffer Size (Latency)
Windows: This option found in the Settings dialog defines the size of the buffers for the audio
data used in ASIO and WDM (see chapter 9).
Mac OS X: The buffer size is defined within the application. Only some do not offer any setting.
For example iTunes is fixed to 512 samples.
General: A setting of 64 samples at 44.1 kHz causes a latency of 1.5 ms, for record and playback
each. But when performing a digital loopback test no latency/offset can be detected. The
reason is that the software naturally knows the size of the buffers, therefore is able to position
the newly recorded data at a place equalling a latency-free system.
AD/DA Offset under ASIO and OS X: ASIO (Windows) and Core Audio (Mac OS X) allow for the
signalling of an offset value to correct buffer independent delays, like AD- and DA-conversion or
the Safety Buffer described below. An analog loopback test will then show no offset, because
the application shifts the recorded data accordingly. Because in real world operation analog
record and playback is unavoidable, the drivers include an offset value matching the Fireface's
converter delays.
User's Guide Fireface 400 © RME 87
Therefore, in a digital loopback test a negative offset of about 3 ms occurs. This is no real
problem, because this way of working is more than seldom, and usually the offset can be compensated
manually within the application. Additionally, keep in mind that even when using the
digital I/Os usually at some place an AD- and DA-conversion is involved (no sound without...).
Note: Cubase and Nuendo display the latency values signalled from the driver separately for
record and playback. While with our former cards these values equalled exactly the buffer size
(for example 3 ms at 128 samples), the Fireface displays an additional millisecond – the time
needed for the AD/DA-conversion. Playback even shows another millisecond added – see
Safety Buffer.

Может, я что-то пропустил; где написано, что на Маке задержки меньше в 3-4 раза?