User's Guide
DIGI96 © RME
14
Please note that the given latency describes only one way. The complete path through the
computer (record plus playback, monitoring) gives double values.
The mode 6 ms often causes crackling and drop outs when used with harddisk based recording,
but operates flawlessly when using realtime Synthesizers or pure signal processing (Live Input
mode). 11 ms are only recommended in 2 channel operation. Else we STRONGLY recommend
to use 46 ms to achieve the highest reliability and security in operation. The 24 bit modes
should only be used when really needed, as they not only halve the buffer size (see above), but
also produce a higher system load and less reliable system behaviour.
12.3 Performance
The 'Audio Performance' settings are especially important.
A very common problem is insufficient hard disk perfor-
mance. If the first track is missing while recording multiple
tracks, or the error message ‘Audio: Record Error’ appears,
the disk sub-system is too slow i.e. it is unable to write the
audio data to the disk quickly enough. The problem can
almost always be remedied by changing ‘Disk Block Buffer
Size’ from the default 64kB to 256kB. Please note that the-
se parameters are only updated after clicking on ‘Apply’.
The heyday of (expensive) SCSI hard disks in high-speed audio workstations is over. Today’s
cheap high-capacity EIDE disks allow continuous transfer rates of well over 5 MB per second.
In practical terms, this is more than enough to playback more than 30 tracks recorded onto
hard disk using Cubase and the DIGI96 series!
Working at 96 kHz and 24 bit requires a very fast computer. We recommend at least a G3/400
MHz machine. The reason for this is the very small buffer size in our ASIO driver at this set-
ting. The value 23 ms/32 bit is calculated on 44.1 kHz as base. This means at 96 kHz the ef-
fective latency is only 11 ms! At such a low latency the Mac has to be optimized for Low Laten-
cy operation, otherwise random click noises will occur. We are currently preparing a Tech Info
on this topic, which will be released on our website as soon as it is finished.
12.4 Known problems
In case the used computer has no sufficient CPU-power and/or sufficient PCI-bus transfer ra-
tes, then drop outs, crackling and noise will appear. We also recommend to deactivate all Plu-
gIns to verify that these are not the reason for such effects.
Another typical source of trouble is wrong synchronization. ASIO does not support asynchro-
nous operation. This means input and output signal must not only have the same sample fre-
quency, but must also be 'in sync' for error-free Full Duplex operation.
See chapter 12.2 for problems with too low latency, caused by 24 bit or 96 kHz operation.
