Taken from www.Hauptwerk.com
Audio/sound interfaces. In principle, any audio or sound interface which is supported by the manufacturer on your operating system and hardware, and has good drivers should work. Mac OS X has high-performance, low latency audio and MIDI support built in, and there is usually less dependence on driver quality than on the PC, so less risk of driver/compatibility problems. On PC platforms either ASIO or DirectSound drivers can be used, with good quality native ASIO drivers usually giving by far the best performance.
Any audio interface you use must natively support the sample rates used by the organs you wish to load into Hauptwerk (typically 44.1 kHz, 48 kHz and 96 kHz). Note that the default built-in sound output found on many computers, including Apple Macs, only supports 44.1 kHz and so cannot be used with sample sets requiring other sample rates, such as 48 kHz. The sound quality from most computers' built-in outputs is also not usually especially high.
Since it is impossible for us to test with all products, and some interfaces do have problems with some types of drivers on some platforms, we would either recommend using one of the following interfaces, which we test with and fully support, or we would recommend testing an evaluation version of Hauptwerk with your system before purchasing a licence.
On Mac OS X 10.6 'Snow Leopard' our recommendations are:
On Mac OS X 10.5 'Leopard' our recommendations are:
On Mac OS X 10.4 'Tiger' our recommendations are:
On 32-bit editions of Windows Vista our recommendations are:
On 64-bit editions of Windows Vista our recommendations are:
On 32-bit editions of Windows XP our recommendations are:
On 64-bit Windows XP x64 our recommendations are:
(1) We found that performance of the onboard MIDI ports was sluggish with the current Echo drivers for 64-bit Windows (only). Hence we would currently recommend using a separate MIDI interface with the Echo Audiofire interfaces on 64-bit Windows platforms.
(2) The current M-Audio 64-bit ASIO drivers only work with 32-bit Hauptwerk, limiting usable memory to 4 GB.
(3) The current drivers for this interface are beta and/or not fully supported by the manufacturer. We found them to work but you might not be able get support from the manufacturer if you have a problem.
On both Mac and Windows platforms, the Echo, MOTU and M-Audio (1010/1010LT and 2496 only) drivers allow several units to be connected to the computer at the same time to give more outputs.
The Echo, MOTU, Focusrite, PreSonus, RME, and M-Audio websites have their full specifications.
Professional or semi-professional audio interfaces with high-quality DACs and drivers are strongly recommended above consumer-level sound cards. Apart from audio quality, the quality of the audio interface and its drivers can have an enormous effect on performance, as much as halving or doubling the number of pipes that your computer will be able to sound simultaneously, and determining the delay between pressing a key and hearing the sound ('latency').
Unless specifically advised to do otherwise, it is usually best to ensure that the latest versions of the manufacturers' drivers and firmware are installed.
Please note that the Creative Audigy 2 interfaces, commonly-used in PCs, do have ASIO drivers, but those drivers do not fully support multiple sample rates, and thus cannot be used with some Hauptwerk sample sets in ASIO mode. However, the Creative Audigy 2 interfaces do have fairly low-latency DirectSound drivers on both 32 and 64-bit editions of Windows. In general, we do not recommend the Creative interfaces for use with Hauptwerk because of their restrictive ASIO drivers, although they can instead be used with DirectSound drivers.
Notes about audio interface compatibility with 64-bit Windows: If you intend to use Hauptwerk on 64-bit Windows, please check the website of your intended audio interface's manufacturer for genuine 64-bit ASIO driver support, and, if possible, test the interface with Hauptwerk first, since some 64-bit ASIO drivers do not yet fully work with native 64-bit software.
(content taken from www.hauptwerk.com)