Buffer 优化, 性能, 反应时间 ……
The buffer system of Samplitude is a little bit complex, but the user have the chance, to find an optimal configuration for his system and can change it very fast for different projects.
These are the important buffers:
- Most important: VIP buffer (Audio engine, mixer, effects - response time) - sub setting: Buffer numbers (usually not necessary to change, can help, if only some buffers run out - displayed in the status bar)
- ASIO buffer (monitoring with ASIO drivers)
- Trackspeed (HD cache with different settings for different numbers of tracks)
- VST plugin buffer (in the plugin settings dialog - plugin buffer size for VST/DSP cards - chance to find the best setting for a special DSP card)
VIP buffer:
The Mute/Solo/Fader/Automation response is VIP buffer related - lower the buffer, to something like 1000 or 2000 for a faster response.
Attention: A lower VIP buffer means a higher CPU load. If crackles of failures occur (see buffer display in the status bar) with this setting, increase the buffer numbers to 6 or 8.
ASIO buffer:
- I/O latency on live input signals
- VSTi response latency
- Playback and Recording stability (lost buffers with or without crackles)
Program priority in the combobox to highest ("Y" dialog/ASIO field). Not always the best choice (can add instability to the system - same as switching the Samplitude priority in the Windows task manager with a right click on the Sam7 Exe).
XP is recommendend for ASIO driver usage (set system to "optimized for background tasks" in the extended system options of XP)
Trackspeed HD cache settings:
The playback start delay can be influenced in the HD cache setting dialog (called trackspeed). If more than 32 tracks are in use, this means, the default value of 128 MB (!) cache size (=setting for +32 tracks) must be filled, before the playback starts. This results in a start delay of some seconds.
Lower the track values to 2/8/12/16 MB (or 2/8/12/24). This will increase the HD load, but a modern HD should be able to handle it.
Options: checkbox "preload cache" and "optimize scrubbing and play start" (slightly decrease HD performance). This will preload the cache after every stop and the playback will start faster. there is also a slider for best playback stability (=higher HD load).
Deactivation of "playback while recording" (record options - right click record button) can increase recording stability. Higher trackspeed settings (64/128 MB) can help, to avoid recording failures at higher HD loads.
CPU and HD load is displayed while playback in the lower left status bar.
By the way 42 tracks of 32 Bit are 84 tracks of 16 bit stereo and 168 tracks mono. Thats a lot, even for a powerful system. Impossible some years ago. Disc should be not fragmented and a second one to the OS disc (a second partition for audio files on the OS HD will not work - the head must jump between both partitions).
Room simulator buffer
The realtime room simulator introduces also a latency and slows down the mixer response at higher settings. The latency can be lowered in the advanced settings of the room simulator dialog. A buffer setting below 2024 disables the room simulator FFT EQ.
Other optimizations:
For a better performance on the PCI bus it磗 also a good idea, to disable the Matrox G450/G550 busmastering in the enhanced settings of the Windows display properties dialog. This will result in a more sluggish mouse, but the graphic card will not hook the bus for a longer time and your UAD + audio cards get a better timeframe to act. Also worth a try: a lower PCI bus latency in the mainboard BIOS (only for experienced users). Set it back, if it don磘 helps.
Go and get the latest single processor system with a stable board & power supply unit, fast HDs and 1 Gig RAM.
Recommended audio cards: RME/Lynx