The vast majority of Omnisphere Patches will play comfortably in your host, without over-stressing the computer’s CPU or memory. However, certain Patches employ more sophisticated effects or large numbers of streamed samples, and those may require special attention. If your system is not configured properly, playing those Patches might produce audio glitches.
This section describes actions you can take to minimize audio glitches and CPU overload. You should consider all of them, but note that some may not be appropriate for your individual circumstances. They are listed in the recommended order of implementation, starting with the easiest ones that have the biggest payoff. In some situations, you may need to perform several of these operations to remedy CPU overload issues.
Omnisphere allows up to 64 notes per part to be played simultaneously. You can adjust the maximum number of notes per Part with the Voices menu on the Main Page. High values can put tremendous demand on the CPU. Reducing “Voices” to 16, or 10, or even fewer is one of the first things you should try in order to significantly reduce CPU usage / overload.
Increase Host Buffer Size
If your performance is overloading the CPU, audio glitches can occur. One solution is to increase the host’s audio buffer size. Increasing the buffer size diminishes the CPU load and reduces audio glitches, but at the price of increased latency. A buffer size of 256 is usually a good compromise between good performance and acceptable latency, but a larger value may be needed if you need more CPU power. Each host has a unique process for setting the buffer size, so consult your host’s documentation for details. For example, in the Omnisphere Standalone, the buffer size menu is on the Settings page:
: In some programs like MainStage, the total resulting latency is a combination of I/O Buffer Size and the program’s Driver Latency Settings.
Move STEAM data to a faster drive
The performance of Omnisphere depends on the speed of the drive on which the STEAM data is stored. The fastest drives are Solid State Drives (SSD) and are preferable to HD drives which use a spinning platter.
In addition, it is strongly recommended that the STEAM data be located on an internal drive, using an internal bus such as PCIe or SATA. If you must place STEAM on an external drive, we recommend a fast connection such as Thunderbolt or USB (v3.2 and up recommended). If using USB 3.x, make sure the computer supports the USB 3.x interface.
Most modern laptops have high-performance internal Solid State Drives (SSD), which usually have a faster transfer rate than using external drives.
Some computers allow you to add RAM after purchase and some do not, but to aid in your computer’s performance, the more (and faster) RAM, the better.
Multi-Core Processor Optimization
Omnisphere and all STEAM-based instruments utilize resources from one processor core per instance. Most, if not all, modern computers rely on multi-core processors. Spreading Patches over several instances in a DAW helps maximize performance.
Check Host Sample Rate
Omnisphere has been designed for optimal playback at 44.1k or 48k sample rate. If a host’s sample rate is higher than this (88.2k, 96k, 192k, etc) it can significantly reduce Omnisphere’s performance without any real sonic benefit. In fact, certain Patches may not play correctly at higher sample rates. We recommend keeping your host’s sample rate at 44.1KHz or 48KHz for the optimal experience with Omnisphere. Each host has a unique process for setting the sample rate, so consult your host’s documentation for details—typically it is found in the host’s preferences.
Terminate Other Applications
When performing live, it is better to terminate all non-essential applications. Each application consumes CPU power and RAM and indirectly reduces the capabilities of the host. Close as many applications as you can, including browsers, mail, etc. Your computer may also be running several “background” applications, such as disk backup utilities and anti-virus utilities. These background applications also consume CPU and RAM. You can determine if your computer is running any background applications by using the Activity Monitor (Mac) or Task Manager (Windows). Whenever you can, disable or terminate them when running your host.
Disable Operating System Power and Screen Optimization
Background processes like power optimization and screen savers can also result is a smaller amount of CPU resources allocated to the host. On laptops, it is recommended to disable the power-saving features that put the computer to sleep or turn off the display when not in use for a period of time. Any other kind of Low Power Modes should be disabled as well.
(ManualNote) Keep in mind that using your laptop while connected to power maximizes CPU performance.
Most patches in Omnisphere load with their own set effects. If you are loading multiple patches in a Multi, each patch might have its own dedicated reverb, delay, etc., which can tax your computer’s CPU. In order to minimize performance issues, whenever possible, disable per-part effects and share them via the MULTI FX Rack. This requires a certain amount of setup time and knowledge, but the advantages of having your effects set up to work efficiently can drastically reduce the amount of power Omnisphere demands of your CPU.
Here is an example scenario of sharing a reverb across parts:
1. Load the patch “Drop Springs” in Part 1 and “Adagio Transparent Strings Bright” in Part 2.
2. In Part 1, explore the FX Racks of “Drop Springs.” In the AUX FX rack, you’ll find two effects: “Analog Chorus” (used to add modulation before the reverb) and “Pro-Verb.” Disable both units.
3. Since the Aux FX rack now has no engaged effects, bring the “Aux Return” slider all the way down. This prevents the dry signal’s level from increasing since it’s still being sent to the AUX FX rack from the Common rack.
4. Now let’s work on Part 2 by looking at the FX Racks in “Adagio Transparent Strings Bright.” In this case, the AUX FX rack is empty, but there is a “Pro-Verb” effect loaded in the COMMON rack. Disable it. At this point, none of the patches have reverb.
5. To add a shared reverb to both sounds, go to the Mixer page and increase the “Aux 1” knobs for Parts 1 and 2. Since the default Multi loads with a CPU-efficient FX reverb in the MULTI FX AUX 1 rack, using the “Aux 1” sends is a quick way to add reverb to any part.
6. Go to the MULTI FX AUX 1 rack and customize the reverb settings to work well with both sounds.
Keep in mind that depending on which patches you are using, sharing effects can alter the sounds in unexpected ways. Based on your CPU’s power, you will need to decide which effects to share and which to leave enabled on each part.
Enable Sample Thinning
Depending on your system, when Omnisphere is using sounds that contain a large number of samples, you might encounter CPU overload or streaming issues. This is most likely to happen when multiple large sample-based Patches have been loaded, or when using certain larger Keyscape sounds. In these situations, the first step is to enable THINNING by turning on the “Lite Version” button at the bottom of the Full Patch Browser. This will reload the Patch with a reduced number of samples.
NOTE: Thinning only helps for sample-based Patches: it has no effect on synth-based ones.
Detailed THINNING options are available from the Patch Browser by clicking the zoom icon next to “Lite Version” in the footer.
An alternative way to thin sample-based Patches is with the SAMPLE THINNING button in the Soundsource Zoom page. This method allows you to individually optimize the Soundsource in each Layer.
Alternatively, if you are using Keyscape Patches in Omnisphere, you can achieve the same optimization by simply using the THINNING button on the Custom Control’s Settings Page. The thinned versions of the Patches have been optimized to maintain the highest possible quality for each sound. The THINNING button can also be locked, ensuring that all Keyscape Patches load the thinned version automatically.
Need more help with this?
Spectrasonics Customer Support