O7A CPU Load
The O7A plugins use 64 channel ambisonic tracks and consequently create high CPU load. You will probably need a powerful modern computer to make good use of them.
Why Does This Happen?
If you are familiar with our O3A plugins, you will almost certainly be aware that these use 16 channel tracks and busses, because they use third order ambisonics. In contrast, the O7A plugins use seventh order ambisonics and so 64 channels, to capture extra spatial detail.
When comparing CPU load, the best case situation is with very simple plugins like O7A Gain which do not do spatial processing, or plugins which only have an O7A input or output, but not both, for instance most decoders or upmixers. Here, the increase from 16 to 64 channels typically results in four times the work, and so a need for four times the CPU resources.
Many plugins with both an O7A input and an output will have roughly sixteen times the amount of work to do. Many of them also have internal calculations that become more complicated (64 times is not an uncommon ratio) although these are typically not significant in practice.
This isn't a disaster; our plugins are heavily optimised and do run fast for what they do. And some modern DAWs allow tracks to be "frozen", so it isn't necessary to calculate all of them at once. But, if you have a large project that needs seventh order throughout, you may need to think carefully about the hardware you are going to run it on.
So, Which Order To Use?
Generally we recommend third order (O3A) rather than seventh order (O7A) for practical ambisonics. The O7A plugins are primarily targeted at research applications, or studios with high-end modern hardware.
Don't say we didn't warn you!