QLab 4 is a Mac-only program. It requires Mac OS 10.10 or higher, and will work on any Mac that can run 10.10.
Because of QLab's great flexibility and the varied scenarios in which it is used, it can be difficult to determine ahead of time how much computer power a given QLab workspace will require. What follows is a discussion of general concepts surrounding processor, GPU, RAM, and hard disk use for QLab. Please take this information not as a firm set of instructions about what to do, but rather as a set of recommendations about what to consider.
QLab is not supported on "hackintoshes" at all. Please do yourself a big favor, and just keep away from those. QLab is likewise not supported in a virtual machine environment.
The more work QLab needs to do, the happier it will be with a more powerful processor. Large numbers of audio or video cues playing back simultaneously, for example, benefit from an i7 or Xeon processor which have better handling of multithreading tasks than i5 or older processors. Most new Macs have i5 processors by default, but can be configured with i7 processors instead. Mac Pros use Xeon processors.
For audio-only users, GPU considerations are fairly negligible. For video folks, what you need depends entirely upon what you're trying to accomplish. Mac Minis, for example, can drive two HD displays simultaneously; one for your operator and one for your projector. Since those two displays share a single integrated GPU, you can improve overall performance by lowering the resolution on your operator's display; the computer will be doing less work for the operator's display, which means more power is available for video crunching. If you use a Mac Pro "cheese grater" tower (that is, pre-2014), dedicating one modest video card for your operator display and one higher-end card for each projector, or one card per two projectors, is a good strategy. For the newer "trash can" Mac Pro, all graphics connections are on the same GPU, which is much more powerful than its predecessors. Testing is, as always, important.
For those seeking best-possible video performance, a Mac with a discreet GPU is the way to go. The Mac Pro, some MacBook Pro models, and some iMac models are the only Macs which have discreet GPUs. The 5K iMac is the one model we specifically recommend against despite its powerful GPU, because most of the power of that GPU is dedicated to driving the internal display.
For Macs with an integrated GPU, which is all Mac Minis, the MacBook, all MacBook Airs, most iMac models, and most MacBook Pro models, the GPU uses a portion of system RAM as VRAM. The size of this portion is based on the total amount of system RAM installed, so the more RAM you have, the more of it will be used for VRAM. While we don't recommend using a Mac with an integrated GPU for video-intensive shows, if you do use such a Mac we strongly encourage you to install the maximum possible amount of RAM.
Loading and playing cues uses RAM, so the more audio or video that needs to be loaded at any given moment, the higher the RAM requirement will be. 4 GB is a nice minimum amount of RAM to work with, and is conveniently the minimum amount of RAM offered with most new Macs. As with processing power, complex shows can benefit from (and may require) more RAM. QLab 4 is able to address as much RAM as your Mac can provide.
QLab is happiest with a solid state drive (SSD) because they are, to put it plainly, really really fast. The more data you're pulling off your disk and pushing out of your speakers or projectors, the more an SSD is a good idea. We do not recommend using a 5400 RPM drive for anything other than the simplest shows.
Apple's Fusion Drive, though it technically includes an SSD, is not recommended for use on a show computer under any circumstances, as the user has no control over which data is stored on the SSD portion and which is stored on the hard disk, nor any say in when the Mac decides to shuffle data between the two.
The best way to output video from QLab is to use the built-in video connections on your Mac (including PCI cards on "cheese-grater" Mac Pros.) Using a Pro Video or Pro Bundle license, you can also output video directly to Blackmagic Design's DeckLink, Intensity, and UltraStudio devices, although this comes at the cost of a reduction in CPU performance and an increase in latency.
We do not recommend, nor do we support, video output via DisplayLink USB-connected monitors and video adapters. While these devices can work, they are not GPU accelerated and their drivers do not have a solid history. Your mileage may vary, but Figure 53's position is to avoid using these devices entirely.
If you have specific questions about hardware requirements, please email the support team, and tell us about your show. We will be happy to advise you.