Processor selection fails in two different ways: total pixel capacity (the wall simply does not fit) and port capacity (the wall fits on paper but cannot be wired sensibly). Both numbers are on the datasheet, both scale with refresh rate and bit depth, and both need headroom. This is how to read them.
Every controller datasheet gives a total pixel capacity — 3.9 million for a NovaStar VX600, 6.5 million for a VX1000, 8.8 million for an MCTRL4K, 10.4 million for a CX UHD Jr — and a per-port figure that limits how many pixels each physical output can feed. A five-megapixel wall fits a VX1000’s total, but whether it wires cleanly depends on how those pixels divide across ports.
The standard per-port figure for a gigabit port is 650,000 pixels at 60 Hz and 8-bit (NovaStar’s published rating; Brompton rates 525,000). Working crews load ports to about 80% of that, both for headroom and because walls rarely divide into perfectly full ports.
The published figures assume 60 Hz and 8-bit colour. Run 10-bit or 12-bit and NovaStar’s own datasheets halve the port figure to 325,000 pixels. Push refresh beyond 60 Hz and capacity scales down proportionally. A wall that fits comfortably at 60 Hz 8-bit can need twice the ports — or a bigger processor — the moment the camera department asks for high refresh or the colourist asks for 10-bit.
Ask about refresh and bit depth before sizing the processor, not after. It is the single most common way a processor that "fits" stops fitting.
Looped A+B redundancy feeds every run from two ports, halving the usable port count per processor. It is standard practice on broadcast and critical installs, and much less common in general rental, where a spare cable run and a fast crew are the usual insurance. Decide redundancy first; it can double the processing on the truck.
Older sending-card architectures (Linsn-class) render the full row width of the canvas on every output. Wiring half a row still spends whole-row bandwidth, so on a wide wall some configurations are impossible even though the physical panel count per port looks fine. Modern controllers map regions exactly. If the shop runs legacy cards, check the wall width against the card’s row budget before promising a single-processor build.
At the top end, processing is a fleet, not a box: chassis like Brompton’s SX40 (9 megapixels, with 10G trunks breaking out to gigabit legs) or NovaStar’s H-series (two to ten output-card slots depending on chassis, 10.4 megapixels per card, up to 104 megapixels in an H15) get built to the job from the cards the shop owns. The planning question becomes "how many cards do we own and where are they this weekend" — which is an inventory problem as much as an engineering one.
RigPlan does this arithmetic for you. Enter the wall once and it derives panels and spares, rigging from your own stock, circuits, the data wiring plan and the full pack list — free, no sign-up.
Open the calculatorA gigabit port carries about 650,000 pixels at 60 Hz 8-bit on NovaStar’s published rating (Brompton rates 525,000), and half that at 10- or 12-bit. Crews load ports to roughly 80% for headroom.
A full 4K canvas is about 8.8 megapixels, which is exactly an MCTRL4K at 60 Hz 8-bit and beyond a VX1000 (6.5 MP). At 10-bit or high refresh the same wall needs the next tier up or multiple units.
Yes — looped A+B redundancy feeds every run twice, halving each processor’s usable ports. A wall that needs 12 runs needs 24 ports with redundancy, before any headroom.