LED module datasheet markings: what P5, SMD1921, 1/8 scan and HUB75 mean
A LED module datasheet lists ten or fifteen lines of numbers and abbreviations one under the other: P5, SMD1921, 320 x 160 x 18 mm, 1/8 scan, IP65, HUB75, 4.5-5 V, 14 bit, 271 W/m². These are not marketing labels but technical parameters, and once you can read them you can decide in minutes whether a module suits your site.
How to read a full module designation
A module's full designation typically looks like this: P5 outdoor SMD1921, 320 x 160 x 18 mm, 64 x 32 px, 1/8 scan, IP65, HUB75, 4.5-5 V. In order: P5 is the pixel pitch in millimetres, SMD1921 is the size of the LED chip package, 320 x 160 x 18 mm is the physical size of the panel including thickness, 64 x 32 px is the resolution that follows from it, 1/8 scan is the drive mode, IP65 is the dust and water protection, HUB75 is the controller connector, and 4.5-5 V is the supply voltage. Eight figures, and all eight affect how the finished wall will look and what it will cost to run. Most misunderstandings arise because the buyer looks only at the first, the P value, and leaves the other seven to the supplier. We work through them in the order below, in the same logic in which they are worth asking about when requesting a quotation.
P value: the pixel pitch in millimetres
The number after the letter P is the distance in millimetres between the centres of two adjacent pixels. P5 is therefore a 5 mm grid and P2.5 a 2.5 mm one. A smaller number means a denser LED layout: more pixels fit on the same surface, so the image does not break up into separate points of light even at closer range - in exchange for more LEDs, more driver ICs and more data to move. The P value is not always a round number: the actual pixel pitch of our outdoor P3 module is 3.076 mm, because 104 pixels fit evenly across the 320 mm module width (320 ÷ 104 = 3.0769). If you see a fractional value on a datasheet, that is not an error but the result of dividing the module size by the pixel count. The full range of pitches can be reviewed on our LED modules product page.
Viewing distance: how pitch becomes metres. Physical minimum and comfortable band - two separate numbers
Sooner or later the pixel pitch has to be translated into viewing distance, and for that we use two separate numbers that are worth not confusing. The first is the physical lower limit: the minimum recommended distance on our module datasheets is, in metres, roughly the pixel pitch in millimetres - our outdoor P2.5 module datasheet, for example, gives ≥2.5 metres as the optimum viewing distance. From there the image comes together and the pixel grid ceases to be perceptible. The second is the comfortable band for sustained viewing, and that is the design value: 2.5-3 times the pitch in millimetres, as our article on pixel pitch also gives. In figures, that means a lower limit of 4 metres and a comfortable band of 10-12 metres for a P4 surface, 10 metres and 25-30 metres for a P10, and 1.9 metres and roughly 4.7-5.6 metres for a P1.86. Always design with the comfortable band; the minimum only tells you how close you can go, not where it will be good to look from. If a quotation gives a single number under 'recommended viewing distance', ask which of the two they used - the difference is two and a half times.
320 x 160 mm: the module size that is almost the same on every type
The overwhelming majority of LED modules today are built on a 320 x 160 mm base board, whether it is a P1.25 fine-pitch or a P10 outdoor module; the great majority of our own module range is at this size, with thicknesses between 17 and 18.5 mm. There are exceptions: on the rarer P8 pitch, our own module database shows a 256 x 128 mm base board, so always read the module size from the datasheet rather than assuming it. The uniform size is a practical advantage because the support structure, the cabinet division and the sizing of the surface can all be designed to the same grid - the width and height of the wall will always be a whole multiple of the module size. A 320 x 160 mm module has an area of 0.0512 m², so 19.5 modules are needed per square metre. The modules weigh 422-477 g each, which means the module layer alone comes to 8.2-9.3 kg per square metre - and to that you still have to add the frame, the power supply, the receiving card and the cabling. This is the figure that must never be guessed at when designing the support structure: the structural load of the wall does not begin at the weight of the modules, it ends there.
Pixels per square metre: the formula that turns a marking into resolution
Pixels per square metre come from a single formula: (1000 ÷ pixel pitch in mm)². This is the number that most strongly determines a module's price, its consumption and its image quality. Some specific values from our own datasheets: 10,000 at P10, 40,000 at P5, 62,500 at P4, 105,625 at P3, 160,000 at P2.5, 250,000 at P2, 288,906 at P1.86 and 640,000 pixels/m² at P1.25. A P1.25 module therefore has sixty-four times as many pixels per square metre as a P10, and roughly that many more LED packages too. The same formula gives the module's own resolution: divide the 320 mm width by the pixel pitch. At P5, 320 ÷ 5 = 64 columns and 160 ÷ 5 = 32 rows, that is, 64 x 32 pixels. If an advertised resolution does not match that division, then either the module size or the P value is not true.
SMD1010, SMD1515, SMD1921 - the size of the LED package in tenths of a millimetre
The four digits after SMD give the footprint of the LED package in tenths of a millimetre: the first two are the length, the second two the width. SMD1010 is therefore a 1.0 x 1.0 mm package, SMD1415 is 1.4 x 1.5 mm, SMD1515 is 1.5 x 1.5 mm, and SMD1921 is 1.9 x 2.1 mm. The consequence is very simple: the package cannot be larger than the pixel pitch. That is why our P1.25 module uses SMD1010, the P2 and P1.86 use SMD1515, and the outdoor P4 and P5 use SMD1921 - the last of which would not physically fit into a 1.25 mm grid. A larger package holds a larger chip and more material, which is why it gives greater brightness: this is partly why our outdoor modules reach ≥4,200-4,500 cd/m², while the fine-pitch indoor GOB panel datasheets show ≥400-500 cd/m².
SMD, GOB, COB, DIP: the type of packaging, not its size
Alongside the size, the type of packaging also appears in the marking, and it is one of four abbreviations. SMD is the surface-mounted LED that integrates three colours (red, green, blue) into one package - this is the default today, and the 1R1G1B marking describes exactly that: one red, one green and one blue chip per pixel. With GOB (glue on board), the finished SMD module is potted in clear resin, so the surface becomes resistant to impact, dust and moisture and the LEDs cannot be knocked off - which is why we use it on fine-pitch indoor panels that are within arm's reach. With COB the chips go directly onto the substrate, while DIP is the traditional lamp-shaped LED with legs, seen today mainly on coarse pitches and single-colour signs. A detailed comparison of SMD, COB and DIP is in a separate article; GOB is not a separate LED type but a protective layer on a finished SMD module.
Scan rate: the marking that explains the brightness
A value in the form 1/8, 1/16, 1/40 or 1/64 is the scan rate. It states what fraction of the module's rows is lit at any given instant: an eighth of the rows at 1/8 scan, a sixty-fourth at 1/64. The eye sees this as a continuous image, because the switching is faster than we can perceive - but it shows up precisely in the brightness. That is why the two figures are so closely linked: our P5 outdoor module with a 1/8 scan gives ≥4,500 cd/m², while the P2.5 indoor GOB module with a 1/64 scan gives ≥400 cd/m². Our indoor modules scan between 1/32 and 1/64, our outdoor ones between 1/8 and 1/16. A practical rule: if a module advertised as outdoor shows a 1/32 or denser scan on its datasheet alongside low brightness, it is probably an indoor panel in an outdoor housing. Static (1/1) drive gives the greatest brightness but needs more driver ICs, so it costs more.
The datasheet values from our module product pages, side by side
The table below sets the datasheet values of the modules in our own range side by side, so you can see how the markings move together. Two relationships can be read from it at once. First: as the pixel pitch falls, the pixel count per square metre rises and the scan rate becomes denser too. Second: the brightness difference between indoor and outdoor modules is not one of degree but of magnitude - the multiplier between ≥400 cd/m² and ≥4,500 cd/m² is more than eleven. Those are the two figures that would prevent most bad purchases if the buyer looked at them. The viewing distance column shows the comfortable band, that is, 2.5-3 times the pitch in millimetres; the physical lower limit is far closer, at the number of metres equal to the pitch in millimetres. In the consumption column you will find two numbers: the average, with which the electricity bill can be estimated, and the peak, to which the power supply and the feed have to be sized. The table works with the main builds; there can be variants of the same pitch with different settings - our high-brightness version of the P2.5 indoor GOB module, for instance, works with a 1/32 scan and ≥500 cd/m², at 163 W/m² average and 488 W/m² peak consumption.
IP65 'from the front' or IP65 everywhere? The ingress protection trap
The two digits of the IP marking give protection against solid objects (first digit) and water (second digit). IP65 means dust-tight sealing and protection against water jets from any direction. The trap is that many datasheets do not say plain IP65 but 'IP65 (front)' - meaning the front of the module is sealed while the rear is not. That is not a fault or a trick: such modules are designed for a cabinet or a sealed box, where the structure protects the rear. Trouble comes when someone mounts them outdoors, free-standing, with no frame and no rear closure. Our outdoor modules operate between -20 and +60 °C and our indoor ones between -20 and +40 °C: behind a sunlit facade in summer, the upper limit for an indoor module can realistically be exceeded.
HUB75, HUB320 and what '2 x HUB75' means
The HUB marking gives the standard of the ribbon-cable connector between the module and the controller or receiving card. HUB75 is the most widespread, full-colour interface, physically a 16-pin (2 x 8) ribbon-cable connector - most of our modules use it. If a datasheet says 'HUB75 (2 pcs)', as on our outdoor P3, P4 and P5 modules, it means the panel receives the image over two data channels, because the bandwidth of one would not be enough. On very fine pitches, a dedicated, denser connector appears: our P1.25 module has a HUB320 interface. This marking matters in practice because the controller has to know the HUB type, the scan mode and the chipset - without them the module will not start, or will light with the wrong colour order. So never buy a module without a matched controller and power supply.
Front or rear service: the marking that decides the installation
The line on the datasheet saying 'maintenance: front' or 'maintenance: rear' concerns which direction a faulty module can be removed from. Our indoor GOB panels are front-serviceable, while the outdoor SMD series (P3, P4, P5) is rear-maintained. This decision becomes final at the moment of installation: rear service needs technician access behind the wall, which on a surface built into a wall plane or mounted on a facade often simply does not exist. This is the question asked least often before purchase, yet in the long run it determines how much time and cost a future repair will take. The advantage of modular construction shows up exactly here: given access, a faulty panel can be lifted out and replaced in minutes - provided the replacement comes from the same production batch, or its shade may differ from its neighbours.
Refresh rate, grayscale, viewing angle
Refresh rate states how many times a second the module redraws the image. To the naked eye no flicker is visible above 1,920 Hz, but in front of a camera the situation is different: recordings and live broadcasts need at least 3,840 Hz to avoid banding. Our indoor GOB module datasheets show 3,840-6,000 Hz and the outdoor SMD series 3,840-7,680 Hz, with ≥7,680 Hz on the outdoor P2.5. The grayscale is 14 bit (14-16 bit on the outdoor P2.5): this gives the fineness of the dark range, that is, whether the tones of a night scene merge into one another. A viewing angle marked H160° / V140° means that colour accuracy is maintained within 160 degrees horizontally and 140 degrees vertically - on a facade wall the horizontal figure matters more, and it varies by type: the outdoor P2.5 datasheet, for example, gives H 140° ± 10. Lifespan is 100,000 operating hours on every one of our module datasheets - an L50-type figure, meaning brightness falls to half the initial value after that time; at 12 hours a day, that is 22-23 years of operation. Brightness degradation over three years is at most 15 per cent according to the outdoor P2.5 datasheet.
Consumption: average and peak W/m², and why the difference matters
Two consumption figures appear on the datasheet, and we use them for different purposes. Average consumption applies with typical, mixed content, and it is the one for estimating the monthly electricity bill; peak consumption is measured on a full white image, and it is the one to size the power supply, the feed cable and the circuit breaker to. In orders of magnitude: average operating consumption of a LED wall is 150-300 W/m², rising to 600-800 W/m² at peak - that is our site-wide general statement, and our article on consumption uses the same. Against that, our own module product pages spread wider: the average moves between 126 and 278 W/m² and the peak between 380 and 836 W/m² depending on build - that spread is our catalogue's data, not a general rule. Anyone sizing to the average will find the wall dims or flickers on white content. Two specific comparisons from our product pages: the P2.5 indoor GOB module is the most economical in the range at 126 W/m² average, while the outdoor P3 consumes 278 W/m² - the difference is largely the price of brightness readable in sunlight. The 181 W/m² of the P1.86 module is about 22 per cent less than the P1.25's 231 W/m², which is a meaningful annual saving on walls with many operating hours. Sometimes only the peak figure appears on a datasheet - as with our outdoor P2.5 (≤648 W/m²); in that case the average has to be requested separately, because the electricity bill follows from it.
Markings on single-colour, seven-colour and full-colour modules
Not every module plays video, and the marking gives that away too. The designation full colour or 16.7 million colours means the complete RGB gamut - that is what you need for moving images, photographs and brand video. Single-colour modules (red, green, blue, yellow, white, pink) contain a single LED colour per pixel and are for scrolling text, price information and opening hours; these are the classic P10 outdoor panels, at 32 x 16 pixels resolution per module. There is an intermediate category too: the seven-colour module works with seven pre-programmed colours rather than continuous gradation - excellent for eye-catching lettering, unsuitable for video. If you only want to display text, the price and consumption of a full-colour module are unnecessary. The catalogue modules - the single-colour and seven-colour P10s, the P4 indoor, the P4 PRO and the P8 - carry a minimum order quantity of 5 pieces on their datasheets, which is about a quarter of a square metre of surface.
Module, panel or cabinet? The three words are not the same
In everyday speech 'LED display panel' can mean all three, but in the trade they differ. The module is the 320 x 160 mm base unit: a printed circuit board carrying the LEDs, the driver ICs and the HUB connector. The cabinet is a frame structure into which several modules, one or more power supplies and a receiving card are fitted; this is the transportable, assemblable unit - demountable, hireable and event walls are built from cabinet systems. The word panel in lay use denotes sometimes the module and sometimes the cabinet, so when requesting a quotation it is always worth clarifying which was meant: a 'panel price' can refer to a twentieth of the area you had in mind. So when you search for a product under 'LED module', the LED modules product page shows the 320 x 160 mm base units, not finished cabinets. On fixed installations, modules can also be built into a plasterboard profile structure or a laser-cut metal frame - these two construction methods are part of our range alongside the cabinet system.
What do the markings tell you about the module's price?
A module's price is made up of a few clearly identifiable factors, all of them readable from the datasheet. The first is the pixel count per square metre: sixty-four times as many LEDs and proportionately more driver ICs in a P1.25 module as in a P10. The second is the origin of the LED chip: a chip from an identifiable manufacturer with the same batch number costs more than one assembled from mixed sources, but it is what keeps the surface an even colour two years later. The third is the GOB potting, an extra manufacturing step. The fourth is the class of scan rate and refresh rate: a sparser (closer to static) drive and a refresh above 3,840 Hz need more driver ICs. The fifth is quantity. And finally: the price of the module is not the price of the wall - the support structure, the control system, the power supply, the installation and the training are separate items you should see on separate lines in an itemised quotation.
Choose in four questions
Once you know the markings, the choice simplifies to four questions, in this order. First: how close do the nearest viewers stand? That gives the P value - the pixel pitch in millimetres is roughly the physical minimum viewing distance in metres, and the comfortable band used for design is 2.5-3 times that (P4 → 10-12 m, P10 → 25-30 m). Second: is it in direct sunlight? If so, you need brightness above 4,200 cd/m² and outdoor ingress protection, which automatically means a sparser scan and a larger LED package. Third: can you get behind the wall? If not, you need a front-serviceable module, even if the rear-serviceable version would be more favourable. Fourth: will it be in front of a camera? If so, 3,840 Hz refresh is the entry point. Those four questions settle most of the module choice - the rest (power supply, support structure, cable routing) has to be looked at on site, which is why we add a free site survey before we manufacture anything.
Expert tip
On the datasheet, always look at the scan rate and the brightness together - those two figures together reveal whether the module really is an outdoor one. For outdoor use, brightness above 4,200-4,500 cd/m² is what you should expect alongside a scan between 1/8 and 1/16; if an 'outdoor' module datasheet shows a 1/32 or denser scan with brightness below 1,000 cd/m², it is an indoor panel in an outdoor housing, and it will be unreadable on the first sunny afternoon. The second pair to read together: the 'IP65 (front)' marking and the planned installation. A front-sealed module belongs in a cabinet or a closed frame - if you mount it outdoors, exposed and with no rear closure, the protection rating protects nothing.
Common mistakes
1. Looking only at the P value and leaving the other seven parameters (package, scan, IP, HUB, service side, refresh, consumption) to the supplier - yet these decide whether the module can be installed at the site at all. 2. Putting a module with indoor brightness (≥400-500 cd/m² on our GOB panel datasheets) into a sunlit window or onto a facade, where a figure above 4,200 cd/m² is needed; the content is simply invisible by day. 3. Reading the 'IP65 (front)' marking as full protection, and mounting the module outdoors with no frame or rear closure. 4. Sizing the power supply and the feed to average rather than peak consumption - on our module product page datasheets the average is 126-278 W/m² and the peak 380-836 W/m², more than a threefold difference; on a full white image the wall dims or flickers as a result. 5. Choosing a rear-serviceable module for a wall built into a wall plane or a facade, where there is no subsequent access behind the panel. 6. Confusing the two viewing-distance figures: the pixel pitch in millimetres is the physical minimum in metres, and the comfortable band usable for design is 2.5-3 times that (P4 → 10-12 m, P10 → 25-30 m) - conflating them produces a pitch that is either too fine or too coarse. 7. Buying a module without a matched controller and power supply; the controller has to know the HUB type, the scan mode and the chipset, or the panel will not start at all, or will light with the wrong colour order. 8. Ordering a full-colour module for a job that only needs text - a single-colour or seven-colour P10 panel does the same at a fraction of the pixel count and consumption.
| Module | Resolution per module | Pixels/m² | LED package | Scan | Brightness (cd/m²) | Comfortable viewing distance (pitch x 2.5-3) | Consumption average / peak (W/m²) |
|---|---|---|---|---|---|---|---|
| P1.25 indoor GOB | 256 x 128 px | 640,000 | SMD1010 | 1/64 | ≥500 | 3.1-3.8 m | 231 / 694 |
| P1.53 indoor GOB | 208 x 104 px | 422,500 | SMD1212 | 1/52 | ≥500 | 3.8-4.6 m | 224 / 673 |
| P1.86 indoor GOB | 172 x 86 px | 288,906 | SMD1515 | 1/43 | ≥500 | 4.7-5.6 m | 181 / 543 |
| P2 indoor GOB | 160 x 80 px | 250,000 | SMD1515 | 1/40 | ≥500 | 5-6 m | 173 / 521 |
| P2.5 indoor GOB | 128 x 64 px | 160,000 | SMD1515 / 2020 | 1/64 | ≥400 | 6.3-7.5 m | 126 / 380 |
| P2.5 outdoor SMD | 128 x 64 px | 160,000 | SMD 1R1G1B | 1/16 | ≥4200 | 6.3-7.5 m | not stated / ≤648 |
| P3 outdoor SMD | 104 x 52 px | 105,625 | SMD1415 | 1/13 | ≥4500 | 7.7-9.2 m | 278 / 836 |
| P4 outdoor SMD | 80 x 40 px | 62,500 | SMD1921 | 1/10 | ≥4500 | 10-12 m | 271 / 814 |
| P5 outdoor SMD | 64 x 32 px | 40,000 | SMD1921 | 1/8 | ≥4500 | 12.5-15 m | 271 / 814 |
A few questions and you get the recommended pixel pitch, the size and an indicative price.
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