LCD MONITORS

dell-up3218k-image2We use portable computers and they really made the LCD possible for the PC. When our Dell P991 monitor finally failed we replaced it with a parade LCD panels.

Modern LCD displays are called active matrix. Each pixel is controlled by a transistor making it much brighter. Modern LCD panels now use LED for backlighting which should improved durability significantly.

ASPECT RATIO

LCD panels are available with 4:3, 5:4, 16:9 and 16:10 aspect ratios quite readily. Some vendors mount a pair of panels side by side for a very anamorphic screen. We used to use an old machine running Windows 3.1 on a 640×480 16-color screen. Many cheaper portables had monochrome screens. Desktop LCD panels came to market in the market with Windows 95 but they were very expensive. CRT monitors were already low cost but recently LDC panels have come down sharply in price enough to saturate the market. With the power savings alone, a new LED PCD panel pays for itself quickly.

RESOLUTION

LCD panels have been manufactured in a wide range of resolutions. HD 1920×1080 will be mainstream for several years to come. The DirectX SDK has the ability to enumerate all standard video modes so its possible for a game to present a large number of them. Most games in practice support only a few more standard modes within the available ones to simplify menus. The monitor also communicates with the driver to assemble the available video modes.

HDTV

ATSC has several resolutions for broadcast. Some channels broadcast at 1280x720p but today most now use 1920x1080i.

1440×900 GAMING

Earlier widescreen panels generally are not as anamorphic as HD with their 16:10 aspect ratio. The lower resolution is also less demanding for gaming. Our old panel was driven by a GTX 260 which provided excellent game play. Recent games have general support for 1440×900.

1920×1080 GAMING

Reviewing several internet retailers found low cost 21.5″ panels with full 1080p for $99 at several retailers as a feature in late 2012. These cheap panels typically use VGA and DVI only. LCD panels support the legacy resolutions rather well for older games.

Doom 3 BFG is a republishing of the original 2004 game and the engine is updated to support 1080p. The original Doom 3 only supported 1600×1200 max. Quake 4 with patches also supports 1080p. We have the DVD version of Painkiller and that version of the game is patched to support 1080p natively. The original Crysis works fine at 1080p.

Generally games from 2007 onwards when newer titles started ramping up will have 1080p as an option. Some older titles have patches that add additional resolutions and we offer them with ever game review if possible.

Quake 2 is open sourced so somebody fixed the game to add more resolutions including full 1080p. Quake 2 is playable at 1920×1080 but the level of detail is being stretched a bit.

2560×1440 GAMING

IPS panels are available with WQHD 2560×1440 pixels in a 27″ format early in 2011 but they have remained relatively expensive. Mainstream 22″ and 23″ panels will likely transition to this resolution through 2015.

Many games that support scaling up extreme resolutions lack the textures along with engine issues. Rage is more demanding of VRAM as it ships with larger textures which make the game world look much better at higher resolutions.

2560×1600 GAMING

About 2005 Apple released a professional 30″ panel with 2560×1600 resolution. HP and Dell also offer this class of panel. The more recent models of 30″ panels have faster response times making them more suitable for gaming. Generally games from 2007 also support 2560×1600. SLI/CFX is required to achieve any kind of playable performance.

3840×2160 GAMING

Early 2013 testing of 3840×2160 gaming showed that even 3-way GTX Titans X were not powerful enough to play the most demanding games available. In 2017, high-end 14nm video cards are capable of playing games at 3820×2160 but they are over $500.

Wolfenstein: The New Order is estimated to need at least 16 TFLOPS to run the game at 3840×2160 and maintaining 60fps.

3820×2160 televisions fell in cost rapidly and in 2017 models under $500 were being advertised.

7680×4320 GAMING

8K is a doubling of both vertical and horizontal resolutions of 4K UHD which is 16x the pixels of HDTV. The best film scanners are made by Baraka. They scan film at 8192×4608 which is the basis for 8K UHD. Moving this to the consumer will require a new generation of optical media as BDXL is limited to 128GB which is far too small for the typical feature film with any kind of bandwidth. Work to make lasers work in the UV range have been difficult.

Extreme panels are available but they typically are beyond $50,000 in 2013. Panels have to be make from a tiling of more modest 2K panels combined with a bank of video cards to drive it.

The Dell UltraSharp UP3218K was the first true 8K panel to become available in 2017 made from a single IPS LCD element.. The panel needs a pair of DP 1.4 connections to provide enough bandwidth.

MULTIPLE PANELS

Some extreme systems have 3 panels arrayed on a desk. This gives the system 5760×1080 resolution which is extremely demanding.

SPECIFICATIONS

There are only a few specifications for LCD panels used in the industry. In the last couple of years little has changed.

PEDESTAL

The video electronic standards association (VESA) has some standards for the pedestal and mounts. The idea to make it easy for vendors of monitor arms, pedestals and wall mounts to all work together.

The cheapest panels typically have extremely limited adjustments. Typically they can tilt forwards and backwards to match a viewer’s height better. Better pedestals have height adjustment which leads naturally to the idea of rotation into portrait mode. Our PA238QR has such a pedestal. In portrait mode, reading or writing one large page is more natural.

Wall mounted monitors are popular for retail displays. They can be used to show advertisements and other information of interest to consumers.

RESPONSE TIME

Better monitors usually have a faster response time. We noticed some 2ms panels but TN panels have inferior color to IPS panels. Our PA238QR is 6ms and its fine with games even when the action is dynamic. Realistically any panel with under 15ms response time will work fine for games.

CONTRASTmonitor-contrast

A spec much hyped by manufacturers (be suspicious of their claims), this is the difference in light intensity between the brightest white and the deepest black.

Higher LCD contrast ratio, whether ANSI or dynamic, can have the following benefits: better blacks, higher brightness, wider grey scale and color range, better shadow detail definition and increased perceived sharpness.

Today many claim ridiculous levels of contrast. The native contrast is the real value. Contrast is most important for digital photography and video. Professional Photoshop users take full advantage of high contrast displays.

Many games use dark contrasts. This borrows from the horror films or film noir which use many darker scenes.

LUMINANCE

Brightness; a measure of how much light a panel can produce. Luminance is expressed in candelas per square meter (cd/m2). A measurement of 200 to 250 cd/m2 is OK for most productivity tasks; 500 cd/m2 is better for TV and movies.  LED back lights are more durable compared to the older cold cathode florescent ones.

Remember the human eye adapts to changing brightness. Most panels are very bright and few are able to exceed 300 cd cd/m2.

BACKLIGHT

Older monitors use a cold cathode fluorescent (CCFL) back light. In recent years the LED models have completely replaced the older CCFL back light. LED backlights reduce power consumption by 50% giving vendors the opportunity to market the Energy Star rating. There is also the mercury used in CCFL.

LED back lights are usually placed along the bottom of the screen. Some vendors put another row on top. The brightest screens will use LED back lights are all four sides. The more backlight the brighter the screen will be.

Mainstream panels use blue LED bulbs with a phosphor. Obviously the color reproduction is far from ideal. There are better panels available that use discrete RGB but they are extremely expensive.

COLOR DEPTH

Almost all cheap LCDs (such as typical twisted nematic types) use dithered 18-bit color (64 × 64 × 64 = 262,144 combinations) to achieve faster transition times, but they must use either dithering or Frame Rate Control to fake 24-bit-per-pixel true color, or throw away 6 bits of color information entirely. The best LCD displays (typically IPS) can display 24-bit or greater color depth. More recently panels with even more colors such as 30-bit-per-pixel Deep Color which attempts to improve the result. Video cards are designed for 24-bit color which is the reason we selected the PA238QR which natively is also 24-bit color.

spectrum

Our Asus PA238QR features genuine 24-bit color which makes it much better looking compared to cheaper TN panels. The top model PA248Q features 36-bit color but its expensive. IPS panels are still relatively expensive but prices have come down. Video cards have both 24-bit and 32-bit integer instructions so moving the Deep Color is possible over time.

We have a HP D7160 photo printer that really emphasized the extent of the problem. The D7160 uses 6 cartridges for ink due to the color gamut limitations of RBG and CYM. Digital cameras use a CCD which is designed around the sRGB color gamut, the same as HDTV.

The smaller triangle shows the HDTV color space and the larger triangle shows the larger UHDTV color space.

COLOR SPACEUHTV Color space

Radeon graphics cards support more color options than GeForce. Both support the traditional RGB primary color system. Using HDMI, our HD 6970 offers YCbCr which is the default. The HD 6970 also supports 4:4:4 and 4:2:2 pixel formats.

CONNECTIVITY

Since the beginning of LCD panels, VGA was replaced by DVI which is a digital port as LCD is digital in nature. The television market introduced HDMI which combines a digital signal with audio. Now more recently is DisplayPort which is used by some high-end panels.

Cheaper panels usually ship with VGA and DVI connectors and better panels with all 4 ports are now widely available. PCI Express cards with both HDMI input and outputs are available for a media center style setup. HDMI is mainstream with general consumer entertainment centers.

HDMI

HDMI is now the mainstream interface for LCD panels. HDMI 1.4 is about 10Gbps which is enough for 3840×2160@24fps.

HDMI 2.0 raises this to 18Gbps which is enough to support 60fps.HDMI 2.0 support will take several years as televisions and monitors are slower moving in the market.

VESA DISPLAYPORT

The VESA DisplayPort 1.2 has enough bandwidth to support 3840×2160@60fps easily. DisplayPort 1.3 has enough bandwidth for 7680×4320 panels.

VESA has also updated their standard to provide USB 3.0 ports on panels. Our PA2338QR provides four USB 2.0 ports which are handy for the wireless keyboard and mouse radio. Wireless game pads are popular with PC gaming. Now with USB 3.1 VESA will need to update their specifications slightly.

TECHNOLOGY

The mainstream twisted nematic (TN) monitors are the long standing mainstream technology. There are also many other approaches as vendors work to provide a better quality image. Panels have seen a lot of influence from television and film in addition to PC use.

IPS

In plane switching is a competing technology that provides a better looking image. Historically expensive, models are now moving into the mainstream.

IPS tend to be somewhat less responsive compared to a TN panel. Much development has been done to improve the performance and modern IPS panels are absolutely fine for games.

Super IPS uses a higher voltage to force the liquid crystal to change more quickly. This effectively boosts the response time. Our PA2338QR employs this to achieve its 6ms response time.

3D

As video card performance improves there has been a slow move towards 3D capable monitors. Typically such monitors need a 120 Hz refresh rate to deal with the needs of 3D.

3D has been around for decades and while some improvement have been noticed, for the most part using multiple monitors remains more popular.

We have the 3D glasses that are obligatory for 3D video. The scarcity of content means 3D may end up being nothing but a marketing term.

PERFORMANCE

SCREEN ROW COL ASPECT PIX RATE MEGA P/S MB/S
Omnitech OM19WD 1,440 900 1.6000 1,296,000 75 97 292
Acer AL 1916 1,280 1,024 1.2500 1,310,720 75 98 295
HDTV 1,920 1,080 1.7778 2,073,600 60 124 373
Dell P991 2,048 1,536 1.3333 3,145,728 66 208 623
WQHD 2,560 1,440 1.7778 3,686,400 60 221 663
30″ LCD 2,560 1,600 1.6000 4,096,000 60 246 737
4K UHDTV 3,840 2,160 1.7778 8,294.400 60 497 1,493
8K UHDTV 7,680 4,320 1.7778 33,177,600 60 1,991 5,971

AMD and NVIDIA now support for 3840×2160 resolutions with their latest video cards. With 4x more pixels, 4x more TFLOPS is needed for a given title, assuming it even supports UHDTV resolutions. The Asus PA321Q is actually a tiled pair of 2K panels so it uses a pair of HDMI or a single DisplayPort cable. The Panasonic’s TC-L65WT600 is the first TV to support HDMI 2.0, but prices will fall quickly.

Moving up to 8K will require even more stupendous performance increases. 8K is thus 16x more demanding compared to 1920×1080.

ROADMAP

Video is moving towards 4K and 8K formats which far exceed the pixel density in use with contemporary gaming machines. Japan’s NKK is investing heavily in the technology.

The problem with higher resolutions is the need for more bandwidth to support it. HDTV is using 6 MHz channels over the air, and 4K and 8K need far more bandwidth. NKK used a sophisticated fiber setup to demonstrate 8K recently. The had to use 16 dense wavelength channels to achieve 25 Gbps over a distance of 250 km.

INTEL

Roadmap to 4K

4K MONITORS

The video industry has a long history of using high quality equipment. A company called Red (established 2007) currently has their flagship camera capable of 4480×2304 and they also offer an expensive video card equipped to render this video in real-time. The GeForce 700 series and higher and the Radeon HD 7000 series and higher can display video at 4K resolution however GPU performance remains grossly underpowered for games.

In 2013 the 4K panels still exceeded $5.000.00 which is far from the mainstream. In 2015, 4K panels were available for under $1000. A flagship grade LG model we saw on demonstration was priced at $20,000 in July 2013. The set was being supplied  from a computer using its hard disk to supply the video feed. The color quality was excellent and the resolution looked excellent given the screen was 84 inch diagonally.

We noticed a few benchmarks using up to 4-way GTX Titans driving a single 4K UHDTV and using Metro 2033 cranked up achieved only 61fps.

The new Asus PQ321Q will be 31.5 inches with support for 4K60 using DisplayPort. The expected launch price will be around $3799. The panel is actually made from 2K panels and they use the DP multichannel protocol which then is distributed to the component panels. This becomes in effect a 2 panel array not unlike other multi monitor setups.

BROADCAST

Broadcast currently is configured around a 6 MHz band for audio and video. HDTV uses MPEG2 to compress the video stream for transmission. MPEG2 is good for 1920×1080 interlaced.

The broadcast industry has seen many changes. Much more is yet to come.