The 4K in the Road
The Bumpy Trip into 4K DisplayLand
It was a beautiful November day in when I set out to replace my lovely 30-inch Apple Cinema display with a 40+ inch 4K display. “This will be great; what could be so hard?”, I asked.
Here I am six weeks later. I still have my 30-inch Apple Cinema display in place, and I am a better, happier, and wiser man for having taken the trip into 4K Migration Land. So what happened? Here’s the story.
I had four screens in play. There were three low/near screens; the (2560x1600) Cinema in the center, flanked by a pair of portrait-mode 4:3 (1200x1600) screens. Above those there was a single high/far screen. It was a 40-inch HDTV with alternate usage as my desktop and as a camera monitor for the performers in the new East Room.
The 40-inch HDTV does not have a composite input that is compatible with the analog cameras that I use, so an $8 RF modulator allowed me to use the antenna input. It was always disappointing picture quality, but I am unwilling to invest in a better modulator. The portrait screens are Dell 2007 FP’s and they have composite inputs in addition to DVI/HDMI inputs. Since DVI and HDMI are electrically equivalent, I am allowed to write the specs in this way.
A recording session in which I had to watch both the drummer behind me, and the trumpeter in the East Room led me to the conclusion that I needed to repurpose the use of the flanking Dell screens by engaging their composite inputs. That constraint led me to the executive decision to completely eliminate the 4th screen, and work with the three low/near displays.
All was well with my decision until I thought about getting back the missing 2-million pixels that the HDTV had in the high/far position. In round numbers, the Dell screens have 2-million pixels apiece, and the Cinema has 4-million pixels. Therefore the 10-million pixels I had with the four screens would drop to 8-million with three screens. All I would need is a 4KTV (3840x2160). The 8-million pixels in that 4KTV would combine with the 4-million pixels of the two Dell screens, and I’d increase my screen real estate to 12-million while consolidating to three displays. What could go wrong?
I ordered a $204 refurbished HIS IceQ 7950 video card that had been re-flashed with the Mac EFI-compatible firmware. It worked for 4 hours and then died. I sent it back.
I bought a $310 Seiki SE40UM 40-inch 4K screen. It came in a perfect nested pair of boxes, but the screen was damaged. I sent it back.
I researched other 4K screens because I didn’t want to take the relationship risk with NewEgg that could happen if yet another screen came in damaged. Along the way, I learned that in the world of 4K, the luminance resolution isn’t always the same as the color resolution. Where 1920x1080 is both the pixel count, the luminance resolution and the color resolution in a normal full-HD image, there are 4K screens where the luminance resolution is 3840x2160 while the luminance resolution is less than that at 2560x2160, or 2560x1080.
The nomenclature of how color resolution is denoted is somewhat bizarre, and requires a couple of long articles to explain. There’s an interplay between color resolution, refresh rate, data rate, the image processor within the TV, and the physical panel displaying the image. The full, perfect implementations are 4:4:4, and can readily display single-pixel lines of text in purple-on-pink. Other implementations that yield 4:2:2 or 4:2:0 can cause ‘greeked’ text that is illegible. It varies by refresh rate, and by the specific pixel grid in the LED panel. While some RGB sub-pixel panels are 4:4:4, and can do the full 3840x2160@60Hz for both luminance and color, there are other panels that have 4:4:4 electronics, but have RGBW (additional white sub-pixel) pixels that physically limit the color resolution to 2560x2160. These problems arise when a TV is used as a computer display, and are rarely, if ever visible with conventional TV or gaming usage.
On top of these TV-screen-as-computer-monitor problems, there is an ugly underbelly of HDMI standards and DisplayPort standards that push us out of our comfortable world of computer-optimized screens. While the regular HDMI 1.4 standard supports most 4K screens, as soon as you want to push 3840x2160@60Hz, you need to 18 Gigabits per second down that HDMI cable. That means HDMI 2.0. HDMI 2.0 doesn’t work with most video cards; there are three Nvidia card models (980, 970, 960) that can do that. Everyone else has to do a conversion from DisplayPort 1.2 to HDMI 2.0. Guess what? There is currently (December 2015) only *one* vendor in the world that can sell you a DisplayPort 1.2 to HDMI 2.0 adapter. Moreover, it isn’t available in the Mini-DisplayPort form factor that is common to my required AMD 7950. I spent the $50 to buy one, and another $7 to get a Mini DisplayPort to full-size DisplayPort adapter cable.
In parallel, I did my homework, and found that the 40-inch class screens that could do a 3840x2160@60Hz as 4:4:4 consistently cost about $800. As Daffy Duck (quoting Chester A. Riley) said,”What a revolting development this is!” That is far more than I was willing to spend on a mere convenience.
In a review of my primary application-driven requirements, things became more focused. I need to smoothly preview video in Final Cut Pro X. I need to see all of my busses, tracks, and plug-ins in SONAR and Logic Pro X. With my three ‘old’ screens totaling a mere 8-million pixels, and a working AMD Sapphire 7950 video card, I can make all of this happen.
Fortunately, a different HIS AMD 7950 video card popped up on Craigslist. The version of the card being sold allows two different firmware images to be chosen via a physical switch on the card. The seller also happened to be a super computer geek and nice guy. We worked out an additional deal for him to re-flash the firmware of the video card to have the Mac EFI firmware. That turned out to be a long side trip to run a script that required me to install the Java Developer Kit in Mavericks. Yosemite is newly locked down by Apple, and requires many hours of work to allow the JDK to work normally. I got through that, and sent the revised firmware to my new Craigslist friend who used his experience and tools to made it all work.
So this story has a net $150 spend for the new Mac-compatible HIS AMD 7950 video card, and a lot more understanding of what is underneath those fancy 4K screens at the local electronics emporium. Oh yeah, about the $50 DisplayPort 1.2-to-HDMI 2.0 adapter…I sent it back.
- Ted of TedLand
Dec 19, 2015