Using a UHD 4K TV as a Monitor -

Web-Feet Hits the Big Screen

With the advent of 4K monitors and TVs, the world now has access to ultra high definition content. For others however, 4K has opened a door to greatly improved productivity. This is especially true for those who rely upon extended screen real estate such as developers. The 4K form factor allows for the equivalent of four full HD (1080P) monitors, that puts most conventional dual screen set-ups to shame. Unfortunately, many PC and monitor manufacturers are yet to adopt this newly found productivity and instead are continuing to produce screens of a more conservative nature, therefore targeting smaller “retina” displays with higher pixel densities. The problem therefore lies with the fact that you cannot comfortably use a 27 inch monitor at ultra HD resolution without scaling.

Due to the issues discussed above and a little research elsewhere, in which there is a surprisingly little, we decided to opt for 4K TVs. The benefit of course is that TVs often come in much more vast sizes than their computer monitor counterparts. In our case we went for three 43 inch LG TVs with in-plane switching (IPS) panels. The downside of using TVs as monitors, particularly 4K TVs, is that both the TV and graphics card must support HDMI 2.0 in order to return a refresh rate of 60 hertz. Anything lower such as 30 hertz isn’t a huge problem, but you do notice certain actions, like dragging windows, feel more sluggish than usual. Having the TV running at 30hz is by no means a deal breaker but we would recommend trying it first if possible to make sure you are comfortable using this refresh rate before making a big investment in hardware.

In our case we have been using Nvidia GeForce GTX 960s to power our displays, but any graphics card above this would work equally as well and at the same time any AMD based card with HDMI 2.0 support would work too. In many cases the average office PC will require a graphics card upgrade in order to support 4K, likely combined with the need for a power supply upgrade. By default office computers tend to have very small power supplies that are designed to only power the bare essentials. All of this will of course need to be taken into account when working out the overall cost of a 4K system overhaul. We have been running 4k TVs as PC monitors on all three major operating systems including Windows, Mac OS X and Ubuntu (Linux).

The end result has meant that we are now able to emulate four full HD monitors on one display without the need for a multi monitor set-up, thus making our workflow much more efficient. Not only has switching over to 4K TVs bolstered our productivity it has also increased our desk space as it is no longer taken up by having two or three separate displays. It’s also an added benefit to have the extra vertical space, rather than otherwise having predominantly horizontal space.

As technology constantly improves, the cost effectiveness of upgrading to 4K has increased tremendously with many more lower end graphics cards now supporting 4K over the HDMI 2.0 interface. Nvidia have since released the GTX 950, which currently retails for around £120, supporting 4K at 60Hz through HDMI 2.0. All in all using a 4K TV as a monitor has proved to be a great success for us and has also been a great hit with many of our clients, who have more often than not commented on them when they see them in our office.

Setting up a 4K Monitor on a Mac (@30Hz)

See this Apple support page to find out if 4K is supported natively on your machine, https://support.apple.com/en-gb/HT202856.

On our Early 2013 MacBook Pro we tried a set up that worked for a while before breaking completely (see https://apple.stackexchange.com/questions/129653/early-2013-macbook-pro-with-4k)

Ultimately the flakiness of forcing the Mac to support a resolution it wasn’t intended to  was not suitable for normal work so we bought a new Mac Mini which supports 4k @ 30Hz out of the box (incidentally it would support 4k at 60hz via it’s displayport).

Setting up a 4K Monitor on a Ubuntu (Linux) Machine (@30Hz)

Installing the Nvidia drivers wasn’t the most straightforward on Ubuntu as the Display Manager service (lightdm) had to be stopped to install the drivers. This meant the running install had to done through a virtual console (Ctrl+Alt+F1).

This threw up another issue as the virtual consoles weren’t working after plugging in the Nvidia Graphics card. We found out this was being caused by the Kernel Mode Setting. The fix was just passing an extra parameter “nomodeset” when starting the kernel, which could be easily done via grub.

Once installed there was a nice GUI to customize settings. It can be run at 60Hz however there were few issues with the picture quality which were resolved by switching to 30Hz.

Full Instructions:

Force low level graphics for virtual consoles:

sudo gedit /etc/default/grub

#change line GRUB_CMDLINE_LINUX_DEFAULT… to GRUB_CMDLINE_LINUX_DEFAULT=”nomodeset”

sudo update-grub

sudo reboot

Download nvidia drivers: http://www.nvidia.co.uk/Download

Install nvidia drivers:

#start a virtual console (Ctrl+Alt+F1)

sudo service lightdm stop

cd Downloads  #directory where the drivers were downloded to

sudo ./{the downloadedfilename.run} #usually answer yes to all options

sudo service lightdm start

Finally set the resolution to 3840×2160 in System settings -> Displays

Setting up a 4K Monitor on a Windows 10 PC (@60Hz)

Setting up on Windows is reasonably simple, however it can require a couple of tweaks within the Nvidia control panel to obtain the best quality picture. Out of the box, picture quality looked considerably better running at 30Hz than it did running at 60.

However, changing the output colour format to RGB and updating the output dynamic range field to full in the Nvidia control panel made text look considerably better when running 4K at 60Hz.

Likely hardware costs (all costs are approx at time of article)

LG 43UF770V 43-inch Ultra HD 4K TV £600

GeForce GTX 960 £165

Corsair CX Series CX500 ATX 500W Power Supply £50

High quality HDMI cable £10

DisplayPort vs HDMI 2.0

We’ve not mentioned DisplayPort so far in this article and that’s because it’s a PC to PC monitor technology and isn’t supported by mainstream TV’s. In part this has been the main challenge as many 4k TV’s have good support for HDMI 2.0 and PC’s (GPU’s) don’t. As such this article focusses on using HDMI 2.0 as that’s what TV’s use and we wanted to make use of the larger format TV’s available versus PC monitors that generally use DisplayPort (for high bandwidth monitor connectivity). Incidentally, 4k requires the following bandwidths;

• 4K@60Hz requires 11.94Gbps
• 4K@30Hz requires 5.97Gbps
• HDMI 2.0 support a maximum throughput of 18Gbps
• HDMI 1.4 10Gbps
• DisplayPort 1.2 17.28Gbps
• DisplayPort 1.3 32.4Gbps

As you can see, 4K at 60hz exceeds the HDMI 1.4 spec but works at 30hz. 4k at 60hz requires either HDMI 2.0 or DisplayPort 1.2 or 1.3. So for our particular requirements HDMI 2.0 was the way forward.

Additional Notes:

http://www.geeks3d.com/20141202/tested-geforce-gtx-970-and-4k-60hz-on-hdmi-2-0/ – Info on HDMI and DisplayPort bandwidths.

http://tiamat.tsotech.com/4k-is-for-programmers – This article was the original source of our inspiration for trying out the 4k TV’s on our PC’s, along with a passion for technology.