I have a computer I want to use as a media center running Windows 7 on an AMD Radeon HD 6870. I have a 55" 4K TV (and 4K works, a small Android TV box runs in 4K on it).

The problem is that it's a cheap brand TV and apparently the engineers who built it forgot to change the reported max resolution to 4K... The model reported is ELUFT551, which is a 2014 55" 1080p TV. So obviously, my computer doesn't let me choose 4K as a resolution (max 1080p).

What I'm looking for is a way to either spoof the reported max resolution or force a custom resolution.

Is there a way to do this?

  • Can you please add the way your connecting, i am upgrading from 2 minidv to dvi, and one dvi to dvi. I thought i would just replace out one of the mini-dv to dvi runs, and use the dells dp to minidv in place of that. (not working) – Brian Thomas Jan 10 '17 at 5:44
  • my bad, turns out i had the dp cable plugged in the wrong dp port. – Brian Thomas Jan 10 '17 at 6:06
up vote 4 down vote accepted

I finally found a way to achieve this. Here's how to do it :

First, you need to patch the HDMI Pixel Clock on the card with this utility : http://www.monitortests.com/forum/Thread-AMD-ATI-Pixel-Clock-Patcher

Then, once it's done and the computer has been rebooted, you use Custom Resolution Utility (http://www.monitortests.com/forum/Thread-Custom-Resolution-Utility-CRU) to add the desired resolution to the available resolutions list.

I'm not sure if a reboot is necessary here, but then I was able to see the 3840x2160 resolution in the Windows display settings!

  • This utility claims to require "Windows Vista or later", yet this thread is specifically about Windows 7. Clarification? – Jackalope Oct 1 '17 at 15:24
  • @Jackalope I was using Windows 7 at the time, so while it might support Vista, 8 and 10, I didn't have the chance to test it. – Samuel Bolduc Oct 2 '17 at 14:59
  • That's not my question. The utility indicates that it does not support Windows 7, yet you indicate that it does. – Jackalope Oct 2 '17 at 22:30
  • Oh, I'm sorry. Windows 7 came after Windows Vista, so by saying "Windows Vista or later" I assumed it worked on Windows 7, which I was using at the time. – Samuel Bolduc Oct 3 '17 at 20:59
  • Ack, you're right. I had thought Vista came out after Win7. Apologies. – Jackalope Oct 5 '17 at 4:33

I cannot leave comments yet but the previous answer by Samuel Bolduc worked for me twice. Once about four months ago and again today. Every time an update comes form AMD I lose my 4K resolution. The following link provided by Samuel worked. http://www.monitortests.com/forum/Thread-AMD-ATI-Pixel-Clock-Patcher

That being said, my Norton 360 flagged it as harmful and removed it the second time. Not sure why the difference. Luckily I had the old file in my Recycle Bin and it worked. Same exact file as far as I can tell but Norton removed it the second time and not the restored file from my recycle bin.

I had to reboot but after that it worked and the 3840 x 2160 resolution option was back in Windows Settings.

I am using an AMD HD 6900 video card. Ironically the AMD Catylist Control Center still does not provide the higher resolution options but the Windows display settings do so that worked.

The accepted answer is correct. My desktop computer's graphics are driven by an AMD Radeon HD 5850 graphics card (no integrated graphics (CPU is an i7 860)). When I recently bought a 4k monitor, I thought I would only be able to run at 1080p resolution but following the instruction in that answer (on Windows 10), I am now able to use the 4k monitor at its native 3840 by 2160 resolution without any issues (I am not gaming on it obviously; 4k video playback is fine). This is contrary to max resolution specified on AMD's official specifications for the card.

  • The issue is with his TV, not the card – Blaine Aug 22 '16 at 3:49
  • 2
    @Blaine There was an issue with my TV, but AMD's website listed 2560x1600 as the max resolution the card supports too. By forcing the 4K entry in the choices Windows gave me, it fixed both problems, so this solution also applies to cases when the cards supports the resolution and the computer won't let it be set to 4K – Samuel Bolduc Aug 22 '16 at 14:06

2560x1600 is what I see as the max resolution for your graphics card.

That's on displayport/dvi. 1920x1080 on HDMI


4k resolution is 3840x2160

  • I have seen many people running 4K monitors on that card, but you're right that the AMD website officially says otherwise – Samuel Bolduc Mar 27 '15 at 15:49

I have a HD 6870 and use it with a 4K TV. I connect to the HDMI port using the HD 6870 Display port and from that display port I have a goFanco miniDisplayPort to HDMI 1.4 connector. Once you attached the HDMI cable to the TV everything should work fine.

The HD 6870 will run 4K (3840 x 2160 ) resolution at 30 Hz which is good for desktop work. If you want to play games set the resolution to 1080P and the monitor should upscale the image.

Remember that the video card was made before the concept of 4K was invented. So don't expect to play games on it or run 4 HD movies at the same time. Mine has a video reset every now and then and I don't know if it is the TV (I have the cheapest), the goFanco or the video card.

  • OP was talking specifically about the issue with his particular TV. – Blaine Aug 22 '16 at 3:49

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