4K@60Hz possible on HDMI 2.0 but not on DisplayPort 1.4?

[Inyerbones]

My monitor is the Acer VG 271UP, a 27", 1440p, 144hz IPS display.

Link to the monitor : https://www.acer.com/ac/en/MY/content/model/UM.HV1SM.P02 

 

I've been playing with the HDMI 2.0 cable that came with the monitor, and I've been able to play games like World of Tanks, GTA 5 and Warframe at 4k60fps and of course 1440p at 144hz as well, but I always thought that I was limited to 4k@60 because of the bandwidth limit of HDMI 2.0. 

So recently i've purchased a DisplayPort 1.4 cable (with the understanding that DP 1.4 supports 4k@120fps?) from Ugreen, https://shopee.com.my/UGREEN-DisplayPort-1.4-Cable-8K-4K-HDR-165Hz-60Hz-Display-Port-Adapter-Cable-i.64923440.2422829746

 

I plugged in the new cable and I tried going into the mentioned games, interested to see if i could increase the fps limit at 4k resolution but for some reason the option to even play at 4k isn't there anymore? All 3 of the games don't let me go past 2560x1440 and 144fps. 

 

I know my monitor isn't native 4k, but I kinda enjoy playing certain games at a high resolution but downscaled(not sure if i'm using the right word here) for the graphics even if I take a hit on the fps side of things. 

 

Am I missing something here? Is there something I'm supposed to turn on to enable playing games at 4k with displayport 1.4?

It's my first experience with a cable that isn't HDMI, really not sure if there's anything I'm missing here

[Eigenvektor]

What GPU are you using? To be able to use DisplayPort 1.4, both your GPU and your monitor need to support that standard. The cable needs to be good enough quality, but technically there's no such thing as a "DP 1.4 cable" (even if it is marketed as such).

 

I've found some conflicting information, but it's possible the monitor actually only has DisplayPort 1.2. Unfortunately Acer's own site doesn't mention the version that is supported.

[Inyerbones]

@EigenvektorI'm using a Gigabyte Aorus RTX 2070 Super. It has 3 DP 1.4s , 3 HDMI 2.0bs well as a Type C port for output. I don't think the problem is in my GPU. 

 

Yea i've been kinda confused about the actual version of the DP Port on my monitor as well. But let's say it is DP 1.2, doesn't DP 1.2 have the support the same resolutions and refresh rates as HDMI 2.0? 

 

By the way, are you saying DP 1.2 cables actually function the same as DP 1.4 cables and that it actually depends on whether the monitor and GPU have ports that support the DP 1.4 standard?

[Eigenvektor]

13 minutes ago, Inyerbones said:

@EigenvektorI'm using a Gigabyte Aorus RTX 2070 Super. It has 3 DP 1.4s , 3 HDMI 2.0bs well as a Type C port for output. I don't think the problem is in my GPU. 

 

Yea i've been kinda confused about the actual version of the DP Port on my monitor as well. But let's say it is DP 1.2, doesn't DP 1.2 have the support the same resolutions and refresh rates as HDMI 2.0? 

 

By the way, are you saying DP 1.2 cables actually function the same as DP 1.4 cables and that it actually depends on whether the monitor and GPU have ports that support the DP 1.4 standard?

Right, GPU shouldn't be the issue.

 

DP1.2 is limited to 4K @ 60Hz as far as I can tell. DP1.4 can do 4K @ 120 Hz (not 144Hz) without compression (Display Stream Compression, DSC). It can do more, but that requires additional support for DSC, both from the monitor and the GPU.

 

In regards to cables, here's a very good explanation:

 

[Inyerbones]

@Eigenvektor I see, thanks a lot for the link. 

 

Still pretty weird that suddenly with this new DP cable the option to even play at 4k at all has completely disappeared though  If my monitor isn't actually DP 1.4 compatible but is instead DP 1.2, shouldn't it give me the same choice of resolutions and frame rates as when I was using my previous HDMI 2.0 cable (4k@60hz max) ?