OK so a quick request, please read the full post before replying as I've asked elsewhere and had people say things "Sounds like a dud cable" or something along those lines. I understand it is long, but I do appreciate your time investment and assistance.
So I have an ASUS R9 Fury Strix Direct CU III GPU - what a mouthful. I also have 3 monitors connected to it as follows from left to right:
- Samsung LU28D590D/XY 3840x2160@60Hz
- BenQ XL2730Z 2560x1440@144Hz
- Samsung LU28D590D/XY 3840x2160@60Hz
I'm using the Displayport cables that came with the monitors, from the box. All is working absolutely fine, not so much as a flicker or even a single pixel out of place.
However, and this is where the drama begins. I have a desk that I can raise/lower, one of those electric height adjustable desks. I recenlty built a new PC and my tower sits on the floor. When raised, the cables are not long enough to reach all the monitors. So off I went, and researched how long a Displayport cable can be, and the certification says the maximum limit is 3m without an active adapter.
OK fine, I went and purchased 3 new Displayport cables, fully certified. 1x2m in length for the monitor closest to the tower, and 2x 3m in length for the other two.
I tried the
Comsol brand first as they were cheap.
All 3 monitors showed "no signal detected" messages on the OSD.
I returned those and looked for a better brand, eventually
settling on Startech.
The Samsung monitors displayed a picture, but it was limited to 720p@30Hz. Hardly acceptable. The BenQ showed "no signal detected". After talking to Startech tech support, they noticed that the bundled cables that came with the Samsung monitors, were 20pin/20conductor cables. Startech's ones are 19/19 only.
So I returned those too... retailers the world over are loving me right now.
😕On to brand #3. I went
with Alogic. With these cables, the Samsung monitors showed a picture. However it flickered rapidly on/off and had strips of corrupted pixels all over the place. Essentially no go. The BenQ monitor worked fine with the 2m cable.
At this stage, I was frustrated and contacted Samsung's technical support. After some back and forth (they were super helpful actually) they said that they believe my GPU isn't outputting a high enough voltage to created a reliable signal over a 3m Displayport cable. They suggested getting an active Displayport adapter, or increasing the GPU voltage. Researching online and active Displayport adapters are only needed for cables beyond the specification max, ie from 3m to 30m. <= 3m is within the specification.
So I contacted ASUS, whose technical support is being a little less helpful than Samsung's, and they are saying I can't adjust the voltage output for the GPU Displayport ports, and that the cable is (to quote them) "awfully long". I don't have as much confidence in the ASUS tech support given the support ticket transcript so wanted to ask the community:
Has anyone else had this issue?
Are Samsung correct, the GPU voltage output is insufficient for anything longer than the included 1.2m Displayport cable?
What to do?
Is there any way to verify what I am being told? I'm going to borrow a multimeter from a friend and check the cable resistance, to see if it drops off significantly when compared to the bundled cables.
Surely I can't be the first person on the internet to encounter this and want a longer cable... or am I? o___o