DisplayPort 2 meter cable 144Hz

[boju]

Hi.

Since having the Acer XB270HU for a few months, I have been having DisplayPort cable dramas with the signal blanking in and out. Now before I begin should mention the 1 meter cable the monitor comes with works like a charm but is a little short but not a total inconvenience for me at my desk and willing to just accept and be mindful when i pull the PC out. Albeit curious to know why this is happening, and what might you guys think.

PC Specs: Australia
Win10 64bit
i7 2600k @ 4.5
Asus P8P67Delux Bios rev 1503
2x 8GB Ripjaws 1333
Gigabyte Windforce GTX780 Driver Win10 355.60
Corsair HX750w

Before knowing about Vesa certification and different Bitrates the dramas went like this;

First 2m cable I try by Cablelist http://www.msy.com.au/viconline/pc-accessories/3293-8ware-rc-dp2-2-meter-displayport-cable-m-m.html

Blank display with 1440p @ 144Hz. Works in 1080p/1440p @ 60Hz.

Second 2m cable was Goldwire

Blank display again with 1440p @ 144Hz. Works in 1080p/1440p @ 60Hz.

The store I bought Goldwire from no longer stocks their DisplayPort cables and can't find any details on them. They now sell only Alogic by the looks of it which I've yet to try but i'll hold off for now.
http://www.centrecom.com.au/alogic-2m-display-port-cable-male-to-male

From this point, I learn about Vesa and HBR2. Then a month or so later I try a cable from here, third and last as of yet.

http://www.cablechick.com.au/cables/2m-premium-displayport-cable-male-to-male.html

I talk to them first, they reckon a lot of cables aren't made properly to spec which Vesa say them selves as well since talking to them too hence the DP logo certification program. Vesa reckons maximum bandwidth rate for DisplayPort 1.2 HBR2 is 17.8Gbps. Cablechick reckons Up to 21.6 Gbps.

Didn't get an answer from Vesa on length but Cablechick reckons no more than 2m length for reliable results and saying on their site as well 1440p 144Hz as tested above the add to cart button, I got excited.

IT WORKED!, I get a picture 1440p @ 144Hz. I was feeling fuzzy haha UNTILL I was walking away and corner of my eye I seen the monitor blink blank.... Ahh FFS, it blanks in and out every 3mins or so, interval like. So stuck the 1m back, again, not a problem.

Sorry for dramatising lol. So what do you think, could it be 2m DP is too long for 144Hz?

Cheers.

 

[joex444]

"HDMI is designed to sustain full bandwidth up to 10 meters of cable length, while Displayport can carry full bandwidth for up to 3 meters only, which virtually marked it unusable for most home theater projector applications." --Wikipedia on DisplayPort (viz Comparison to HDMI).

Theoretically, 1m or 2m should be indistinguishable. Pragmatically, your 1m cable works so I can't believe this is an issue with the monitor or video output. Further, you've said the 1m isn't too short for normal use but only makes things awkward when you need to tinker.

 

[boju]

"HDMI is designed to sustain full bandwidth up to 10 meters of cable length, while Displayport can carry full bandwidth for up to 3 meters only, which virtually marked it unusable for most home theater projector applications." --Wikipedia on DisplayPort (viz Comparison to HDMI).

Theoretically, 1m or 2m should be indistinguishable. Pragmatically, your 1m cable works so I can't believe this is an issue with the monitor or video output. Further, you've said the 1m isn't too short for normal use but only makes things awkward when you need to tinker.

Thanks joex444.

Yea it's not really an issue, but would be nice to have that bit extra length. I would guess its not uncommon for people to have their cases under desk as well, so there'd be bound to be people with similar issues and just compromised like I have, but for those looking for answers as well, this is just another potential bit of feedback out there on the net.

The drama's I went through which I didn't expect at all just wouldn't mind knowing is all. Seems there's a difference between theoretical and real-world performance concerning DP cables and bandwidth drop-offs over a certain distance. Anyone with experiences of their own is welcome to share. I'm thinking 1.8m would be the absolute max for 144Hz.

 

[MarkW]

If you want to run a passive copper DisplayPort cable as long as 50 feet, the standard says you'll be limited to 1080p resolution—but the spec is conservative, and in practice that 50-foot cable can carry enough data to support resolutions as high as 2560 by 1600 (sufficient for a 30-inch display).

Buy certified DisplayPort cables, and you will not have these issues.

 

[boju]

If you want to run a passive copper DisplayPort cable as long as 50 feet, the standard says you'll be limited to 1080p resolution—but the spec is conservative, and in practice that 50-foot cable can carry enough data to support resolutions as high as 2560 by 1600 (sufficient for a 30-inch display).

Buy certified DisplayPort cables, and you will not have these issues.

Thanks MarkW, it seems the limitations are apparent and while 1080p and 1600p are more likely achievable at longer distances, 144Hz is more demanding than resolution I believe as far as what I've seen with all cables tried.

Buying certified I thought I was doing with the last cable I tried;
http://www.cablechick.com.au/cables/2m-premium-displayport-cable-male-to-male.html

VESA Certified to HBR2 standards, this cable is capable of all current DisplayPort features including 3D, HD, 4K@60Hz, Multi-Channel Audio and more. Fully tested in-house on a Samsung U28D590 4K monitor at 60Hz from a Windows 8 Desktop PC.

 

[MarkW]

Sad. I know the demand on correct manufacturing processes gets higher and higher with all of these increases in bandwidth, but it should not be hard to get a functioning DP cable even for the highest levels of data carried.

 

[boju]

This is Australia mate lol =D Might not be world spread after all haha.

 

[MarkW]

You said that... LOL

Is that what they mean when they say, "Welcome to the Outback!"??

 

[boju]

Yea our bloody cables are made out of sticks -_-

 

[boju]

Haha, we're not that far back, sometimes It feels we're pretty close though. I'm sure I can order a cable from over there but think just take my time looking around some more before committing to some of the known cable brands that are 100% Vesa tested - Accell Cables or Startech Vesa actually recommended but cant get them here locally.

I'll try the cable on another PC (Win7) with GTX770 just in case there maybe something wrong with the signal strength emitted from the 780 being hot plug and all, just gota move some stuff. Being the same architecture though might not do any good but i'll try and let yous know the outcome, I have doubts its the case but will try anyway.

 

[boju]

Just a follow up if anyone was slightly interested. I tried the 2m cable on 770 (different computer Win7) and it did the same thing. So now I know

 

[MarkW]

Well, then you know what not to buy now...

 

[boju]

hahaha my wallet will be happy for now 😀

 

[boju]

Another update; this time the outcome is much better but still lays a ? somewhere.

I had given up, but thanks to Cablechick Australia, they took the initiative to see how things went with the original cable they sent out and got the ball rolling.

I sent the cable back for testing, an employee there with the same XB270HU monitor with a GTX980 had the cable running without problems, a single blink though over several hr period, nothing like what i had - blinking often and text going fuzzy after a few blinks. I believe him to have done the testing properly going by the manner in which we interacted.

They sent out another cable anyhow, same length at 2m. This time the fresh cable worked like a charm. No blinks @ 144Hz.

All i can imagine, which i meant by the ?, is the DP function is different somehow between the 7 & 9 series GTX over a certain length @ high Hz. Either architecture or brand, guess i'll consider that as a possibility.

 

[MarkW]

That is very possible. We are pushing more and more data through these cables, and each step up requires tighter tolerances.

I am glad that they worked with you and got that resolved.

 

[boju]

Cheers MarkW.

Actually, the guy was still testing the cable, had it connected still to his PC and this afternoon he replied back, he had blinking fits as well, just took a little bit longer. So that bit of feedback now changes everything i had thought. Not GPU differences, it's what you guys have said all along at the beginning of this thread, the bloomen cable...