• Welcome to TechPowerUp Forums, Guest! Please check out our forum guidelines for info related to our community.

DisplayPort 1.2 cable - Cannot run 1440p @ 100Hz but can do 4K @ 60Hz?

Joined
Mar 27, 2005
Messages
1,009 (0.17/day)
Location
South Africa
Processor Intel i7-8700k @ stock
Motherboard MSI Z370 Gaming Pro Carbon
Cooling Corsair H115i Pro iirc
Memory 16GB Corsair DDR4-3466
Video Card(s) Gigabyte GTX 1070 FE
Storage Samsung 960 Evo 500G NVMe
Display(s) 34" ASUS ROG PG348Q + 28" ASUS TUF Gaming VG289
Case NZXT
Power Supply Corsair 850W
Mouse Logitech G502
Keyboard CoolerMaster Storm XT Stealth
VR HMD Oculus Quest 2
Hi guys,

I recently bought a longer cable for my PC in order to reach down to where it's sitting. I'm currently running an ASUS ROG PG348 3440x1440p ultrawide, at 100Hz without issue.
The cable wasn't specifically rated for this resolution, but it was rated for 4K @ 60Hz, and was DP1.2 rated, so busting out the calculator, I figured it would work:

4K @ 60Hz requires 12.54Gbit/s, and 3440x1440p @ 100Hz requires 12.75Gbit/s.

Testing it after I received it however, I found that it can do 4K @ 60Hz without issue, but fails to switch to 1440p @ 100Hz? Are they cutting it this close? DP 1.2 supports 17.28Gbit/s after all?

In fact, I can't get it to run at 3440x1440p @ 75Hz etc. either, and that definitely uses less bandwidth. Any suggestions?

Thanks.
 
Last edited:
Joined
Feb 6, 2021
Messages
798 (3.01/day)
Location
Germany
Processor AMD Ryzen 9 5950X (and a LOT of other CPUs)
Motherboard MSI B550 Tomahawk
Cooling Corsair H150i RGB Pro XT
Memory G.Skill Trident Z Neo 3600 Mhz CL16 (2x16GB)
Video Card(s) All Ampere, two 6900XTs and other RDNA2, all Turing, all Pascal, Vegas, 980 Tis and older.
Storage Corsair MP 600 Pro 1TB, 2x Samsung 870 QVO 4TB, Samsung 870 Evo 500GB (Backup)
Display(s) ASUS ROG STRIX XG27UQR / Samsung Odyssey G7 32"
Case Fractal Design Meshify S2 White TG / Noctua NF-A14 iPPC-3000RPM Fans
Audio Device(s) Bose Companion Series 2 III, Sennheiser GSP600 running through a SoundblasterX G6
Power Supply bequiet! Dark Power Pro 12 1200w Titanium
Mouse Glorious PC Gaming Race Model O, G903 Hero, G502 Hero SE, Deathadder V2, EC2-A
Keyboard ASUS ROG Strix Scope TKL DLX, Corsair K95, Logitech G815
VR HMD Oculus Rift S
why do you buy a cable (basically from 2009) in the first place?
buy a normal 1.4 cable and use this.
 
Joined
Sep 21, 2020
Messages
421 (1.05/day)
Processor AMD FX 8300 @ 4.5
Motherboard Asus Sabertooth 990FX R2.0
Cooling Thermalright Macho Rev.B
Memory 16GB Corsair Dominator Platinum 2400MHz CL10
Video Card(s) Asus HD7970 @ 1135/1750 + Prolimatech MK-26 + 2x 140mm
Storage 256GB Toshiba Q Pro MLC + 500GB WD VelociRaptor
Display(s) Dell U2412M
Case Cooler Master CM690 II Advanced USB 3.0 + Lamptron FC6
Audio Device(s) Audiotrak Prodigy Cube Black (JRC MUSES 8820D) + CAL (recabled)
Power Supply 750W Enermax Platimax
Mouse Logitech Cordless Desktop Wave
Keyboard Logitech Cordless Desktop Wave
Software Windows 7 Ultimate
How long is the cable? Unless certified by VESA, quality may be an issue. Perhaps the problem is a high refresh rate. Does it properly support anything over 60 Hz at lower resolutions?
 
Joined
Mar 27, 2005
Messages
1,009 (0.17/day)
Location
South Africa
Processor Intel i7-8700k @ stock
Motherboard MSI Z370 Gaming Pro Carbon
Cooling Corsair H115i Pro iirc
Memory 16GB Corsair DDR4-3466
Video Card(s) Gigabyte GTX 1070 FE
Storage Samsung 960 Evo 500G NVMe
Display(s) 34" ASUS ROG PG348Q + 28" ASUS TUF Gaming VG289
Case NZXT
Power Supply Corsair 850W
Mouse Logitech G502
Keyboard CoolerMaster Storm XT Stealth
VR HMD Oculus Quest 2
How long is the cable? Unless certified by VESA, quality may be an issue. Perhaps the problem is a high refresh rate. Does it properly support anything over 60 Hz at lower resolutions?
3m. I'll check today if I can run another standard resolution at higher refresh rate. My question is just, if quality was that much of an issue, how does it still support 4K@60?
why do you buy a cable (basically from 2009) in the first place?
buy a normal 1.4 cable and use this.
Difficult enough finding a DP1.2 cable at this length. Couldn't source anything else locally.
 
Joined
Oct 26, 2018
Messages
66 (0.06/day)
Processor Intel i9-10850K
Motherboard ASUS Z490-H ROG STRIX
Cooling Enermax ETS-T50
Memory Corsair Vengance LPX 3600
Video Card(s) PNY RTX 3070
Storage WD Black SN750 500GB + Samsung 860 EVO 1TB
Display(s) Dell S2721DGF
Case Fractal Meshify C
Power Supply Seasonic Focus 750
Mouse Logitech G402
Keyboard Logitech G510
Long shot here....
Are you using the 1070FE in your specs? Did you update it's displayport firmware?
Nvidia made a tool too check it and update if needed.
Also maybe check GPU-Z monitor info for DP link rate and lanes info and make sure it adds up.
 
Joined
Mar 27, 2005
Messages
1,009 (0.17/day)
Location
South Africa
Processor Intel i7-8700k @ stock
Motherboard MSI Z370 Gaming Pro Carbon
Cooling Corsair H115i Pro iirc
Memory 16GB Corsair DDR4-3466
Video Card(s) Gigabyte GTX 1070 FE
Storage Samsung 960 Evo 500G NVMe
Display(s) 34" ASUS ROG PG348Q + 28" ASUS TUF Gaming VG289
Case NZXT
Power Supply Corsair 850W
Mouse Logitech G502
Keyboard CoolerMaster Storm XT Stealth
VR HMD Oculus Quest 2
Long shot here....
Are you using the 1070FE in your specs? Did you update it's displayport firmware?
Nvidia made a tool too check it and update if needed.
Also maybe check GPU-Z monitor info for DP link rate and lanes info and make sure it adds up.

Yes, ironically every other component is different, but still have the 1070. Worth a shot to check the update. Also didn't know you can check the DP lanes with GPU-Z. Will take a look.
I mean, it works with the shorter 1.8m cable, so I'm not immediately expecting any driver or firmware related issue, but will check regardless.
 
Top