• 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?

zAAm

zAAm

Joined
Mar 27, 2005
Messages
1,009 (0.14/day)
Location
South Africa
System Specs
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:
GerKNG

GerKNG

Joined
Feb 6, 2021
Messages
2,628 (2.25/day)
Location
Germany
System Specs
System Name Sunk Cost Fallacy
Processor AMD Ryzen 7 7800X3D
Motherboard ASRock B650E Steel Legend Wifi
Cooling Arctic Liquid Freezer II 360 Rev. 7
Memory 2x16GB G.Skill Trident Z5 NEO 6000 CL30
Video Card(s) Sapphire Nitro+ RX 7900 XTX Vapor-X
Storage WD Black SN850X 1TB + 2x 2TB, 2x 4TB Crucial MX500, 4TB Samsung 870 Evo.
Display(s) Alienware AW2723DF, LG 27GR93U, LG 27GN950-B
Case Lian Li O11 Air Mini
Audio Device(s) Bose Companion Series 2 III, Sennheiser GSP600 and HD599 SE - Creative Soundblaster X4
Power Supply bequiet! Dark Power Pro 12 1500w Titanium
Mouse Logitech GPRO X Superlight & G502 X
Keyboard Corsair K65 RGB Mini, Razer Black Widow V3 TKL
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.
 
Q

QuietBob

Joined
Sep 21, 2020
Messages
1,490 (1.14/day)
System Specs
Processor 5800X3D -30 CO
Motherboard MSI B550 Tomahawk
Cooling DeepCool Assassin III
Memory 32GB G.SKILL Ripjaws V @ 3800 CL14
Video Card(s) ASRock MBA 7900XTX
Storage 1TB WD SN850X + 1TB ADATA SX8200 Pro
Display(s) Dell S2721QS 4K60
Case Cooler Master CM690 II Advanced USB 3.0
Audio Device(s) Audiotrak Prodigy Cube Black (JRC MUSES 8820D) + CAL (recabled)
Power Supply Seasonic Prime TX-750
Mouse Logitech Cordless Desktop Wave
Keyboard Logitech Cordless Desktop Wave
Software Windows 10 Pro
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?
 
zAAm

zAAm

Joined
Mar 27, 2005
Messages
1,009 (0.14/day)
Location
South Africa
System Specs
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
QuietBob said:
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?
Click to expand...
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?
GerKNG said:
why do you buy a cable (basically from 2009) in the first place?
buy a normal 1.4 cable and use this.
Click to expand...
Difficult enough finding a DP1.2 cable at this length. Couldn't source anything else locally.
 
W

Ware

Joined
Oct 26, 2018
Messages
203 (0.10/day)
System Specs
Processor Intel i5-13600KF
Motherboard ASRock Z790 PG Lightning
Cooling NZXT Kraken 240
Memory Corsair Vengeance DDR5 6400
Video Card(s) XFX RX 7800 XT
Storage Samsung 990 Pro 2 TB + Samsung 860 EVO 1TB
Display(s) Dell S2721DGF 165Hz
Case Fractal Meshify C
Power Supply Seasonic Focus 750
Mouse Logitech G502 HERO
Keyboard Logitech G512
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.
 
zAAm

zAAm

Joined
Mar 27, 2005
Messages
1,009 (0.14/day)
Location
South Africa
System Specs
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
Ware said:
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.
Click to expand...

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.
 
You must log in or register to reply here.
Top