Cant get 100hz Predator XB271HU

tomidacu

Hello i have xb271hu and amd radeon hd 6670, and i am using display port 2560x1440 85hz, but i wanna increase to 100 hz and i get (my english is bad idk how to say this) black flickers, black spots, black things..

In 85hz its going good, 0 problems

I have the latest drivers of this monitor and of this graphic card...

 

So what is the problem?

 

Thanks!

 

 

Cory-Acer

Hi tomidacu,

 

I'm fairly confident that this is a limitation of the video card. I've had another thread where we learned that that GTX 770 series just doesn't have the pixel clock speed to push the XB271HU past 120hz, and it is a more recent card that the HD6670. I would suspect that 100hz is the theoretical limit that it says it can push, but it's just not able to do so, and that's why the panel is flickering at that speed.

 

Cory

Vandragorax

Hi tomidacu,

 

Your problem is 95% going to be a bad quality Display Port cable.

 

Please can you test using the cable which came in the box with the monitor?  This should be rated for 4k so it can handle the badwidth needed for 2560x1440@100hz.

 

If you need to use a different longer DP cable, make sure to buy one which has in the description "rated for 4K" or something similar.  This means it is good enough quality to handle the bandwidth needed to push down it for the resolution and refresh rate.

 

I hope this helps, please let me know how you get on.

Vandra

tomidacu

Nono, i am using the original display port cable, 

I think that the graphic card is the problem maybe doesnt work with 100 hz..

When i going to choose "X" Hertz i only can choose till 100hz, 144 hz doesnt appears, but anyway i cant put 100hz for flickers and bla bla

 

So rare haha

 

Vandragorax

You say you've updated the drivers already so I'm not sure what else it might be.  It could still be a bad cable though, you can try a different one if you get the chance and see if it still does it.

 

http://www.amd.com/en-us/products/graphics/desktop/6000/6670

tomidacu

Yep, i have the latest drivers of graphic card and monitor haha, idk what to do

Cory-Acer

Hi tomidacu,

 

I'm fairly confident that this is a limitation of the video card. I've had another thread where we learned that that GTX 770 series just doesn't have the pixel clock speed to push the XB271HU past 120hz, and it is a more recent card that the HD6670. I would suspect that 100hz is the theoretical limit that it says it can push, but it's just not able to do so, and that's why the panel is flickering at that speed.

 

Cory

tomidacu

Thank you Cory, 

Im watching in geforce.com, theres nothing about max HZ of each graphic card.. i cant find the max hz.

So.. i dont know what graphic card i should buy, because there is nothing talked about max hz

 

Im watching for Gtx 980 TI, that gonna be good, right?

Vandragorax

You shouldn't have any issues with a 980ti if it's pixel pushing power which is causing the problem.

 

A 980ti has much higher pixel rate at 96 GPixel/s vs a 770 at 33.5 GPixel/s.  More than 2.8x higher pixel rate.

 

Your Radeon HD 6670 only has a pixel rate of 6.4 GPixel/s... so I'm not surprised you're having issues with that card.

 

Source:

http://gpuboss.com/gpus/GeForce-GTX-980-Ti-vs-GeForce-GTX-770

https://www.google.com/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=radeon+hd+6670+pixel+rate

Cory-Acer

Here is a tool that may help (or cause confusion): http://www.monitortests.com/pixelclock.php

 

Ya, I own a XB271HU and have a 980ti going without issues. I think to get to 144hz, you'd probably want to look at aleast a 960. My understanding is that the 770 and even 780 are capped at 120hz.

 

Cory

IronFly

970 for sure works at 144Hz

tomidacu

Is there a posibility to get 100 hz with "http://www.monitortests.com/forum/Thread-AMD-ATI-Pixel-Clock-Patcher"?

 

but i was watching that is only DVI or HDMI, not dp haha

 

Thank you for all