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Can't go above 75hz? And other questions
01-16-2017, 10:56 PM
Post: #1
Can't go above 75hz? And other questions
Hello. CRU is amazing, but I have several concerns and questions about it. First of all, here are my relevant specs:
ASUS VS228H-P
AMD R9 280X

1- I can't seem to be able to go above 75hz, with a pixelclock of 174.57mhz. I've applied the pixelclock patcher successfully, and the HDMI block, but they don't seem to have done much. Is my monitor just really unable to go beyond that?

2- Since overclocking my monitor, I've seen a few black lines appearing across the screen, which worry me. It has only happened 2-3 times in the past 2 days, which isn't bothersome in itself, but I fear I may be damaging my monitor.

3- I'm using MSI afterburner to monitor framerate and frametime while gaming. My framerate is definitely going to 75fps, but my frametime remains exactly the same as when I'm at 60fps. Why is that? I've compared between 60 and 75 on my monitor, and 75 is visibly smoother.

4- Should I bother adding any of the audio blocks?
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01-17-2017, 03:14 AM
Post: #2
RE: Can't go above 75hz? And other questions
(01-16-2017 10:56 PM)Erin Wrote:  Hello. CRU is amazing, but I have several concerns and questions about it. First of all, here are my relevant specs:
ASUS VS228H-P
AMD R9 280X

1- I can't seem to be able to go above 75hz, with a pixelclock of 174.57mhz. I've applied the pixelclock patcher successfully, and the HDMI block, but they don't seem to have done much. Is my monitor just really unable to go beyond that?

2- Since overclocking my monitor, I've seen a few black lines appearing across the screen, which worry me. It has only happened 2-3 times in the past 2 days, which isn't bothersome in itself, but I fear I may be damaging my monitor.

3- I'm using MSI afterburner to monitor framerate and frametime while gaming. My framerate is definitely going to 75fps, but my frametime remains exactly the same as when I'm at 60fps. Why is that? I've compared between 60 and 75 on my monitor, and 75 is visibly smoother.

4- Should I bother adding any of the audio blocks?

1 - Have you tried tightening your timings? I have an LG E2441V-BN and these are the timings I'm using.
[Image: 8f1766ba67.png]

2 - Possibly your monitor not being able to handle the high pixel clock. Tightening your timings may fix that.

3 - I'm not sure on this. Have you tried testing for frameskipping?

4 - Only if you use audio on your monitor, which I don't think it supports.
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01-17-2017, 04:51 AM (Last edited: 01-17-2017, 05:28 AM by Erin)
Post: #3
RE: Can't go above 75hz? And other questions
I just tried putting in the same numbers as you and it made my screen all blurry and shaky. That was weird. No damage caused, though. Anyway, while I was there, I decided to try the "LCD reduced" preset and it lowered the pixel clock to 164mhz and hasn't caused any problem to the image so far. I'll keep it at that and see how it goes. What are the downsides of tightening the timings? I don't see any so far, but surely there must be a catch.

I just did that frameskipping test and it came valid. That's reassuring.

I don't have audio on my monitor. I'll just ignore that then.

Thank you for trying to help me.

EDIT: When using the LCD reduced preset, my GPU becomes unable to downclock itself past a certain point (it's stuck at 42c when normally its 32c when idling). Definitely not something I want.
EDIT 2: Ok, after reading the main thread again, I figured out that this problem was caused by gpu memory overclocking. That's interesting, because I never overclocked the card's memory. It was on 1600mhz by default, yet after googling, it turned out that 1500mhz is its real default clock. I guess Asus just ships them overclocked. But even after turning it down to 1500mhz, the gpu still can't clock itself properly. Why?
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01-18-2017, 03:58 PM
Post: #4
RE: Can't go above 75hz? And other questions
What happens when you go above 75 Hz? If the monitor says "out of range" or "not supported" or shows a black screen, then chances are the monitor's firmware probably doesn't accept refresh rates greater than 75 Hz. You shouldn't need the pixel clock patch with HDMI if you have the HDMI support data block.

Read the main thread notes again. You're mixing up two different problems. The R9 280X requires the "LCD standard" vertical blanking/total to reduce the memory clock when idle. You can still reduce the horizontal values if necessary.

(09-07-2012 09:06 PM)ToastyX Wrote:  
  • The video card will not reduce clock speeds when idle if the vertical blanking/total is too low. Horizontal values can still be reduced if necessary.
    • AMD/ATI cards require the "LCD standard" vertical blanking/total to reduce the memory clock when idle.

The other issue only applies if you see screen corruption with video acceleration when the memory is overclocked or when using multiple monitors. Using the "LCD standard" vertical blanking/total also works around that issue.

(09-07-2012 09:06 PM)ToastyX Wrote:  
  • AMD/ATI cards have a design limitation that causes video acceleration to scramble the screen if the vertical blanking/total is below standard with the video card's memory overclocked or with multiple monitors connected. Skype is known to trigger this problem. Either don't overclock the video card's memory, or use the "LCD standard" vertical blanking/total.
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