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ebkevinlee · 01-02-2013, 02:57 PM

Hi ToastyX,

I'm running a hackintosh, which is a PC that runs Mac OS: Mountain Lion. I'm wondering if I can overclock on a Mac OS. I've noticed that all the software needed to overclock one of these monitors were all exe files (i.e., windows only).

So if you have any suggestions or ideas, please let me know.

Also, I can dual boot Mac and Windows (in the future) with two different drives, and I'm wondering if I change the settings (i.e., overclock the monitor) on the Windows OS, will it transfer the refresh rate settings to the Mac OS?

Thanks,

Kevin

***ToastyX*** · 01-02-2013, 05:28 PM

(01-02-2013 02:57 PM)ebkevinlee Wrote: I'm wondering if I change the settings (i.e., overclock the monitor) on the Windows OS, will it transfer the refresh rate settings to the Mac OS?

No.

SwitchResX is very much like CRU for Mac, but it won't overcome any driver limitations. It probably won't work beyond the 330 MHz pixel clock limit.

You might be able to get 81 Hz with the Catleap/Tempest OC monitors (or 84 Hz with the back porches reduced to 64 and 2).

ebkevinlee · 01-02-2013, 05:46 PM

(01-02-2013 05:28 PM)ToastyX Wrote:
(01-02-2013 02:57 PM)ebkevinlee Wrote: I'm wondering if I change the settings (i.e., overclock the monitor) on the Windows OS, will it transfer the refresh rate settings to the Mac OS?
No.

SwitchResX is very much like CRU for Mac, but it won't overcome any driver limitations. It probably won't work beyond the 330 MHz pixel clock limit.

You might be able to get 81 Hz with the Catleap/Tempest OC monitors (or 84 Hz with the back porches reduced to 64 and 2).

Thanks ToastyX! I'll try it and report back on what Hz I get.

NateZ28 · 02-03-2013, 10:43 AM

How high did you end up getting it to? How do you get OS X to report back the currently applied refresh rate?

ebkevinlee · 02-06-2013, 03:09 PM

(02-03-2013 10:43 AM)NateZ28 Wrote: How high did you end up getting it to? How do you get OS X to report back the currently applied refresh rate?

I've used SwitchResX and configured a custom resolution and refresh rate to 84hz. When I tried going over that (i.e., 90-120) the monitor would go black during use. As far as OS X reporting the refresh rate, I have no source other than SwitchResX as Display (under System Preferences) doesn't give me a refresh rate option.

BTW, I have a Overlord Tempest 270 OC; I don't know if the Catleaps would be different. As far as 84hz vs 60hz, I really can't tell much of a difference. Although, I hear people can tell a difference between 120hz and 60hz.

NateZ28 · 02-09-2013, 04:41 AM

(02-06-2013 03:09 PM)ebkevinlee Wrote:
(02-03-2013 10:43 AM)NateZ28 Wrote: How high did you end up getting it to? How do you get OS X to report back the currently applied refresh rate?

I've used SwitchResX and configured a custom resolution and refresh rate to 84hz. When I tried going over that (i.e., 90-120) the monitor would go black during use. As far as OS X reporting the refresh rate, I have no source other than SwitchResX as Display (under System Preferences) doesn't give me a refresh rate option.

BTW, I have a Overlord Tempest 270 OC; I don't know if the Catleaps would be different. As far as 84hz vs 60hz, I really can't tell much of a difference. Although, I hear people can tell a difference between 120hz and 60hz.

I did get it to work by overriding the EDID. The Display options in the Apple control panel report back 84Hz after doing this.
Switching back and forth I do notice a difference, even with just a 24Hz increase.

ebkevinlee · 02-09-2013, 04:46 AM

How do you override the EDID?

NateZ28 · 02-09-2013, 07:26 AM

On the Display Information pane check the Box that says Frequency Range. This will override the EDID and pixel clock limits imposed by it to your own settings.
The pixel clock is still limited to 330 MHz by the driver though.

ebkevinlee · 02-09-2013, 07:44 AM

(02-09-2013 07:26 AM)NateZ28 Wrote: On the Display Information pane check the Box that says Frequency Range. This will override the EDID and pixel clock limits imposed by it to your own settings.
The pixel clock is still limited to 330 MHz by the driver though.

I checked this in SwitchResX and I still don't get a refresh rate setting under system preferences. Here are my settings:

Frequency range (checked)
Vertical Frequency range: 10 - 200Hz
Horizontal frequency range: 15.00 - 150.00 kHz
Pixel Clock: 15.00 - 330.00

Default Resolution (checked)
2560 x 1440 @ 84 Hz

Custom Resolution:
Use simplified settings (checked): GTF
Pixel clock: 448.80
Interlaced (unchecked)
Horizontal: 2560
Vertical: 1440
Rest are default except Scan Rate for vertical is set to 84Hz and 126.924kHz for Horizontal
Positive sync (checked) Horizontal
Positive sync (unchecked) Vertical

I would love you feedback on how I could improve these settings. Also thanks for the heads up on the EDID.

***ToastyX*** · 02-09-2013, 12:11 PM

(02-09-2013 07:44 AM)ebkevinlee Wrote: Custom Resolution:
Use simplified settings (checked): GTF
Pixel clock: 448.80

That's the problem right there. You need to keep the pixel clock under 330 MHz.

Don't use GTF. That's for old CRT monitors. I thought it was going to fill in the monitor's current settings by default. You need to use CVT-RB, then uncheck "Use simplified settings" and set the back porches to 64 and 2. That will let you use 84 Hz while keeping the pixel clock under 330 MHz. Then you should be able to set 84 Hz in System Preferences.

You didn't see a difference because it was still using 60 Hz, but that doesn't explain why you were getting black screens.