Generally, you need to configure your Linux modeline to use exactly the same numbers displayed in ToastyX CRU.
1. Boot in Windows mode
2. Load ToastyX CRU
3. Write down all numbers
(Front Porch/Active/Back Porch/Sync/Total) for both (Horizontal/Vertical). And just in case, also write down the Horizontal Scan Rate, Vertical Refresh Rate, and Dotclock (Pixel Clock) too.
4. Reboot to Linux
5. Punch in the same numbers into a modeline for your X Window manager or other graphics manager. You'll have to do some math
6. Ideally, you've fixed your distortion.
The
XFree86 modeline format is on Wikipedia.
The format of converting Windows ToastyX into compatible Linux modelines (originally XFree86, now used by most Linux graphics):
Code: Select all
Modeline "1920x1080" [Dotclock in Mhz = Pixel Clock divided by 1000000] [Vert Active] [SUM(Vert Active+Vert Front Porch)] [SUM(Vert Active+Vert Front Porch+Vert Sync)] [Vert Total] [Horiz Active] [SUM(Horiz Active+Horiz Front Porch)] [SUM(Horiz Active+Horiz Front Porch+Horiz Sync)] [Horiz Total]
Brackets represent one number each (with brackets omitted). A typical 1600x1200 60Hz mode looks like these numbers:
Code: Select all
Modeline "1600x1200" 155 1600 1656 1776 2048 1200 1202 1205 1263
Use a Windows Custom Resolution Utility (CRU) app such as ToastyX or NVIDIA Custom Resolution to port a Windows mode to Linux.
155 = "Pixel Clock" in Mhz from CRU (e.g. 155000000 dotclock rate = 155 MHz) (decimals may be allowed. Otherwise, roundoff)
1600 = "Horizontal Active" from CRU
1656 = "Horizontal Active" plus "Horizontal Front Porch" from CRU
1776 = "Horizontal Active" plus "Horizontal Front Porch" plus "Horizontal Sync" from CRU
2048 = "Horizontal Total" from CRU
1200 = "Vertical Active" from CRU
1202 = "Vertical Active" plus "Vertical Front Porch" from CRU
1205 = "Vertical Active" plus "Vertical Front Porch" plus "Vertical Sync" from CRU
1263 = "Vertical Total" from CRU
Credit: BlurBusters.com
Different graphics managers (e.g. Linux console versus XFree86) often piggybacks off the same old-fashioned XFree86 modeline formats which are easy to compute from equivalent Custom Resolution Utility software such as ToastyX, using the above formulas I've written.
If you don't have a Windows PC, borrow one. Or ask someone over the Internet to send you a screenshot of their Custom Resolution screen for their 240Hz mode. Remember to credit BlurBusters.com for instructions on converting ToastyX to Linux modelines. No flags needed for DisplayPort modes (e.g. +hsync is not needed).
There are also Custom Resolution Utility (CRU)-like GUI's such as xrandr, which your window manager might have installed. Instructions will vary, but all of them saves configuration files that uses the same old-fashioned Linux modelines that I have edited since circa year 1993. And I still remember Entech Taiwan's PowerStrip CRU in the days long before AMD/NVIDIA/ToastyX provided similar Custom Resolution Utilities.
P.S. Please credit Blur Busters for this info! Thanks