On 19 Nov 2002, Gerhard Olsson wrote: > The modelines automatically generated by XFree86 seems to give a refresh > rate of maximum 85 Hz. You have to generate a modeline manually to > achieve a higher refresh rate. Is this intentional?
There aren't yet any truly automatic modelines in the server. xc/programs/Xserver/hw/xfree86/etc/vesamodes contains a list of (non GTF) VESA standard modes, and xc/programs/Xserver/hw/xfree86/etc/extramodes contains some other useful standard modes (many of them GTF compliant). Other than GTF, I'm not aware of any high refresh rate modelines which are part of any standard, which may explain we we don't automatically provide any. Don't forget that faster may be better for CRT, but flat-panel screens don't typically fade and need refreshing, so faster isn't really appropriate for them. A gtf modeline generator was recently added to the XFree86 CVS tree, but we don't yet use GTF modes, nor the modelines included in DDC data from many monitors. XFree86 is a member of VESA, and has the GTF spec and spreadsheet, but neither I nor anyone else has got around to adding support in the server. > A higher refresh rate than 85 Hz may be difficult to see with the eye, > but I wanted to at least try my monitor at a higher refresh rate. > > Ideally, XFree86 would always be configured to use "Optimal" refresh > rate. That would make it simple to explain to users that Optimal refresh > rate is always used. (There could be a parameter to cap the refresh rate > at 85Hz. I have heard that high refresh rates wear the > monitor even if they are within the specs, but some say this is not the > truth.) What is "Optimal" ? I think it depends on the monitor, so the best thing would be to use the info the monitor gives us in DDC data - which can include a "preferred mode". > A related issue: Is the mode lines generated by XFree86 conforming to > the General Timing Formula (GTF)as defined by VESA? Most modeline > generators on the Internet does not conform to this standard. This > creates problem for the Nvidia driver, that can handle sync pulses with > a maximum width of 256 pixels. Most VESA modelines do not conform to GTF, mostly because GTF puts the horizontal flyback starting (finishing?) halfway through blank time, which is different from where most of the previous standard modelines put it. > The only thing I know about GTF is in the only gtf compliant modeline > generator I have found. There is not much on the VESA website about GTF. > > http://www.xfree86.org/pipermail/xpert/2001-October/012070.html > or > http://www.sh.nu/nvidia/gtf.c Andy Ritger wrote those, and the gtf generator that is now in XFree86, so I assume it is the same one. -- Dr. Andrew C. Aitchison Computer Officer, DPMMS, Cambridge [EMAIL PROTECTED] http://www.dpmms.cam.ac.uk/~werdna _______________________________________________ Xpert mailing list [EMAIL PROTECTED] http://XFree86.Org/mailman/listinfo/xpert
