On Fri, 12 Mar 2004, [iso-8859-1] Méghazi Fabien wrote: > > > I made a modeline using http://xtiming.sourceforge.net/ > > > Modeline "336x240@60" 6.44 336 368 392 424 240 245 248 253 > > > > I don't know of any PC video hardware that supports pixel clocks that > > low. > > But where does reside this limitation ? How is it possible that a gfx card has > a minimum pixel/seconds limitation ? The arcadeVGA is able to do very low > pclock : http://www.ultimarc.com/avgainf.html > This gfx card has been designed for the purpose I have. But I wonder to know > what is different from other cards? Is the pclock limitation written in the > bios ? Is there a way to force X to use lower pclock than 12.0 even if it > says that the gfx card range is 12.0 - 350 Mhz ? Looking through CalcVClock() in the nv driver, it looks like 8 MHz is the lowest clock it can generate. You can hack the driver to allow down that low. They probably won't work very well though (noisy). In my opinion, NVIDIA's clocks are dicey even at the advertised 12 MHz minimum. Maybe you can lower the lower bound "(Freq >= 128000)" in the calculations to see if you can get a lower clock than that out if it. You're definitely driving it out of spec at that point though. Changing that to 100000 would be what's needed to allow a 6.44 MHz clock. Mark. _______________________________________________ XFree86 mailing list XFree86@xxxxxxxxxxx http://XFree86.Org/mailman/listinfo/xfree86
