6 Replies Latest reply on Jan 22, 2015 9:15 AM by Robert_U

    1600 x 1200 @ 85Hz on VGA "exceeds the maximum bandwidth capacity"?


      Dear Great Knowledgeable Ones,


      I have a peculiar issue attempting to run an external CRT monitor on VGA at 1600x1200@85Hz with an integrated HD4200 on Win8.1 x64. The monitor's capabilities appear to be correctly recognised but Windows will not countenance running it higher than 1280x1024. Having (eventually) found the Intel custom resolutions programme I can now force 1440x1050@75Hz or 1600x1200@60Hz (the latter obviously unworkable on a CRT) perfectly happily, but attempting to enter 1600x1200 @ 85Hz or 75Hz generates the error "The custom resolution exceeds the maximum bandwidth capacity."


      This is obviously strange since not only was this perfectly normal circa 18 years ago, but this also worked fine on an older laptop with win7 x64 and i5 3210M (with Intel graphics). I do not know where to look to find out what is bandwidth-limited and why, and it would be odd if newer graphics processors couldn't cope with this. Nothing in the specifications on Toshiba's website warns of it that I could find; indeed, the only thing Toshiba says about VGA is that there is one - a clear slur to the quite literally billions of us running 15 year old monitors on a daily basis.


      Sadly I cannot revert to using my old laptop since it was lost when some friendly recent arrivals from overseas accidentally entered through the window of my flat, obviously believing it to be their own, and accidentally picked up my laptop on the way out when I asked of their intentions. Clearly the incident was so mortally embarrassing that they couldn't face returning it, hence the short upgrade cycle and therefore why I would like this to work.


      Many thanks,






      ...and before you ask, those drivers are the newest that Toshiba has on their website and Windows didn't want to update anything when attempting to install drivers from a .zip as per here:

      Desktop graphics drivers — How to Manually Install a Driver in Microsoft Windows 8* or Windows 8.1*


      Old laptop: Toshiba Satellite Pro L850-1DV, Core i5 3210M

      New laptop: Toshiba Satellite C55-A-1N4, Core i5 4200M


      Monitor: Mitsubishi Diamond Plus 220

      Displays are set to extended, 1366x768@60Hz inbuilt LCD, 1440x1050@75Hz CRT.


      Intel driver information:


      Intel(R) HD Graphics 4600