At the beginning of the Raspbian, feel the system is good, is the resolution can not be adjusted, online to find a lot of solutions, tinkering for almost a day, still no solution.
During the attempt to change several systems, such as RASPBMC, Xbian and so on, finally tried the next Pidora, found that pidora under the normal, but the resolution of 1024x768, rather than I this monitor 1440*900, so think of the relevant configuration modified under, can be normal to 1440*900.
Finally try to Pidora in the Config.txt file back out, simple modification (comment out some unwanted configuration), re-brush back to the Raspbian system, and then copy the configuration file back, the miracle appeared, this goods unexpectedly also normal to 1440*900 resolution display.
Finally post the relevant configuration:
Hdmi_force_hotplug=1disable_overscan=1hdmi_drive=2hdmi_group=2hdmi_mode =47 Hdmi_ignore_edid=0xa5000080
Where the value of Hdmi_mode needs to be modified according to its display resolution and refresh rate, can be viewed by the following command:
Tvservice-m DMT
There is the same situation can try to do the above, I hope to help you.
The resolution is always 640*480 cannot be modified after the Raspberry Pi is transferred through the HDMI-VGA