1)this the output for lspci -v of the graphic card that shows that there is no kernel driver in use: 01:00.0 VGA compatible controller: NVIDIA Corporation GF108 [GeForce GT 630] (rev a1) (prog-if 00 [VGA controller]) Subsystem: ZOTAC International (MCO) Ltd. GF108 [GeForce GT 630] Flags: bus master, fast devsel, latency 0, IRQ 10 Memory at fd000000 (32-bit, non-prefetchable) [size=16M] Memory at f0000000 (64-bit, prefetchable) [size=128M] Memory at fa000000 (64-bit, prefetchable) [size=32M] I/O ports at dc00 [size=128] Expansion ROM at fe980000 [disabled] [size=512K] Capabilities: [60] Power Management version 3 Capabilities: [68] MSI: Enable- Count=1/1 Maskable- 64bit+ Capabilities: [78] Express Endpoint, MSI 00 Capabilities: [b4] Vendor Specific Information: Len=14 <?> Capabilities: [100] Virtual Channel Capabilities: [128] Power Budgeting <?> Capabilities: [600] Vendor Specific Information: ID=0001 Rev=1 Len=024 <?> I know that nvidia driver will solve the issue, but for one side I fear the nvidia driver installation will not be successful and make trouble for the system...I will try with the suggestions you gave, in fact there is a lot of discussion on google thanks 2)here some outputs of the link you sent me: bash-4.3# cvt 1680 1050 # 1680x1050 59.95 Hz (CVT 1.76MA) hsync: 65.29 kHz; pclk: 146.25 MHz Modeline "1680x1050_60.00" 146.25 1680 1784 1960 2240 1050 1053 1059 1089 -hsync +vsync bash-4.3# bash-4.3# xrandr --newmode "1680x1050_60.00" 146.25 1680 1784 1960 2240 1050 1053 1059 1089 -hsync +vsync xrandr: *Failed to get size of gamma for output default* 2015-01-20 21:23 GMT-02:00 Bryan Bennett <bbenne10@gmail.com>:
What X driver are you using? I seem to remember that the vesa/VGA drivers only supported 4:3 ratios or something like that, which might explain this behavior. If you're using Intel or similar, it might be that your EDID info is not being reported properly (or something doesn't know how to read it correctly. I can't really say). This[1] explains how to add undetected resolutions. Google also had much more info.
1: https://wiki.archlinux.org/index.php/xrandr#Adding_undetected_resolutions
-- * Cezar Rangel* *cezar.rangel@gmail.com <cezar.rangel@gmail.com>*