Precisamos saber como é sua placa de vídeo.
Execute sudo lshw -C video e cole o resultado aqui.
Resposta lshw C vídeo > *-display UNCLAIMED
description: VGA compatible controller
product: VT8375 [ProSavage8 KM266/KL266]
vendor: S3 Inc.
physical id: 0
bus info: pci@0000:01:00.0
version: 00
width: 32 bits
clock: 66MHz
capabilities: pm agp agp-2.0 vga_controller bus_master cap_list
configuration: latency=32 maxlatency=255 mingnt=4
resources: memory:ed000000-ed07ffff memory:e0000000-e7ffffff memory:ec000000-ec00ffff