# How do I determine the bps for video setting in grub?

## Thomas2010

I am using http://en.gentoo-wiki.com/wiki/KMS#Forcing_a_Resolution as a guide to set my video resolution to 1024x768 when I boot but I do not know where to look to see what bps (bits per second?) I should use. It is defaulting to 1600x1200, which would not be a problem if my monitor wasn't having problems. My Xorg.0.log file can be seen at http://paste.pocoo.org/show/456879/

While I am on the subject, my manual (Hitachi SuperScan Elite 751) 640x480, 800x600, 1024x768, 1280x1024, and 1600x1200. They are all 4:3 resolutions except for the 1280x1024 which is 5:4, but in the Xorg.0.log file it gives a resolution of 1152x864, which is a 4:3 resolution. I know I can use 1024x768 without my monitors problems causing me problems, but I would prefer to use 1152x864 if I can. Is it safe to use any resolution that appears in a modeline or should I stick to what is in the manual?

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## Gusar

It's "bits per sample" and 32 is usually set here. X pretty much always uses 32.

Hmm, I see

```
[ 14078.136] (II) [KMS] drm report modesetting isn't supported.
```

in your log. What graphic card do you have exactly?

About your second question, if the display is capable of 1600x1200, I don't see a problem with 1152x864. OT: Wow, there's people who still have CRTs?  :Smile: 

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## Thomas2010

My on-board graphics card is a Radeon Xpress 200G series and my lspci -v output can be viewed at http://paste.pocoo.org/show/457276/. I tried 

```
video=1024x768-32@75
```

 and 

```
video=VGA-1:1024x768-32@75
```

but I did not get that resolution. I did, however, get either 1280x1024 or 1152x864, but I do not know the command that will display my current resolution.

If my graphics does not support KMS, what should I do? Do I just accept I do not have hardware that supports KMS and continue as usual or am I going to have to reconfigure my kernel. http://www.gentoo.org/doc/en/xorg-config.xml is what I used to configure the graphics part of my kernel.

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## Gusar

Hmm, isn't Xpress 200 that really old, really crappy thing? I have some vague recollections of an ATI chip like that. Particularly it's mobile variant.

It should support KMS though. If you have it activated in the kernel and it still doesn't work, I can't really help further, I have no personal experience with ATI graphics.

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## Thomas2010

I thank you for your help. Maybe I am missing something in my kernel. I will take a look at my kernel when I move to 2.6.39-r3 that became available this week.

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## wcg

Do you really need 32-bit color at boot? This works for

the Nouveau driver's framebuffer (nvidia graphics chip)

on a system that I have:

```

video=640x480-8@75

```

I got the dimensions and Hz ("@75") by starting X with xfce

and looking at xfce's display settings to see what resolutions

and Hz were enabled.

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