slow virtual consoles with KMS

[cyberjun]

Hi,
I am running gentoo-sources-2.6.33-r1 on a dell D510 laptop with intel graphics. I have enabled KMS and thus framebuffer. Everything is working fine except the VCs. The switch from X to VC or vice versa is fast (as promised by KMS). However the VCs are slow in rendering text.

From gnome-terminal:

[Ant P.]

Unless someone decides to push X's 2D accel code into the kernel, it's always going to be slower.

[dmpogo]

It is not KMS per se. I use vesafb with high-rez mode and no KMS, and my numbers are almost identical to yours. Lack of acceleration shows. (I think I remember intelfb had some 2D acceleration, but it got rusted away)

[M]

vesafb is not accelerated, fb drivers for specific cards are, but it seems like those are not touched for years. But I tried nouveau many times and lately with kms, I didn't time it but fb seems much much faster then vesafb and mplayer works really good, I think kms should be accelerated. My guess is that something is wrong with intel drivers.

I remember how good it was when I used matrox video card with fb driver and kernel driver for mplayer (one of main devs had matrox card ) , I think that analog tv with mplayer in framebuffer had better quality compared to X. I now have old t20 with savage card and it surprises me how fast it is when switching VC, I also saw huge difference between savagefb and vesafb (savagefb is faster but not so usable).

[Rexilion]

The threadstarter has an accelerated framebuffer, I'm sure of that. I mean, if you used a standard VGA terminal it could have taken minutes for that action to complete. I think that userspace terminals like xterm, gnome-terminal et all also skip large chunks of text: they just display it once and then move over to the next. The VC slides no matter how much you put in it which causes it to take a little longer...

[M]

Maybe disabling the VGACON_SOFT_SCROLLBACK can help a little bit, this option uses system ram instead of vga ram but slows down console.

[Rexilion]