View Full Version : Anyone using KMS?

January 27th, 2010, 12:08 AM
Has anyone here used systems with KMS before?
Is it supposed to affect the boot only, or also the actual desktop?
I have two computers and one has KMS enabled (it has an intel graphics card).

I've noticed that all the graphics on it look significantly crisper and sharper, to the point in which I get annoyed when looking at the other computer. I thought it was because of KMS but then after closer inspection, realised that it has a HD screen.

Is anyone able to confirm whether KMS is what is making things radically different or is it merely the screen?

January 27th, 2010, 12:20 AM
Used it on Fedora, worked great, especially when you upgrade mesa it makes the FOSS ATi driver impressive.

January 27th, 2010, 12:21 AM
Yeah, I'm thinking of either installing fedora on my nvidia comp or upgrading the kernel.

January 27th, 2010, 12:22 AM
It's nice, but it annoys me to no end when udev loads and it changes screen resolution mid boot.

January 27th, 2010, 12:46 AM
The next kernel or two should have KMS pretty well mainstream with any luck.

January 27th, 2010, 01:05 AM
The new one .33 has it. And even though lucid is getting .32, its being backported so that lucid will have nouveau.

January 27th, 2010, 01:15 AM
Works great on Fedora with an intel card

January 27th, 2010, 01:17 AM
Is the difference significant?

January 27th, 2010, 01:29 AM
Is the difference significant?

For the bootscreen, yes.

January 27th, 2010, 03:49 AM
I found (on ATI* atleast) it offers performance at the cost of stability, I had to disable it completely^ for fedora and am having a love/hate relationship atm, everything was fine for a while, but then an update introduced a crash that happens at a random point after boot (usually 10s of minutes).

*I have an RS482 chip though which is particularly ugly to code for

^The nice thing is that it is really easy to disable so while I currently don't have any compositing it doesn't make my machine unusable.

Is the difference significant?
For open drivers (intel, radeon, nouvea) yes, KMS is required for DRI2, on my machine this means:

1.5-2 times the fps in glxgears
support for more opengl features
kwin compositing will work

If you use closed drivers (flgrx or nvidia) then probably not

January 27th, 2010, 04:01 AM
KMS is what allows my laptop to load into X. Without, it's a hard crash every time.

I got a good laugh at the people who say that the "forced" switch to native mode resolution annoys them when the overriding majority of Ubuntu users rarely even see a VC or boot text. KMS is highly desireable if it causes no adverse effects.

January 27th, 2010, 05:28 AM
Been using it for months, and it's great (Intel i915.) Basically, you can switch between VTs instantly. (But it won't cure cancer and fix your air conditioning, either.)

January 27th, 2010, 05:53 AM
VTs? what do you mean?

January 27th, 2010, 05:56 AM
VTs? what do you mean?

Virtual Terminal/Virtual Console. If you're in Ubuntu, hit ctrl alt F1 and you'll see one. Also hit alt-f7 to go back.

January 27th, 2010, 06:05 AM
oh, I've used those before, but I never knew what they were called.