Xorg VS Xvesa (in terms of performance)

[Zendrael]

Hi all!

We know that Xvesa is much lightweight than Xorg in therms of size and loading, but, wich one will get better performance on the same hardware: Xvesa or Xorg (with the apropriate driver)? And wich one has less consuption (to give more time on the batteries of a netbook)?

Thanks again for the quick answers!

[curaga]

Xorg with a native driver is always faster than vesa. You'll also get some perks like 3d and video acceleration.

Power consumption can be one way or the other; if the card is smart, stays in its lowest speed, and shuts down unused units, vesa could use less power. On the other hand, vesa does not have any power management, so on a different card the native driver may use less power. Measure with powertop if you don't have a wattmeter.

[tinypoodle]

Xorg with a native driver is always faster than vesa.

Not so at all in my perception.
Perhaps we should define speed related to what specific tasks when comparing?
To me Xorg seems to be significantly slower in many everyday routine tasks, e.g. switching between windows; switching between desktops; switching between X and console and vice versa.
Not sure if my particular way of usage might play a role there.
Note: the (newer) Xvesa extension falls in between Xorg and Xvesa from base there.

EDIT: All my references rely on my experience being limited up to TC 2.10 and the respective Xservers and kernel(without KMS).

vesa does not have any power management

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xset s ...could be used even in Xvesa to blank screen after a defined idle time

[curaga]

Not so at all in my perception.

OK, let's redefine that as a well done driver

Do you have a thread on this somewhere? If you're talking about the Intel 945, it should not be slower.

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xset s ...could be used even in Xvesa to blank screen after a defined idle time

That's fake, like the black screensaver in the console. It only draws black, it doesn't shut down the screen or gpu.

[tinypoodle]

Not so at all in my perception.

OK, let's redefine that as a well done driver

Do you have a thread on this somewhere? If you're talking about the Intel 945, it should not be slower.

No other thread, but jumped in here on opportunity 
Yes, specifically an Intel 945 (and lacking opportunity to compare with different hardware at the moment)

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xset s ...could be used even in Xvesa to blank screen after a defined idle time

That's fake, like the black screensaver in the console. It only draws black, it doesn't shut down the screen or gpu.

Agreed. However, the backlight gets turned off which could significantly save energy (when even reducing brightness to the minimum needed could prolong battery life).
BTW there is a difference (at least with defaults) that in console the screen gets just blanked with backlight staying on, as opposed to Xvesa.

[curaga]

Is it still slower when running 3.x, Xorg 7.5, KMS?

[tinypoodle]

Couldn't tell...
On TC 2.10 here (therefore refering to Xorg 7.4) and not having any experience with KMS at all.

[curaga]

Even Intel's old stack should be faster than vesa, and their efforts for a while have gone only toward the new stack.

[tinypoodle]

ok, here a specific case:

• 15 windows of opera10 on desktop 1 and two more on desktop 2
• wm = jwm-snapshot
• cloud mode, no swap involved (therefore reads and writes to disk could be excluded as a parameter of speed)
• X resolution 1024x600 (native, needs 915resolution for Xvesa), framebuffer resolution 800x600

Xorg is significantly slower than Xvesa of base with:

• switching between the 15 windows on same desktop
• switching between desktop 1 and desktop 2 which both have an opera10 window in foreground
• switching from framebuffer console on tty1 to X on tty2
  

[curaga]

Would you like to try the latest stack?

Something like
- boot 3.0 live cd "tinycore text base norestore"
- tce-load -wi Xorg-7.5-3d
# FB transform as KMS takes over
- startx & test

With KMS you would get a native resolution fb, and near-instant VT switch at the very least.

[tinypoodle]

Thank you very much for your instructions 

Unfortunately due to my individual particular circumstances not easy to try out what you suggest at the time being. 

However little i have read about KMS, I could imagine you are right about what to expect.
BTW, with Xvesa (base or extension) in fact i do have near-instant VT switching already 
What concerns native resolution fb of 1024x600 on Intel 945, see also http://forum.tinycorelinux.net/index.php?topic=6887.msg36786#msg36786

P.S.: added "EDIT:" to reply #2 to reflect the development of this thread and put my statements in an adequate perspective.