[plug] NVidia drivers and RENDER acceleration

[Craig Ringer]

> True that most people don't want
> their compilation to go slower, though, and it's bad if a terminal
> actually displays slowly because it's consuming large amounts of CPU
> time. 

And that's what's happening here. It's working so hard, on my 1.5GHz 
Athlon, to DISPLAY TEXT that the stdout buffer fills up and the compile 
job pauses blocking on output until the terminal gets around to 
displaying some more text.

> However, I find something comforting in the use of slowish
> terminals in combination with GNU screen.

I can understand that.

>>Now, if only the free XFree86 drivers (ANY of them) supported 
>>accelerated RENDER.
> 
> Why is everyone always after more speed!!

Because a snappy display is much nicer to work on. Relatively tiny 
delays, like when switching virtual desktops and waiting for an app to 
redraw, can become irritating and sometimes significant when you're 
doing it a /lot/.

Mozilla is an excellent case.

Additionally, I'm not always working on modern hardware. Accelerated 
RENDER on the s3 driver in particular would make it practical to use 
XFT2 and RENDER on a lot of older hardware. As we use s3 based P133 
xterms at work, you can imagine the interest in accelerated RENDER - I 
have found it to be the single biggest issue with application 
responsiveness on the terminals.

I've worked around it by avoiding the use of xft2 and RENDER where 
possible, and that does help, but it's still a right pain.

>>Interesting. It still takes at least a full second for my system to 
>>switch from X to a VC, and at least 1/2 a second to switch back.
> 
> OMFG 1 full second??? It takes longer than than for my CRT to switch
> resolutions! How did our forebears survive? (Seriously, though: I
> realise the point you're trying to make with the comparison to LCD
> screens, and I appreciate the fact that developers should not
> overlook sources of slowness.)

Not just that, but try switching back and forth between X and a VC, say 
to look at debugging output from something attached to the X server. 
It's a right pain - small delays can add up and be really annoying in a 
hurry.

Having used X on other platforms where it's integrated into the OS and 
uses the system framebuffer, I've been very impressed at the instant VT 
switch you get. It'd be handy - nothing more - to see this with XFree86.

So - it's not some critical show-stopper, but nonetheless a nice feature 
of LCDs. Along with not having to warm up when they get old.

As for small delays mattering - application start times are an excellent 
example of this. Click ... wait .... wait .... wait ... there we go. A 
right pain for an app that's limited function and you only /use/ for a 
second anyway - say, a mixer panel.

Craig Ringer

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