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Old 07-27-06, 06:25 AM   #18
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Join Date: Apr 2005
Posts: 86
Default Re: Opinions on driver license

Originally Posted by acreal

Actually SoftIRQs/Tasklets increase performance. Because deferring non-critical work in interrupt handlers ensures lower response times for, well, critical tasks. This is essential for network throughput.
Yes, i totally agree.
It is a question on what is called performance, and how to prioritize things.

an example (found on windows):

under certain circumstances, sound with the new X-Fi series is totaly choped.
creative says that in this cases the gfx card eats up all available memory
bandwith for huge amount of times, and the on-chip audio buffer on the
X-Fi underruns. Let's assume creative is right.

This is of course an undesirable situation for most users. BUT:

There are limited ressources (in this example memory bandwith).
The graphic cards devotes all ressources to itself, with the highest priority.
This gives more fps than if the soundcards gets enough bandwith, and
most benchmarkers don't wirte that sound w/ the X-Fi was chopped in that

If the driver was open source, somebody would fix the situation, leading to
less fps.

thats the same with SoftIRQs and tasklets. somebdy would give the sound card's IRQ a higher priority, as the soundacrd driver only directs the soundcard to a new buffer, which is less work on the one hand, on the other
hand giving complex things of the gfx driver a higher priority could make sound
choppy. The same goes with network latency as well.

The fact is that with an open source driver there would be more sort of
"balanced system performance" (hw should i call it??), whereas an closed source
driver would deliver more fps (at the expense of other things).

not that the latter is more desirable, but if you look on raw fps numbers in benchmarks ...

About GL, is it a userspace library, so you may be confusing this with DRI and DRM the framework allowing for fast and secure acces to graphic hardware (and designed to speed up GL operations).
i know of that.

i am talking about nvidias implementation, which has at least some part of the opengl core inside the kernel. (the nvidia module has 5MB!)
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