Re: [Flightgear-devel] Graphics cards

[Stefan S. <ni...@de...>]

Hi Curt,

On Wednesday 29 January 2014 15:13:53 Curtis Olson wrote:

> I would love for more users to step forward and contribute positive stories
> that they were able to get FlightGear running well on linux using 100% free
> drivers.

I just added my case (Radeon HD 5670) to the supported cards list in the wiki. 
I'll probably soon add another case. Since the free drivers have finally 
caught up, it's starting to make sense to buy some beefier hardware.

> I have seen evidence that the open-source 3d graphics driver situation is
> continually improving so hopefully we'll get to the point someday where
> typical users don't need to be bothered with this issue, but we aren't
> there yet.

I have to admit, that running the absolutely latest versions helps big time. 
With r600 generation hardware (like my HD 5670) it's been working very well 
for about half a year, so the latest distribution versions should be fine. 
With the newer radeonsi driver one needs to go a little further (which for 
example on openSUSE is very simple). So all that's left is waiting for 
distributions to pick up the latest versions and users to upgrade their 
distributions. But that's only a matter of months now instead of years.

> If anyone out there is a linux kernel developer and understands the guts of
> ati/amd, intel, and nvidia video cards and wants to push the open-source
> driver capabilities and speed, you have our full support.

A suggestion: a thing FlightGear developers could do to help developers of the 
free drivers, to help themselves, to help users and to help the Phoronix 
website would be to implement a benchmark mode. Phoronix is desperate to find 
more up to date and graphically challenging games for their benchmarks. The 
driver developers do read Phoronix and use the Phoronix benchmark suite to 
optimize the drivers. Users make buying decisions based on these benchmarks 
and general reports and last but not least, you know best how difficult 
performance optimization is for an application developer.

I played around with the existing capabilities last weekend and it looks like 
we're almost there anyway. Setting FG_HOME to a temporary directoy ought to be 
enough to prevent leaking settings from one run to another and allows using 
specific settings for the benchmark run (e.g. Rembrandt/ALS). Using generic 
file input allows replaying a full flight and the telnet interface allows 
reading FPS and frame distance numbers. The script at 
https://github.com/flighten/test attempts to do so anyway. Combined with some 
static weather input and fixed random seeds (probably supplied on the command 
line) we'd have all we need for reproducible benchmarks.

If any developer finds some time to implement the missing pieces this could 
help tremendously. My personal situation will improve in about half a year, 
but if someone can pull this off before that, we'd not only get better support 
but also great marketing. FlightGear would very probably be featured in every 
Phoronix benchmarking article and those are very frequent.

Stefan