[ut2004] Tuning guide?

[Gian Paolo Mureddu]

Peter Hoff wrote:

>>
> I don't know if my friend had DMA enabled or not, but I certainly do.
>
> As for GeForce Linux drivers, Nvidia has always had better Linux 
> support than ATI. And yes, all the Open GL games run. How their 
> performance compares I don't know, UT is the only game I see played on 
> both platforms.
>
True, as of right now nVidia has better overall hardware support for 
Linux than ATi does, including features (I'm an ATi user and have been 
using Linux since 1996, so I know about this stuff).

You said your performance with a 3000+ Athlon and a 5900 is not that 
impressive in Linux? Hmm... A friend of mine who has a 5900 also had 
problems with it. Recently he reseted his Ti4600 and performance was 
astonishing... Maybe the problem is with the drivers, to some extent?

For those of you who own an nVidia cards, there are a few points 
(besides the already posted SBA/FW tweak that you can use to tweak your 
Linux performance. As far as I know, there are differences in 
performance according to the driver set that you use. For those FX 59x0 
users, the problem may be that you are forced to use a driver <= 4496 
because support for the 5900 was first introduced in those drivers. 
Having into account these differences in performance between nVidia 
driver releases. I know (from nvnews) that the set originally developed 
by PNY: the mighty 4620 driverset is the fastest (besides being the 
first to introduce the nVidia control panel in Linux). You can get that 
driver either for 2.4 kernels or 2.6 from www.minion.de, definitely I'd 
suggest you use a 2.6 kernel (I upgraded my kernel from the FC1 2.4.22 
based one since early test series, and never looked back). Performance 
in 2.6 kernels is generally faster, mainly due to the new scheduler and 
better priority handling, so your games will get better CPU raw power. 
Another thing that (I don't think has been already mentioned) is the AGP 
driver you use. The kernel's AGPGART (the external for us ATi users) 
driver tends to be faster, but may crash (badly) when you use either SBA 
or FW. The NVGART (the internal for us ATi users) driver tends to be 
more stable at the cost of speed, however some chipstes are not 
compatible with this driver and you are forced to use the kernel's AGP 
driver. This tweak may expose one flaw of the nVidia drivers though: X 
may hang disabling any input (no ctrl+alt+F1 or del) except for the 
mouse (when it's a USB mouse). The system is not dead, but you'd have to 
remote access the computer and shut down X to regain the system. However 
some say that doing this and not rebooting will make these hangs more 
frequent. I've seen (and experienced) these hangs with my friend's 
5900FX and the 4496 drivers while using the external AGP driver. 
Switching to the internal driver, will make these problems go away or at 
least they will not appear so easily. AFAIK the latest (or 5336) 
driverset is quite slow compared to the 4620 and 4496 ones.