rec.autos.simulators

Wheels use too much CPU!!!

Grant Reev

Wheels use too much CPU!!!

by Grant Reev » Tue, 02 Jun 1998 04:00:00


>   I started driving GPL with my joystick so I didnt have to change to it when
> I played flight sims and the fact that my T2 was using too much CPU.I have
> since gotten a Voodoo2 and GPL rocks at 1024by768 on my 21in monitor with
> fluid frame rates,its enough to make me consider a TSW:)(also that N3 and
> Cart3 are due soon).With that said,I went and hooked up my T2 again.My frame
> rates dropped what seemed like 10fps.The reason I am writing this post is that
> I wanna know if anybody else has this experience with the T2 and if its like
> this with all wheel units.I really would like to know why this happens as
> right now the only reason I can think of is that the T2 uses a 150k pot.Anyone
> here know about how joystick polling works??????

I think this is a fairly common occurance. I was reading some info
on a page reviewing a digital gamecard, and they pointed out that
the way an analogue joystick/wheel signal is read is to poll the
gameport repeatedly to measure the amount of resistance. The more
resistance on the axis, the longer it takes the CPU to measure it.
This amount of time is dependant on the resistance, not on CPU speed,
so having faster CPUs will take the same percentage of CPU time.
Apparently normal joysticks use around 15-25% of available CPU time
or thereabouts to measure their resistance. But, the Thrustmaster T2
is known to have the highest resistance pots of almost any controller
out there, and at highest resistance (turning the wheel all the way
to the right) can suck up to 50% of your CPU time. Well, that's what
that page said:) maybe they were exaggerating the percentages a little
so as to make their digital gamecard look good, but I wouldn't be
surprised if those values are actually correct.
The digital gamecard measures the resistances itself with much
higher accuracy than a soundcard gameport, and applies moothing
algorithms to the values to eliminate any stutter, thus freeing
the CPU of the need to waste so much time reading the joystick.
All the CPU needs to do is ask the gamecard for the latest value,
which apparently takes up less than 0.1% of CPU time. this is
a hell of a lot better than 25-50% for a T2 :)I've got a T2 myself.
I ordered one of those digital gamecards to try it out, but it
hasn't arrived yet so i don't know just how much of an improvement
it makes.
The card is a PDPI L4 digital gamecard.
http://www.racesimcentral.net/

when the card arrives (hopefully sometime this week) if it makes
a HUGE difference, i'll jump up and down a lot, be happy, and post
a message here to rave about it.

apparently you can plug 4 joysticks in at once and use them all
too. (8 with 2 cards). maybe i could build my own 10 axis and
20 button steerwheel or something:)

bye for now,
Grant.

Trevor C Thoma

Wheels use too much CPU!!!

by Trevor C Thoma » Tue, 02 Jun 1998 04:00:00


> I think this is a fairly common occurance.

Hi Grant,

This is true, we tested almost all resistance value pots with the TSW
and we found that the higher the resistance value, the lower the
framerate. 50k pots were best for FR but the degree of control was not
fine enough so we use 100k.

Trev

Tilu

Wheels use too much CPU!!!

by Tilu » Tue, 02 Jun 1998 04:00:00

hey !

cool, so we know that the higher resistance menas less frame :-(
how about these digital gamecards? any1 tried them?

Tilus

Tilu

Wheels use too much CPU!!!

by Tilu » Tue, 02 Jun 1998 04:00:00

hey !

I just tested my PC

It is a P2-233 oc. to 333
128 megs of SDram ( 7 ns )
Matrox G100 2xagp. 8 mb
Voodoo2 8mb
T2
SB16 pnp

i use the SB as a gameport !
i tested 3 different games and useing joy or keys showed 7 %  avarage frame
rate difference !
also turning the wheel or leaving centered dont show ANY frame rate
difference on my system !
also u have to note that useing software renderer, not the V2 showing bigger
difference ( about 10-12% ), this is couse V2 takes the job of the CPU, so
it has more time to mess whit T2( i think ).

best regadrs,
Tilus

sorry for the BAD english...

Henderso

Wheels use too much CPU!!!

by Henderso » Tue, 02 Jun 1998 04:00:00

Would A digital gamecard mean one of those thrustmaster ACM cards....is
that a digital gamecard....I have one I just don't use it because I
though it was causeing my joystick not to work through my
joyswitch...but I have since found out that my joystick is fried.....but
my wheel and gamepad work fine....by the way anyone have a good
recommendation for a joystick????

                                                        Nate


> hey !

> cool, so we know that the higher resistance menas less frame :-(
> how about these digital gamecards? any1 tried them?

> Tilus

Tilu

Wheels use too much CPU!!!

by Tilu » Tue, 02 Jun 1998 04:00:00


>Would A digital gamecard mean one of those thrustmaster ACM cards....is
>that a digital gamecard....I have one I just don't use it because I
>though it was causeing my joystick not to work through my
>joyswitch...but I have since found out that my joystick is fried.....but
>my wheel and gamepad work fine....by the way anyone have a good
>recommendation for a joystick????

>                                                        Nate

i dont think ACM is digital...is it?

btw there is some PCI sound cards that has digital gameport !

Tim - fusio

Wheels use too much CPU!!!

by Tim - fusio » Tue, 02 Jun 1998 04:00:00


>when the card arrives (hopefully sometime this week) if it makes
>a HUGE difference, i'll jump up and down a lot, be happy, and post
>a message here to rave about it.

There was a thread regarding this in the flight-sim newsgroup.
After it was reported on a flight sim website that substantial
framerate differences could be garnered with the card, messages
started showing up in the newsgroup that maybe the results in the web
page were not exactly easy to duplicate.

Results varied widely, some getting a slight improvement, some getting
no improvement, and nobody getting the improvement stated on the page.
I wish I had kept the link to the article, but unfortunately I didn't.
I thought it was on www.combatsim.com, but I went back and I couldn't
find the article. Maybe someone else remembers.

--

 http://www.users.fast.net/~fusion1
 (dirt bikes, rat bikes, rental car abuse...)

Tim - fusio

Wheels use too much CPU!!!

by Tim - fusio » Tue, 02 Jun 1998 04:00:00


I dug around and found it.

http://www.combatsim.com

Go to the Recent Articles section at the bottom of the page, and read
the article on the L4 Digital Gameport.
Deja News should be helpful in finding the subsequent newsgroup
thread.

--

 http://www.users.fast.net/~fusion1
 (dirt bikes, rat bikes, rental car abuse...)

Extract

Wheels use too much CPU!!!

by Extract » Tue, 02 Jun 1998 04:00:00


>  I started driving GPL with my joystick and the fact that my T2 was using too much CPU.
> have since gotten a Voodoo2 and GPL rocks at 1024by768 on my 21in monitor with
>fluid frame rates.  .With that said,I went and hooked up my T2 again.  My frame
>rates dropped what seemed like 10fps.

Hey maybe the problem is that you need to reduce the resolution of
your game?  Even with a kick-ass card like the Vodoo 2, your
resolution is so high that frame rates will drop when the CPU is
taking care of something else.  How about droping to 800 x 600 and
seeing how your fps are?  If the choice were up to me between 1024x768
with a joystick or 800 x 600 (even 640 x 480) with a wheel,  I'm
taking the wheel anyday.

Ex

David G. Marti

Wheels use too much CPU!!!

by David G. Marti » Wed, 03 Jun 1998 04:00:00



> > I think this is a fairly common occurance.

> Hi Grant,

> This is true, we tested almost all resistance value pots with the TSW
> and we found that the higher the resistance value, the lower the
> framerate. 50k pots were best for FR but the degree of control was not
> fine enough so we use 100k.

> Trev

My T2 uses 100K Ohm pots.  I've tried 200K Ohm pots because I can't find
a supplier for 100K Ohm pots.  I got one from Thrustmaster and it is
probably half gone.  If anyone knows of a supplier, please post that
information.

David Martin

Trip

Wheels use too much CPU!!!

by Trip » Wed, 03 Jun 1998 04:00:00


> If anyone knows of a supplier, please post that
> information.

> David Martin

Why not buy the good pots right from TSW?

Trips


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