rec.autos.simulators

I ask because these cards say that they can double the frame rate of
windows native games by relieving the CPU of the need to poll the
joystick - which can take up to 50% of the CPU time so they say. Also
they are said to give unprecedented smoothness of control. Certainly a
significant plus if true but its the framerate issue that interests me
more.

If these items can do as they claim then pehaps folks like me may not
need to spend many hundreds to upgrade from P1MMXs etc to P2s. All we
need to spend is a hundred or so on a digital game card.

It'd be nioce to have this informatrion if anyone has it.

Regards

Phillip McNelley

50% is a nice example figure they use to make people think "wow!"
and run off to buy a digital gamecard:) sure, polling the joystick
COULD take 50% of the CPU - but only if the game polls the joystick
like 100-150 times per second when you are using a T2 (which has about
double the resistance of anything else - more resistance = more
poll time). But most games only poll the joystick maybe 30-40 times
per second so at worst with a T2 that might hit 15-20% of CPU usage
while the computer sits around with it's thumb up it's ass waiting
for the gameport capacitors to charge up.

If the pots in teh wheel are all at their lowest resistance positions
(on a T2 that would be turning full left, brake off, accelerator
down) then the CPU use in totally minimal. Worst is the other direction,
full right, brake on, accel off. That's when you will notice a slightly
worse framerate - ie: going into Turn 8 at the Glen (just where you
DON'T want a bad framerate!)
A digital gameport requires basically zero CPU use, so the net
effect of this is that the framerate becomes independant of your
wheel input positions - giving much smoother framerates in all types
of turns (including Turn 8!). This improves your driving fluidity.
Of course since hte CPU is now busy simlulating all the time, the
frame rate goes as fast as it can now - which is probably maybe 10-15%
or so up from what you normally see with a standard gameport.
Not the "50% speedup!" you might have thought - but it's very nice:)
Also the PDPI L4 does all sorts of cool smoothing functions on the
joystick input to *totally* eliminate jitter from your wheel's pots
(unless the pot is hell dirty - if you see jitter despite the smoothing,
your pot needs to be cleaned badly!) which *really* does make your
driving feel even better again!
so you get the bonus of a much smoother framerate - and also a much
smoother input from your wheel.

Upgrade your CPU anyway:) I have a P233mmx - it's OK for the demo,
will probably barely manage wit hthe full version - but that's not
a problem because i am going to be buying a totally new system
when i move in a month.

hmmm i can't find "nioce" in the dictionary. is that French? ;)

hope this info helps...
Grant.

Speaking for myself though I found the PDPI to be very good. Apart
from the frame rate improvement (some 10-20% on my Celeron 300), it
also eliminates "jitter" from slightly worn pots thanks to a smoothing
routine. The calibration is rock-solid, control is unchanged or
improved, and the frame-rate is increased.

If you can afford the 100 bucks it's worthwhile, although you may be
better off with a PCI soundcard which has a digital gameport - that
may work out cheaper and save you a slot into the bargain. I
understand the PDPI is quite tricky to setup with a T2 (due to 250kohm
pots), requiring some registry fiddling. It was perfect with my TSW
though. Plugged, installed drivers, calibrated and hit the track.

Cheers!
John

Phillip McNelley