gamedevlists-windows

RE: [GD-Windows] More timer fun!

[brian h. <bri...@py...>]

> Anyone mind if I summarize and send this all to an internal MS alias
> with a bunch on kernel gurus on it?  I'll see what I can find...

This is a public list, so feel free.  It would be very, very nice if 
there was a final, authoritative, reliable way to handle timing on all 
Windows platforms.

Sounds like Jon Watte has this figured out, but he's not sharing =P

Brian

RE: [GD-Windows] More timer fun!

[Barstow J. <JBa...@uk...>]

Perhaps we could persuade gfx card manufacturers to add a decent high
precision low latency clock to their cards.
Could be exposed via D3D API or other.

Seeing as we're specifically interested in a solution for gaming and most of
us now presume gfx hardware, this seems like a reasonable solution.

Would take a while to come through but then how long has this problem
existed already (and with no signs of a practical solution) ?

Jason

Re: [GD-Windows] More timer fun!

[Javier A. <ja...@py...>]

Barstow Jason <JBa...@uk...> wrote:

> Perhaps we could persuade gfx card manufacturers to add a decent high
> precision low latency clock to their cards.
> Could be exposed via D3D API or other.

PC's lack of a way to synchronize to the vertical retrace (despite being
spec'd in EGA or VGA, don't remember) has been in place long enough that I
can't imagine something like you describe. In any case, 3D hardware is not
the place where to look for game logic timing information: the app needs
time information even if it hasn't initialized the rendering engine (think
dedicated servers), or while it's minimized (device lost), etc etc.

  Javier Arevalo
  Pyro Studios

RE: [GD-Windows] More timer fun!

[Jon W. <hp...@mi...>]

> > Perhaps we could persuade gfx card manufacturers to add a decent high
> > precision low latency clock to their cards.

> PC's lack of a way to synchronize to the vertical retrace (despite being
> spec'd in EGA or VGA, don't remember) has been in place long enough that I

Anything that sits on the other end of the north bridge is doomed to
be high latency (microsecond or worse) AFAICT.

RDTSC is the best we've got, and it works fine except on SpeedStep.
Grumble.

Cheers,

				/ h+

RE: [GD-Windows] More timer fun!

[Philip T. <pt...@wi...>]

Actually, recent Intel mobos ( ICH3 chipsets iirc, see
http://www.extremetech.com/print_article/0,3998,a=3D10473,00.asp ) do =
have
updated timer hw, and MS will support it in some future OS product I am
not supposed to mention.=20

Intel has info at ftp://download.intel.com/ial/home/sp/mmts097.pdf

Some of the reasons behind the creation of the new timer, as well as
some of our plans for its use have already been posted in the doc
Guidelines for Providing Multimedia Support on
http://www.microsoft.com/hwdev/platform/proc/mm-timer.asp

I believe this was also discussed at the recent WinHEC.

Note, AMD will support this in future mobos as well.

-----Original Message-----
From: Barstow Jason [mailto:JBa...@uk...]=20
Sent: Wednesday, September 04, 2002 2:12 AM
To: gam...@li...
Subject: RE: [GD-Windows] More timer fun!=20


Perhaps we could persuade gfx card manufacturers to add a decent high
precision low latency clock to their cards. Could be exposed via D3D API
or other.

Seeing as we're specifically interested in a solution for gaming and
most of us now presume gfx hardware, this seems like a reasonable
solution.

Would take a while to come through but then how long has this problem
existed already (and with no signs of a practical solution) ?

Jason


-------------------------------------------------------
This sf.net email is sponsored by: OSDN - Tired of that same old cell
phone?  Get a new here for FREE!
https://www.inphonic.com/r.asp?r=3Dsourceforge1&refcode1=3Dvs3390
_______________________________________________
Gamedevlists-windows mailing list
Gam...@li...
https://lists.sourceforge.net/lists/listinfo/gamedevlists-windows
Archives: http://sourceforge.net/mailarchive/forum.php?forum_id=3D555

RE: [GD-Windows] More timer fun!

[Leath M. <lea...@ep...>]

> Intel has info at ftp://download.intel.com/ial/home/sp/mmts097.pdf

Excellent -- they've thought of multi processor systems... :) Pity
the doc is two years old and there still isn't anything available...

Leathal.

RE: [GD-Windows] More timer fun!

[Jon W. <hp...@mi...>]

> The Dell problem seems to be that the time reported isn't since system
> boot, but instead some arbitrarily high number, maybe out of the BIOS
> with battery backup.

The 32 bit value will wrap around once every 4 billion milliseconds. Could
you be seeing that? If the number starts arbitrarily high, then the up time
won't need to go to a month and a half to actually reach this point...

Cheers,

			/ h+