Christopher Crawford wrote:Are you guys multiplying by 10 or is my hardware just a whole lot slower?
William M. Quarles wrote:Well, then my results are too low too. I have X4.3 w ati.2 @[EMAIL PROTECTED] kernel 2.4.23 and I only get ~1400 FPS with glxgears
William M. Quarles wrote:What frame rate do you get from glxgears?? Please include resolution and color depth.
Vladimir Dergachev wrote:
-the AGP bandwidth problems are not an XFree86 bug, but are a GATOS bug,
right? Because I only have problems with display speed when using the
GATOS drivers.
-I've got a Pentium III, so it is not just an Athlon/Duron problem.
No, GATOS code does not mess with AGP or mtrr. There was some issue with
mtrr settings - whereby the framebuffer region was not properly marked,
this manifested (due to different causes) with both Athlons and Pentiums.
I don't remember the details..
However, I would have expected that this has been fixed in new kernels.
best
Vladimir Dergachev
There was an issue with Athlon/Duron AGP bandwidth issues that arose in
Xfree 4.3.0, and was unaffected by GATOS drivers. A later kernel update
made it a bit better, but I do still get better xv throughput on my PCI
Rage128 card, than my AGP(4x) Radeon8500 card. The AGP bandwidth issue
affects only Athlon systems using older <=266 MHz chipsetsmade by Via,
and does not affect DRI bandwidth.
It sounds as if your problem is something different.
If remember right the problem was that AGP space and framebuffer space
could both be referenced by CPU in more than one way. It had something to
do with O_SYNC flag being added when opening /dev/mem which effectively
turned off mtrr settings. The problem was first noticed on Athlons, but
then a similar effect was noticed with Pentiums.
XFree86 4.2.0 does not exhibit this problem because (AFAIK.. ) it did not
use O_SYNC flag when opening /dev/mem.
My understanding is that with O_SYNC flag we describe two kinds of behaviour: when data is written right away and when the write can be delayed by the kernel.
However, with mttr the meaning of "written right away" splits in two parts
"written right away, even a single byte" (used for access to registers)
and "written right away, grouped into blocks for fast transfer" (used for
access to framebuffer memory). Note that grouping into blocks is done by
the hardware, not the kernel.
So, when XFree86 4.3.0 uses O_SYNC flag to open /dev/mem l-k sets mtrr to
"written right away, even a single byte" and direct writes to framebuffer
(as needed for transfer of Xv images) become a lot slower.
Now that I have written all this it occurred to me that I too seen some
slowdown after installing GATOS drivers. It might be that whatever
workaround is employed breaks when GATOS reprograms the memory controller
on Radeons. Now how this could happen I have no idea, as Radeon memory
controller is completely separate from mtrr.
Could someone correct me please ? (CC'd to [EMAIL PROTECTED])
best
Vladimir Dergachev
I noticed the slowdown most profoundly on this 3D game called Chromium. It acts like I'm not getting acceleration. DVD playback was also a bit finicky. I'm using an ATI All-In-Wonder Radeon. Then again, I'm also using the Red Hat kernel. Although this kernel variant generally performs better because of low latency patches and 2.6 DRM, may not be 100% GATOS friendly. I'll try the latest standard 2.4 kernel and report.
Peace, William
I tried the standard Linux kernel with the GATOS drivers, and there was no improvement in graphics performance over using the Red Hat kernel and the GATOS drivers. 2D graphics are slow, 3D graphics are ridiculously slower. The drivers included with the kernel packages work much better. Something is definitely wrong with the GATOS drivers for XFree86 4.3.
Peace, William
I get 2400fps (default) with X4.3 w/ati.2 @ [EMAIL PROTECTED] [EMAIL PROTECTED]@24bpp.
AthonXP 1700+ w/512MB DDR & 4x AGP AiW Radeon8500DV
My system is AthlonXP [EMAIL PROTECTED] + Radeon 8500LE
How do I check if I have this problem with AGP bandwidth?
With the GATOS drivers, I'm getting around 170 fps. With the Red Hat drivers, I'm getting around 798 fps. So there is definitely more than a significant slow-down in the GATOS drivers.
Pentium III 1.1 GHz (100 Mhz FSB), 256 MB ECC SDRAM, ATI All-In Wonder Radeon AGP running at 2x, 1024x768 24 bpp.
Peace, William
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