4870 Xorg.conf

[zhark]

Hello!

Can someone help me with what settings should be present in the Device section (or otherwise) in Xorg.conf to make this card behave the best it possibly can?

MSI 4870 OC edition, Fglrx 8.8, Ubuntu Hardy 32-bit, Compix disabled.

The issues I'm currently experiencing is (in decreasing importance to me):

1. Random crashes. Sometimes my computer hangs instantly when loading Xorg from a fresh boot, most times not. One time it crashed when I just dragged a Nautilus window.
2. Tearing 2D and video (Mplayer with XV output, tried TexturedVideoSync, makes no difference)
3. Slow 3D performance (Quake4 feels more sluggish than on my previous 7800GT, playable though)

I've played a couple of hours of Crysis in Windows, where it runs absolutely beautifully, 1920x1200@HIGH settings (lag-free) is nothing short of stunning :-)
I'm really hoping that atleast the random crashes and video playback in Linux is fixed soon.

I'm patiently awaiting for new fglrx realeses, but in the meantime; anyone got some quick-fixes I could try?

[Zhick]

2: That's known. The only way to get vsync on video is to use the opengl-output and to enable vsync in amdcccle for everything.

Don't know about the others. But Quake4 realy shouldn't be sluggish with that monster. Maybe you could post your glxgears numbers to see if 3d is generally to slow or if it's specific to quake4? Also maybe try EXA instead of XAA or the other way around. I'm not sure what's the better choice currently.

[zhark]

2: That's known. The only way to get vsync on video is to use the opengl-output and to enable vsync in amdcccle for everything.

Don't know about the others. But Quake4 realy shouldn't be sluggish with that monster. Maybe you could post your glxgears numbers to see if 3d is generally to slow or if it's specific to quake4? Also maybe try EXA instead of XAA or the other way around. I'm not sure what's the better choice currently.

Thanks for the tip, I'll try out the stuff you mentioned tomorrow.

I tested glxgears now, I get 7500 fps with the 4870, with the 7800gt I get 12000 fps. The 4870 should be immensely more powerful than the 7800gt. But I guess glxgears can't be trusted?

[deanjo]

Thanks for the tip, I'll try out the stuff you mentioned tomorrow.

I tested glxgears now, I get 7500 fps with the 4870, with the 7800gt I get 12000 fps. The 4870 should be immensely more powerful than the 7800gt. But I guess glxgears can't be trusted?

glxgears is not a benchmark.

as mention on the unofficial ati driver wiki:

http://wiki.cchtml.com/index.php/Glx...ot_a_Benchmark

glxgears is an OpenGL program that reports FPS (frames per second) numbers. However, it is a very limited 'test'. Unlike most modern 3D games glxgears:

• has an extremely low vertex/polygon count
• does no texturing at all
• only simple, flat shading is used (except inside the hole in each gear is simple smooth shading)
• all vertex data is stored in a display list, so almost nothing passes between host CPU and video card once rendering is started. This mostly implies video card fill rate is limited. But, see next point.
• the default window size is 300x300, a large part of which is not even rendered into, so it's not even a good fill rate test
• the entire render step consists of only 21 OpenGL functions calls, of which only 6 are unique. This is not a very good OpenGL API stress test. Something like glean would be better.

So to summarize, glxgears only tests a small part of what you typically see in a 3D game. You could have glxgears FPS performance increase, but your 3D game performance decrease. Likewise, you could have glxgears performance decrease and your 3D game performance increase.

This is one of the reasons why the Phoronix Test Suite came about, to provide a reliable *nix benchmarking standards.

[zhark]

Hehe, I'll run benchmarks on both cards with the Phoronix test suite tomorrow.

[Zhick]

@deanjo: While you're right that glxgears is not a real benchmark, it's still precise enough to show you if somethings realy f*cked up.
And 7500 glxgears is way to less for a 4870. As mentioned in my first post, try switching from XAA to EXA or vice-versa.

[zhark]

Ok.
Heres what I got so far, 7800GT vs HD4870:
glxgears-> 7800:~12000fps 4870:~9000fps
PTS UT2004-Demo (ONS-Torlan, 1680x1050)-> 7800: 67fps 4870: 57fps
Lightsmark (1680x1050)-> 7800:~60fps 4870:~290fps
Quake4 (1920x1200,HIGH/ULTRA)-> 4870:~100fps (capped?)
Tremulous (1680x1050)-> 7800: 110fps 4870: 120fps

The only test the 4870 excels at are the Lightsmark test.

Do some have other suggestions for good tests that could really bring to light the benefits of the HD4870?

PS: Option "AccelMethod" "EXA" gives:
(WW) fglrx(0): Option "AccelMethod" is not used

EDIT: Linux Mint 5 32-bit, Core 2 Duo E4400@3GHz, MSI Radeon HD4870 (OC Edition), 4GB DDR2 @900MHz

[ivanovic]

Sorry to tell you, but please leave glxgears completely out of the list. It is *only* usable to see if you got "hardware accelerated DRI" at all. You will see how much fps change when you just change the windows size.

UT2004 is just CPU bound. That is: as long as you are always above something like 6ofps on average it should be fine and very playable. That is you will probably not see a change in fps when reducing or upping the resolution.

Are you sure that in Lightsmark no vsync was active for the 7800? Those numbers look strange to me, but yeah, there the 4870 should be a lot stronger.

What are your fps with Quake4 and teh nvidia card? Yes, it might be that there is a cap somewhere.

Tremulous sounds like it is perfectly playable with both cards.

Yes, fglrx does not have exa as render method, they use their own stuff (Textured2D).

What you should do to test the speed of the graphics card is activate AntiAliasing at max level in all tests. There you will reach them being graphics bound. That is at least you will get closer to it being graphics and not CPU bound. And it would be nice to get some info which CPU you were using for this comparison since it does make a difference. Nvidia seems to be better in CPU bound scenarios where ATI seems better in graphics bound ones. Don't ask me why this is the case, I don't know.

[bridgman]

One reason is probably that the ATI chips are 5-way superscalar while competing chips are scalar. It means the ATI driver has to do more work to make best use of the 5-operation instruction words, but we only need (sortakinda) 1/5th the control logic and we can use that space for more processing power.

If you look at die shots of recent ATI GPUs you see a big honkin' shader core and not much else.

[zhark]

Thank you for your input. I'll do some more testing. Yeah the numbers in lightsmark for the 7800GT was weird, vsync was not enabled in Nvidia Settings (or amdcccle) for any of the tests.
Anyways, I'm sure the Quake4 sluggishness i mentioned in my first post was a figment of my imagination. The CPU used was an E4400 clocked at 3GHz.

When vsync (xv) is fixed and it stops randomly crashing (1-2 times day) I'll be a happy camper.

Sidenote: Can someone confirm the random crashes happening, preferably with a standard HD4870 (not OC'ed)?