On Low-End GPUs, Nouveau Speeds Past The NVIDIA Driver

[Artemis3]

The 9800GT is NOT a low end.

Today I learned that my 8800GT is considered a low end GPU.

The GPU can get very hot but the only game that does so is OilRush. I know this due to a very noisy fan.

The 9800GT (8800GT and GTS 250 are the same) is NOT a low end.

For the temperature, try forcing the fan with nvclock. What i usually did to these cards, was change the firmware fan settings, so that at worse it stays at 70c instead of the 100c it will happily go if left alone. And yes, the one with the smaller (reference design) fan is noisy.

[smitty3268]

On the radeon/nvidia side, nouveau people are in the lucky position of having not freeze their API which means they can change the way the communicate with the kernel. It's not the case for radeon and if i was to write it again today i would do it completely differently.

Can't this be done by using versioning?

[calim]

Holy crap!!
I am becoming to think that nvidia GPUs, are somewhat easier to command(program) than Radeons are. I have no other explanation for this performance boost without any nvidia support, or documentation. Maybe some one of the Radeon developers will clear the situation.

They do have some helpful features, like command checking in hardware. They tell you what you did wrong instead of "crashing". Most of the time anyway.

[agd5f]

Holy crap!!
I am becoming to think that nvidia GPUs, are somewhat easier to command(program) than Radeons are. I have no other explanation for this performance boost without any nvidia support, or documentation. Maybe some one of the Radeon developers will clear the situation.

Older chips have more mature open source drivers because they've been worked on longer. The open source r300g driver beats catalyst in some tests as well:

http://www.phoronix.com/scan.php?page=article&item=amd_r500_expanded&num=5

http://www.phoronix.com/scan.php?page=article&item=ati_r500_pflipper&num=3

[MuPuF]

When using a low end card, I suppose CPU time makes up a lesser part of the overall processing time for each frame, but on a high end card, the CPU time for each frame is comparatively is much larger.

i.e if for each frame it takes 1 unit of CPU, and on a low end GPU it takes 5 GPU units, then the CPU time is only 1/6 of the time for each frame. But say on a high end GPU, it takes 1 GPU unit per frame, then the CPU time is 1/2 for each frame.

If that logic is correct then the problem with nouveau for higher end cards is that nouveau is using too much CPU.

Well, nouveau is capable of going way faster than that On my laptop (3 years old, quadro nvs 140m 128MB of vram + core duo @ 1.73GHz), I get 125fps with open arena and arround 55fps with nexuiz (not everything at the maximum, I lack vram for that).

[cruiseoveride]

When using a low end card, I suppose CPU time makes up a lesser part of the overall processing time for each frame, but on a high end card, the CPU time for each frame is comparatively is much larger.

i.e if for each frame it takes 1 unit of CPU, and on a low end GPU it takes 5 GPU units, then the CPU time is only 1/6 of the time for each frame. But say on a high end GPU, it takes 1 GPU unit per frame, then the CPU time is 1/2 for each frame.

If that logic is correct then the problem with nouveau for higher end cards is that nouveau is using too much CPU.

[MuPuF]

Did you upclock the card?

Hey Michael, did you upclock the cards? The 9800GT looks strange :s

[glisse]

If this test was CPU bound, all results including 9800GT would be pretty much the same. If the 9800GT managed to get ahead, it's because the CPU wasn't a bottleneck for any card that underperformed it.

It could still be CPU bound. For instance CPU might be able to cope up to 50fps with the gallium stack so any GPU that can't reach such framerate won't experience the CPU boundary but any GPU that can go way faster than this limit will be CPU bound.

So no, CPU bound -> all GPU same frame rate, this is only true if CPU bound is smaller than the slowest GPU speed.

On the radeon/nvidia side, nouveau people are in the lucky position of having not freeze their API which means they can change the way the communicate with the kernel. It's not the case for radeon and if i was to write it again today i would do it completely differently. Doesn't means this is the only explanation, just an explanation on why nouveau is capable of doing major kernel change that give major improvement.

[grotgrot]

Low End GPU

Today I learned that my 8800GT is considered a low end GPU.

The GPU can get very hot but the only game that does so is OilRush. I know this due to a very noisy fan.

[iznogood]

Don't forget the nouveau rendering lacks anisotropic and anti aliasing. Unfortunately PTS uses the high quality nexuiz preset which is not fully supported by open drivers, so comparisons are useless.

Is this true ? If yes then the test is useless.

Michael did you run the test with comparable settings ? Can you repeat it after disabling all not supported features ?