SGX comments (pruned from Amd z430 thread)

Some of the US Galaxy S phones are now showing up on GLBenchmark, and T-Mobile did another good job of not messing up the driver/software environment of the Vibrant, keeping it closest to the reference Galaxy S.

The original Galaxy S and some other phones were also retested, and the benchmark now much more accurately guages the performance advantage of the SGX540.

 

And finally, a 2.0 OpenGL ES test of the new generation of phones:

http://www.youtube.com/watch?v=cl4p5JI0-gQ&sns=em



http://androidandme.com/2010/07/news/galaxy-s-lineup-leads-the-pack-in-android-gpu-benchmarks/

 

Correct me if I'm wrong.

It seems that the execution units of the handheld GPUs are very small and must do any instruction in more cycles than a desktop GPU and this is because instead of having units of several FP32 in parallel for the same task or a SIMD configuration they have only one FP32 unit, making the need of more cycles for rendering an entire frame.

 

It entirely depends on the device.

 

As simon has already pointed out, there is a quite a bit of variation in design of embedded GPUs.

 

Hmmm does anyone know how many AA samples GLBenchmark is using for the FSAA tests? The performance difference between noAA and AA looks fairly reasonable on all tested devices. Could it be it's only 2x samples?

 

It's 4 samples.

 

Interesting. If it's not a multi-sample implementation it could be an indication that pixel fill-rate isn't the primary limitation. Guess it makes sense for an 850x480 display.

 

The devices in the comparison all use multisampling.

 

What is the difference between the GLBenchmark HD and Pro results? Is one native resolution dependent while the other device resolution independent? I'm just curious why the iPhone 4 (SGX535) can be comparable to the Galaxy S/Vibrant (SGX540) in the HD benchmark but be 33% slower in CPU skinning and 50% slower in the Pro benchmark for GPU skinning.

The low-level tests also have the iPhone 4 and Galaxy S/Vibrant being very close for most tests except fill-rate and some of the lighting tests. Should the SGX540 be consistently faster than the SGX535 or maybe this is the result of the iPhone 4's GPU being clocked higher or driver stack being more mature?

 

They're completely different benchmark scenes. See the screenshots at the bottom of this page:
http://www.glbenchmark.com/tools.jsp?benchmark=glpro11

The HD tests are entirely vsync limited on the iPhone and Galaxy S. The tests run for 30s, so divide the number of frames rendered by this and you get 59.9 fps on the iPhone and 55.8 fps on the Galaxy S, which in both cases corresponds to the screen refresh rate.

 

Thanks for clarifying the benchmark issues.