Power Management: ATI Catalyst vs. Open-Source ATI Driver

[phoronix]

Phoronix: Power Management: ATI Catalyst vs. Open-Source ATI Driver

Yesterday we broke the news that AMD will stop supporting the R300-500 GPUs in the Catalyst driver. There have been well over one hundred posts in the Phoronix Forums from ATI customers upset with this decision, but fortunately, there is first-rate open-source support available. AMD continues to release documentation and code while the X.Org development community has been hard at work on the xf86-video-ati and xf86-video-radeonhd drivers along with Mesa and Gallium3D components. The main problem though is the open-source stack -- at this time -- providing poor gaming performance, but power management can also be a problem. In yesterday's article we provided some R500 comparative 2D and OpenGL benchmarks, but in this article are some power management results comparing the Catalyst 9.2 driver to the xf86-video-ati driver.

http://www.phoronix.com/vr.php?view=13566

[questioneer]

on page 2 you write that you are using catalyst 9.3

typo?

[Michael]

on page 2 you write that you are using catalyst 9.3

typo?

Yes, fixed. Thanks.

[BlackStar]

Interesting. This seems to mirror my experience on a desktop R500 part (X1950Pro), where radeon consumes marginally less power than fglrx on idle (about 0.5-1W).

The situation is reversed with my R700 (4850HD), however: radeonhd consumes a whopping 35W more than fglrx! That will be more difficult to fix, but hopefully not impossible.

In any case, the radeon/radeonhd devs are doing a great job!

[sreyan]

Michael,
It would be nice to see performance/power consumption. I know that is not easy or trivial to measure. Many folks might say that the open source drivers use less power because they don't do anything.

[Pfanne]

there is a small mistake the on second page

The difference between the two averages though is just 155 Milliwatts. The power consumption peaked at 24522 Watts, which is over 600 Milliwatts less than its open-source alternative. The power consumption bottomed out at 20112 Milliwatts, which is also less.

i hope this is supposed to milliwatts otherwise this card wouldnt be fit for a notebook
btw thanks for this great article

[NeoBrain]

Interesting. This seems to mirror my experience on a desktop R500 part (X1950Pro), where radeon consumes marginally less power than fglrx on idle (about 0.5-1W).

The situation is reversed with my R700 (4850HD), however: radeonhd consumes a whopping 35W more than fglrx! That will be more difficult to fix, but hopefully not impossible.

I don't think any power management code in radeon/hd is written for anything higher than R5xx, so that's quite normal I guess

[Zhick]

Was DynamicClocks enabled in xorg.conf? You say both drivers were left at their defaults, so probably not. Would be nice to see what impact (if any) it has.
Also since this is a notebook were power-consumption is critical, and performance usualy secondary, I think you should also test with lower power-states, as I think that's a more realistic useage-scenario.
But I do realize you did this article in a very short time, so I'm not complaining. I just make suggestions.

[Louise]

You mean to tell me, that the open source drivers, which have no power management uses less power then the closed source driver with power management?

I think this proves, that the test suite is useless without error bars.

Come on Phoronix. Statistical data without error bars are useless. They don't tell anything at all.

How will you convince that the uncertainty isn't dominant?

[Michael]

You mean to tell me, that the open source drivers, which have no power management uses less power then the closed source driver with power management?

Yes, on specifically the Mobility X1400 in our test configuration. The likely explanation is that all areas of the GPU aren't being enabled in the open-source stack at this time.

I think this proves, that the test suite is useless without error bars.

Come on Phoronix. Statistical data without error bars are useless. They don't tell anything at all.

How will you convince that the uncertainty isn't dominant?

In this article are line graphs that show all plotted points.... Along with the minimum, average, and maximums mentioned. This is all of the recorded data for the power consumption.