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

[Louise]

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.

Yes, but that does tell anything about the uncertainty of each measurement.

Your measurement equipment can't measure each value exactly. That is way some measurement are more expensive than others. You pay for the accuracy.

So if you measure 17345 m Watt, but the accuracy is 1000 m Watt, you can't tell anything from the just released test, as you conclude that the open source drivers are better because of the difference you are talking about is less than the accuracy.

With other words, you are only seeing noise.

That is why each measurement point needs to have an error bar, so you can tell how likely it is that the differences you see is in fact differences and not noise that comes from the measurement it self.

[Melcar]

Well, radeon on my laptop (200M) reduces battery life nearly by 1/3 (45min to 30min). If I load up DynamicClocks I gain around 10min.

[BlackStar]

45 minutes w/ fglrx vs 40 minutes w/ radeon + DynamicClocks. Not too shabby!

How old is your battery?

[SyXbiT]

don't you get tired of saying things like
"The open-source ATI stack will most certainly improve when...."



seriously. stop promising stuff. people then get mad when it doesn't happen

[GreatWalrus]

don't you get tired of saying things like
"The open-source ATI stack will most certainly improve when...."



seriously. stop promising stuff. people then get mad when it doesn't happen

Geez, Debbie Downer.

It WILL most certainly improve.

[Melcar]

45 minutes w/ fglrx vs 40 minutes w/ radeon + DynamicClocks. Not too shabby!

How old is your battery?

3 years or so. The thing is DynamicClocks really slows things down. KDE4 (no effects) is almost unbearable to use.

[GreatWalrus]

3 years or so. The thing is DynamicClocks really slows things down. KDE4 (no effects) is almost unbearable to use.

You have a nice looking desktop system though (in your sig)

[elsie]

I thought powerplay wasn't working for r500 cards in catalyst 9.2?

I have a mobility x1600 & still use fglrx 8.5(fastest & most stable for me) & I underclock the gpu to the lowest setting (135mhz) for battery & AC. Doing this keeps my laptop cool & extremely quiet!

& compiz is always on (cube & other eye candy) & doesn't suffer from the lowered clock setting.

[shamooki]

I'm stunned - you tested almost exactly my setup. Great! This article was extremely useful for me! Thanks phoronix, this reminds me why I keep reading you.

Having said that I'd really like to see the effect of powerplay on fglrx. From my own playing around with powertop and the like I could hardly see any energy savings with powerplay. Can you?

And one addition on the results: The 1400x1050 display is an IPS one (at least mine is). These panels eat really a lot of power. Lowering screen brightness is by for the most efficient energy saver on my laptop.

[shamooki]

That is why each measurement point needs to have an error bar, so you can tell how likely it is that the differences you see is in fact differences and not noise that comes from the measurement it self.

You sound like you just took a statistics class Through my work I often witness how people who are trained in statistics accusing those who acquire data to misuse statistics. While it's good to point out weak points in an analysis, I strongly believe criticism should be constructive.

To be precise: How would you quantify the uncertainty of the measurements?