Win 7 - Hidden properties of power management and weird performance

2

I just bought a new Alienware laptop. Benchmarks (like 3DMark 11) were great and consistent with reviews for the machine.

But I had to reinstall the OS (Win 7 Pro x64), and, in doing so, I experienced a noticeable slowdown in the benchmarks. Now, I did the song and dance of drivers, etc. - using the drivers included from Dell on the enclosed DVD, using the drivers from the Dell website themselves, using drivers from the 3rd party manufacturers. Nothing helped- benchmarks were consistently a slower by the same amount than when I got it clean from the factory.

After trying and trying and trying, I found that one program from Alienware - the control center - did seem to make a difference when I installed it. It didn't get me the full amount back, but it did move the needle.

Control center basically includes several programs in it. The main one that's relevant here is the one that manages power profiles. I quickly realized it's just a wrapper around Windows's own power management options.

Anyway, I dug and dug and dug deeper and deeper into power management. Oddly, on balanced mode, I'd get a score of say 6200. But then, on high performance mode, the score would drop to 6100 (this was consistent, after many trials back and forth). So I painstakingly went through every power option to find what the culprit was. Turns out it was Minimum Processor State. Changing that one variable in balanced mode changed the benchmark.

To test this out, I then switched to high performance mode and literally changed every variable to the same value as in balanced, including Min Proc State. And yet, still stuck at 6100.

This was when it dawned on me that the visual GUI wrapper for power management was not exposing all the settings, despite me clicking on every "Advanced" button on there.

Enter powercfg.exe. This was the tool that finally exposed for me all the settings (using -qh). So now I have a bunch of processor power management variables I have to play with that are different between balanced and high performance.

But before I get into that, I thought I would post on here and see if someone really knows power management, knows why high performance would under perform balanced mode, and, hopefully, how I can get back to the original, original performance I used to get before reformatting.

Basically, given the whole mix of variables (drivers, OS updates, background processes, Nvidia control panel, etc.), power management seems far and away the most likely culprit, and I'm dying to hear from those who really know how to manage it, and for whom this might ring familiar.

Thanks!

Bob Jones

Posted 2012-10-03T07:32:21.987

Reputation: 51

How much of a difference are we talking here? Are you sure that the laptop is not overheating and therefore throttling the CPU and/or GPU? It could be that in high performance mode it is overheating more quickly. I suggest you run a temperature monitoring program in the background when running the benchmarks. Also, it would be useful to have more information about the laptop, e.g. the exact CPU. – James P – 2012-10-03T08:25:06.913

Also, are you absolutely sure that you have installed all the drivers? If the CPU is an i7/i5 can you confirm if the Turbo Boost feature is working? – James P – 2012-10-03T08:31:00.557

The difference is fairly minor (before it was about 6350, now on balanced it's 6250, and then on high performance, 6150). The difference is small, but it's consistent and the tinkerer in me wants to figure out why.

Re: overheating, I can check the temperatures shortly.

Re: the specs, it's an i7 3620, 32 GB of RAM, Nvidia GTX 680M.

Re: drivers, yes. I've installed all the Dell ones, from the included DVD and Dell's website to be sure.

Re: TurboBoost, how would I check? Do I want that on? I assume so (?) – Bob Jones – 2012-10-04T17:00:01.733

Turbo boost safely "overclocks" your CPU when it's safely possible in order to increase performance in certain situations. TMonitor (http://www.cpuid.com/softwares/tmonitor.html) can monitor the frequency of the CPU over time and indicate when Turbo Boost is used. There is also an official Intel program (http://downloadcenter.intel.com/Detail_Desc.aspx?DwnldID=19105) although I'm not sure if it is as useful.

– James P – 2012-10-05T08:34:54.707

The difference in the benchmarks is so small though that tracking down the reason could be very difficult. If one or more of the drivers are different versions to ones you had originally it could easily explain it. It could also be down to slight differences in your 3D performance settings in the nVidia control panel. – James P – 2012-10-05T08:36:54.533

Did you have any luck checking temperatures and turbo boost status Bob? – James P – 2012-10-08T12:24:52.193

Answers

3

Well, the phenomenal guys at Dell support got this solved for me! It had to do with the explicit order in which the drivers are installed. To potentially save someone else the same headache, I'm posting it here (for my config):

  • Dell Intel HM77 Panther Point Chipset
  • Dell Intel Management Engine Interface
  • USB 3.0
  • Media Card Reader
  • Intel Ivy Bridge HD Graphics
  • Video Card Drivers
  • Intel Wireless Display 3.0 (Optional) More Information
  • Dell Atheros AR8151
  • Dell Intel Centrino Wireless-N
  • Dell Intel Centrino Wireless-N 2230 Bluetooth
  • Sound Blaster Recon3Di
  • ST Microelectronics DE351DL Free Fall Sensor
  • Synaptics Touchpad
  • Command Center
  • On Screen Display Application

Good luck all!

Bob Jones

Posted 2012-10-03T07:32:21.987

Reputation: 51