Stop m15x GPU downclocking

Stop m15x GPU downclocking, and stop the maddness! (XP)

By default, you cannot disable Nvidia PowerMizer on the Alienware m15x’s 8800m GTX GPU. When setting PowerMizer Off, the GPU is downclocked 383/300 core/memory, ½ the systems power…

PowerMizer Off (may as well remove “Mizer” because this is “Power Off”!)


So you’re dependant on Nvidia PowerMizer settings which dynamically adjusts GPU speeds all the way from 200/100 to 500/800 (max). It’s a great feature, but not perfect. I need a way to control my GPU to run full speed.

Using the stock Nvidia Drivers (165.32) I was able to fix this.

Open the registry editor, Start -> Run regedit, and navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Video.

Right click the Video folder and Find PerfLevelSrc. It will be in one of these



Double click PerfLevelSrc and change the value from 3333 to 2222.




This will force PowerMizer to run the GPU full speed (500/800).
Reboot and you’re set.

With PowerMizer enabled the GPU will run full speed no matter what.



The GPU still downclocks (383/300) with PowerMizer off, so leave it on.

Note: Changing this registry key alters the way the system was designed to run. Use at your own risk!

You'll want to load ntune works great with AW drivers and it is Nvidia supported

I've run the stability test for 20 min and a few 3dmark06's and temps have not breached 70C so all is looking really good. I haven’t had a chance to put a good 4+ hours gaming on it yet, but with these temps i predict no problems.

no, the exact opposite. this fixes the downclocking when plugged in. Unfortunately i cannot find anything to remedy the downclocking on battery... this appears to be hardware based so i don’t think we're fixing that with anything less then a custom BIOS flash..

Not 100% sure on vista but that reg key should exist so it should work.

As far as overheating goes. Here’s the deal, with the latest BIOS the system forces you to use PowerMizer. This should not be a problem when playing games like Crysis and BioShock as they are so GPU intensive all the time, powermizer will just have the GPU run full force.

The problem with Powermizer can be with some other games. At times some parts of games are not so GPU intensive. For example, when staring at a wall it does not take much to render those textures, so Powermizer will temporarily downclock the GPU to conserve power and stress on the GPU. Problem is with most games in < 1 second you can swing around and need your GPU back at full force. Powermizer does a good job at this but it takes about a second to re-clock the GPU. This can cause you to skip a few frames, and you normally hear an interruption in the games music.

This has happened enough for me where I need to option to have the GPU run full force no matter what PowerMizer “thinks” is good.

Furthermore if you play any games in windowed mode, like WoW, you’ll notice a drastic drop in performance. For w/e reason powermizer does not like to bump up the GPU to max unless the application is in full screen mode. This is another example when this fix is very useful.

As for overheating your system, I really don’t know. Reason why is I cannot get the system to heat up much past 70C, no matter what I throw at it. This GPU will be fine all the way up to 120C, but that should be your max.

On a side note, having the GPU run full force all the time gets the system noticeably hot to the touch. This is a bit unnecessary when surfing notebookforums.com etc. I either turn it off when not gaming, or preferably swap to the Intel GPU.

Again, use at your own risk. You can load ntune, launch NVmonitor, and have it send an on screen message alert when your GPU temps reach a specific degree. I’d set it to 90-95C just because you’ll probably want to know if your temps reach that, but its still designed to go up to 120C.

Thanks James! Always appreciate the support.

I understand that the x32 BIOS “official statement” is it fixes the downclocking, but this guide is actually based on that BIOS…

The BIOS fix does fix the GPU from downclocking when extream temps are reached.

But it removed your option to disable powermizer. Powermizer by design is a downclocking tool… while it scales by demand most of the time, its anything but perfect… when it does not function properly you will notice a sudden drop in framerate, the sound will be distorted, and this continues until it scales properly. Depending on what your doing (like gaming) this can cause some apps to be un-useable

With the X32 BIOS update, if you disable powermizer it sets the GPU to performance level 2 (balanced) which drops the GPU clocks to 383/300 (and it will not scale). so the only way (by default) to get the full 500/800 is with powermizer enabled AND a load the powermizer recognizes are performance level 1 (max).

Modifying the registry this way just forces powermizer to always set performance level 1(max).

You can query this yourself using the PowerMizer API, you’ll want to

BOOL nvGetPwrMzrLevel(OUT DWORD* pdwBatteryLevel,OUT DWORD* pdwACLevel);

You’ll also see that if you remove AC power, it will return 2 (balanced), no matter what type of load you have.
I cannot fix that, can you help? You’ll probably need to send API

BOOL nvGetPwrMzrLevel(OUT DWORD* pdwBatteryLevel 1

But why do I think it will return error for hardware escape….

Thanks again!

I wanted to add some other finding on this.
XP USERS BEWARE OF 175.80 BETA DRIVER from support.alienware.com.

On that driver I found the following behavior.
PowerMizer ON: Downclocks 275/300 (static) and does not adjust, no matter what you throw at it.
PowerMizer OFF: same as powermizer on…

You can test yourself with ntune, just launch NVMonitor and you’ll see the core/member clock speeds. Your max (8800m GTX) is 500/800. with these drivers you’re never getting higher then 275/300 with or w/o the registry hack

At this time the only fully working driver for XP is the 165.32.

I dont know about Vista, it might be the same thing...