EDIT: This affects ALL G Series owners that have a sandybridge cpu(G73SW/G74SX/G53SW/G53SX), there is NO exceptions until Asus releases an update, not all games will cause cpu throttling, but so far I am comfirming more and more games that induce it.
EDIT 2: There is also a more permanent fix now as well, but its Unofficial and requires you to flash your bios. CLICK HERE to find out more,
I initially noticed this when I first got my G73SW-XA1 back in mid march, 2011. but didn't think anything of it until a poster had brought this up as some HP owners noticed that their Envy 17 SB is doing this to them. Edit:Which HP fixed their throttling problem on May 29th, 2011.
Problem is when running Prime95 the CPU stays turbo boosted at 2.3 to 2.6ghz. However, once Furmark is started at the same time, the CPU drops instantly to 798mhz. This now also can be noticed in GTA4,SC2,L4D2,WoW and anything that will put high loads on CPU + GPU at the same time. It does NOT just happen during synthetic test.
So how to fix it? Well so far it seems running ThrottleStop in monitor only mode stops any, and all throttling. You do not have to mess with any settings, simply extract and run the exe for it to work. If you would like to have it run on bootup, simply create a shortcut, and drop it into your start-up folder. To have it auto-close, go into the ThrottleStop.ini and change "DCExitTime=0" to any number you like(basically just means number of seconds before it closes, I have mine set to 5.)
There is no known downsides to using throttlestop, your CPU will still down-clock properly when not in use, and it does not run hotter, nor have I found any conflicts with battery draining faster.
Also, you do NOT have to worry about any overheating, even with throttling disabled I see no higher than a peak 81c on my CPU/GPU in a ambient room temp of 84-86f. So you really don't need to worry about that. However, the PSU does get hotter when throttling is disabled when there is significant load on CPU + GPU. So just watch for that, though it should be ok for the most part.
More Permanent Fix This fix is 100% unofficial, and will require you to flash the BIOS. Which can be done with EasyFlash from within the BIOS menu.This is still done at your OWN RISK, so I am NOT responsible for any laptops not working after flashing.(However as a side note, flashing the bios is a fairly safe thing to do, especially when using the built in flasher Asus already provides.) *Warning, this also might put more strain on your battery when running on battery only, But I've yet so see any difference during my test. Just beware of the possibility, I am in no way responsible for any damages done.
What this fix does is disable Bi Directional PROCHOT within the bios, so there will be no need to run Throttlestop on bootup anymore. I've been using this bios for quite some time, and I have had no problems, so the risk should be minimal. Also, as a bonus, this bios also enables AES(Learn More) that Asus so kindly forgot to implement into our original bios. The download link is below and the instructions for flashing will be below that.
Step 1: Download the file above, extract the 2 files onto a flash drive. Leave the flash drive plugged in.
Step 2: Reboot the computer, and press and hold F2 to get into the bios. Go to Advanced tab, then Start EASY FLASH.
Step 3: You should see the 2 extracted files once into easy flash. Using arrow keys, choose the one with _TFIX(_ORIG is for if you want to go back to default bios). Then hit enter and Yes to update. Let it do its thing, (it will shutdown, but just turn it back on after it shuts down).
Step 4: Once your back into windows, to test for success, download this MSR Tool and type in 0x1fc in the MSR Number box, then click Read MSR. Under the EAX box, you should see "0x0004005E", E being the key here that BD-PROCHOT is disabled(it will be F, it PROHOT is still enabled).
Step 5(optional): You can also test by running Prime95 + Furmark at the same time. Using RealTemp 3.67 to monitor cpu clocks. It should never fall below 1995mhz essentially, but for me, lowest I see it go is 22xxmhz.
Furmark 1.9.0(puts the graphic card at 99-100% load, again, just another good program to check for stability, of course, also just the programs I used to show consistent throttling.) http://majorgeeks.com/FurMark_d4183.html
Also, if anyone gets some very interesting results, feel free to post in this thread, hopefully this will all lead to an official fix from Asus. We may have a temp fix for now, but always nice to hear official word and for an official update solving this problem. Thanks for reading!
Came across this post and wanted to share that ThrottleStop is up to version 8 now, and you can create a run task to get this to work at startup with elevated permissions to get through UAC. Some neat features on there, going to stress test it with Diablo 3 and League of Legends and will report back on how the G73SW (Bios 205) performed.
Saw some posts about possibly needing a better power supply, anyone know any additional information on that or was that for other specific laptops that needed this fix as well?