***edit for atitool fix***
Using 158.36 drivers as most of the 16x.xx don't allow overclocking.
The M1330 unoverclocked can run upwards of 104 degrees C indicated in the Dell temp censors. Many of us think this is just a misread, but the system acknowledges it anyhow. The problem is that the temp will peak to this on certain scenes and when it does, the 8400m GS card will downclock to low power 3d, resulting in these fps drops at, say, transporter globes on UT. This is also the same reason why people see much lower scores in 3dmark with it constantly reaching max on the 2nd bench of 05. You can monitor this using rivatuner's monitor.
I fixed this by using ATITool, not ATI Tray Tools and not Rivatuner, to set the low power 3d AND 2d clock settings to the same settings as the high power. Rivatuner won't allow you to set the 2d to the 3d settings, even when telling it to keep all settings the same. Another option would be to use rivatuner and set the 2d to max memory it will allow you and you'll keep the downclocking protection as well as not see as much of a drop in fps. Keep in mind that dropping performance on this about 5% will drastically reduce the temp fast.
At 104 the card downclocks to low power 3d, at 105, the card downclocks to 2d. That's why you have to set 2d. Also, people have mentioned that the actual temp is 10-20 degrees lower than indicated AND the card is rated up to 150 degrees due to newer design over the 7xxx series and so on.
I hope this helps.
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ATITool would not run correctly in Vista 64 but I have finally fixed it:
FIXED, I figured out what to change to get ATITool 100% functional in Vista 64.
1) We know about the certification thing, I'm doing my method of test certifying and then removing the test watermarks. That problem solved, though ATITool is to have it's own cert in the next release, thank you =)
My driver cert method:
http://www.nvnews.net/vbulletin/showthread.php?t=96785
2) I have been having to disable and re-enable the atitool driver in the device manager about 10-20 times, resulting in some crashes. I fixed this finally by going into regedit and changing this key:
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Servic es\ATITool]
"Start"=dword:00000003
I changed to
"Start"=dword:00000000
I've tried this multiple times, if start is 1,2,3, or 4, ATITool will "kernel mode driver does not seem to be running" about 95% of the time; at 0 it will load 100% of the time!!!
Congrats! With this fix this is now 100% vista 64 capable! It also beats out rivatuner because you don't have 2d limits. Since my card thinks it runs at 105 degrees constantly, it always downclocks, but problem solved.
M1330 game fps slowdown fix
I think you already have a thread where you are talking mostly to urself 
