Dell XPS M1330 - CPU Overheating ... Wrong VID ?! Need help to fix it !

Hi, guys !

I've just bought a Dell XPS M1330, which had Windows Vista. I've erased the Vista, installed the XP and updated the BIOS to the lattest version. As I was experiencing random freezings, I ran Orthos ... the CPU temperature rose rapidly to ~80C and in less than 3 minutes was above 90C. After ~5 minutes, it has reached the critical value and the laptop shutted down, even though the fan was spinning above 5000 rpm.

Using CoreTemp and CPU-Z, I've seen that the VID of the CPU (T7500) is ~1.2500V, but CPU-Z shows 1.36V and even 1.40V sometimes. Using the RMClock I've found the CPU to be stable @ 2200MHz @ 1.20V (maybe even less).

Is there a way (BIOS Modd or something) to solve this ? Any idea why the laptop is overvolting the CPU ? I've changed the OS 5-6 times in the last two days (4*Windows XP + Vista Ultimate x64 + Windows 7 Beta) but ... same story.

 

Try the undervolting guide. I had good success on both my M1330 and Vostro 1720.

http://forum.notebookreview.com/showthread.php?t=235824

 

The undervolting using RMClock isn't a good solution from my point of view. A good BIOS would be much better.

After testing for a couple of minutes 2 other Dell laptops (both of them being Inspiron 1525 using T5870 and T7250 CPU's) the overvolting (~0.1V above VID as detected by CoreTemp) seems to be a problem of Dell laptops.

 

CPU-Z has trouble with VID's. I don't think it's ever read my T9500's voltage correctly. RMClock has never given me trouble.

I currently have my 8x multiplier (2.6GHz) at 1.000v.

 

That's correct!. The current version of cpu-z 1.51 doesn't translate VID tables correct. It uses tables which are only valid for desktops and differ for notebooks. I e-mailed this issue some time ago to the cpu-z support and got a response that they are aware of this issue and it will be fixed in the next version.

Until then use RMClock to read the correct VID Voltages. These values are correct and differ from what cpu-z reports. Actually you have to make sure "Advanced CPU settings" / CPU type selection
[x] Mobile
is set. Otherwise you get the same wrong cpu-z values.

You probably know that the VID isn't the actual voltage the VRMs supply, but the wish of the CPU of a particular voltage level. This get's adjusted with some unknown bias values of the BIOS for the XPS M1330 and further modified by VRM tolerances such that the real voltage might differ slightly. However for comparison purpose with other XPS M1330 these values are fine - everybody uses then.

The T7500 is a particular hot CPU. Depeding on the individual CPU you have (they all differ slightly in thermal dissipation), those T7500 might run into thermal throtteling (typically around °95C with this CPU) at stock voltage. I do know that some - if not most - M1330 that Dell shipped easily hit thermal throtteling with tools such as Orthos.

Thermal Throtteling 2 (TM2) that get's triggered at ~95°C with the current Dell BIOS for the XPS M1330 looks like this:



If other components such as the chipset get very hot as well (and they often do since the CPU heatpipe connects them as well and if the CPU gets hot, then the chipset does as well) the Dell BIOS does trigger Thermal Throtteling 1 (TM1). This is triggered at lower temps and looks like this:



The difference between the purple and red bar is the actual throttle in TM1, while VID/FID changes are thos of TM2.

If your CPU hits it's thermal limit even with undervolting applied, you might want to contact Dell for support. Reseating the CPU cooling assembly or replacing this one might help.