Processor stuck at 800mhz supposed to be 2000mhz, mother board or cpu?

[AnMig]

Dell™ Inspiron™ XPS Gen 2
Intel pentium M 760 (core speed 2ghz, 533mhz fsb) socket 479
this lap top: http://www.pcmag.com/article2/0,2817,1769520,00.asp

Update:
not CPU
not AC adapter
not Bios

solution thanks to Hacp RMclock (software overclock)


I have this Lap Top that appears to be stuck at 800mhz both Linux Mint 10 and Windows 7.
CPU-Z correctly identifies the CPU as Pentium M 760 but the the core speed is stuck at 800mhz (Bus 133mxz multiplier x6)

Speed step is enabled in the bios (if disabled it will default to lowest speed 800mhz)

Also once in a while even before reaching the boot loader the CPU fan will spin at its max and when it does this the CPU boots at 200mhz (Bus 36mhz multiplier x6). Things are crawling but it appears to work. Reboot will usually bring it back to 800mhz.

Running Prime 95 or stressing the lap top (watching HD movie) will not bring the CPU to 2ghz (speed step is supposed to do this)

Bios correctly identifies the CPU as:
Pentium M
Current clock speed = 2.00ghz after about 30secs in the bios it goes down to 800mhz
Minimum Clock speed = 800mhz
Maximum Clock Speed = 2.00ghz

Things that I have done:
I have updated the bios to the latest version A05
I reseated the CPU and placed new thermal paste

I am now at a crossroad since I don't know if its motherboard problem or a CPU problem.
Before I buy a used CPU, I just wanted to get someones opinion. If its a mother board problem then I wont bother getting a another cpu.

It appears to be speed step problem but unfortunately disabling it in the bios defaults to 800mhz.

I am hoping this has also happened to someone and learn from their experience.

Question:
Mother board or CPU problem

P.S. dissembling the laptop was not that hard (had the service manual) it wasn't really that complicated.

 

[CurseTheSky]

Dumb question - have you tried this both with the AC adapter connected, and on battery? Also, is this the original AC adapter or an aftermarket?

The reason I ask is my laptop, though a different brand and a bit newer, seems to automatically throttle the CPU if there isn't enough power coming in. If you run with a lower wattage AC adapter, for example, it won't allow the CPU to go 100% speed.

 

[AnMig]

Wow brilliant suggestion, this is an aftermarket power brick (cheap one off ebay) It does appear to work (charge the battery ect) but maybe that is the problem. Now I have to decide decide buy new power brick, or CPU.

I do have a tester around but it will only tell the amount of volts. It will sometimes give me a unidentified AC source during boot.

Good suggestion.

 

[AnMig]

Had the old AC brick still works but (will not boot with it connected)

with the old brick CPU boots at 600mhz
with the replacement brick 800mhz

Maybe it is the brick (its actually Dell replacement)


Crap shoot
Pentium M 760 in EBAY is around $20-30
Replacement brick (dell) $24 ebay

 

[cubby1223]

Definitely get a proper power adapter. I've seen another Dell that for some reason the business continues to use an HP brand power adapter connected to it, and the Dell runs off the AC power but refuses to recharge the battery (an alert in the Dell software says so). Dell is definitely detecting non-Dell power adapters, so who knows maybe it is self-adjusting the clock speed based on that.

 

[CurseTheSky]

I've never seen a processor go bad. So my first vote would be a problem with the AC adapter or other power management hardware (hopefully the cheap AC adapter didn't damage anything), and my second vote would be the motherboard. If it is the motherboard, you may be better off just looking for a newer, cheap laptop.

 

[AnMig]

ordered another AC adapter, if it does not work then I will have to live with a 800mhz laptop.

Thanks

 

[JWade]

there is a prgram called speedswitch that can allow you to adjust the speedstep when its stuck sometimes.

 

[ViviTheMage]

Go into BIOS and disable speedstep, I see it pretty frequently at work.

 

[Zap]

Go into BIOS and disable speedstep, I see it pretty frequently at work.

No, you want to ENABLE SpeedStep. Disabling it will keep CPU at minimum multiplier. It worked that way with two Dell notebooks I've had.

 

[ViviTheMage]

No, you want to ENABLE SpeedStep. Disabling it will keep CPU at minimum multiplier. It worked that way with two Dell notebooks I've had.

I do the opposite, DISABLE speedstep, so it doesn't turn the speed down, worked on 20 or so D620/D630's, and older T42's i've dealt with. Enabling it just causes it to go back to 768mhz, or 428mhz, or whatever it thinks, it wants to be at.

 

[VirtualLarry]

My experience with mobile chips is that speedstep needs to be enabled, otherwise it defaults to a slower speed.

 

[Zap]

My experience with mobile chips is that speedstep needs to be enabled, otherwise it defaults to a slower speed.

That's been my exact experience, with a Latitude D800 and Inspiron 6000.

 

[ViviTheMage]

OP, try the opposite of what the BIOS is in.

Works for me to turn it off in D6x0's, and T42's that have similiar issues.

 

[C1]

Some interesting reading about DELL power adapters for mobile computers:

http://www.tomshardware.com/forum/9519-2-dell-laptop-power-jack-pinout

http://www.laptop-junction.com/toast/content/inside-dell-ac-power-adapter-mystery-revealed

 

[AnMig]

Yes I tried both speed step enabled and disabled, cpu still boots at 800mhz. My bios states that if speed step is disabled it will default to the lower speed (800mhz).

With speed step enabled when I boot into the bios it will initially say CPU running at 2000mhz then after a few seconds in the bios it will go down to 800mhz (so I think the processor is able to go to 2000mhz)

With speed step disabled initial boot to bios is 800mhz right away.

I am hoping its the AC adapter as thats the only thing I can do something about. Waiting for the new one.


"there is a program called speed switch that can allow you to adjust the speed step when its stuck sometimes"

Will try to look for this program.
__________________

 

[techs]

Go into the bios and look for setting that's labeled something like "Adapter Warnings" and enable it.
If your power supply doesn't provide enough power OR if the laptop can't identify the power supply it will fix the cpu at the lowest speed. Then, at the end of the bios screen you will get the adapter warning, and that will tell you if your adapter is the problem.

 

[AnMig]

"Go into the bios and look for setting that's labeled something like "Adapter Warnings" and enable it."

It is enabled (no option to turn off) it does appear to identify my adapter as 130w.

Some interesting reading about DELL power adapters for mobile computers:

http://www.tomshardware.com/forum/95...er-jack-pinout

http://www.laptop-junction.com/toast...stery-revealed

wow did not realize dell complicated the adapter with the 3rd pin identifier. Most of the problems however with this was related to the battery not charging and giving the unidentified AC adapter error.

Also speed switch is not available in windows 7 or mint 10.

peace

 

[CurseTheSky]

Recent (~4 years or so) HP laptops also have a third "smart pin" in their adapters. Laptop AC adapters are one of those things that you really don't want to cheap out on. Don't spend $100 for a replacement at the OEM's website, but certainly look around on Amazon / Ebay / etc. for a reputable company with an original part.

 

[Zap]

An idea... if you are trying to see if the adapter is the cause... if the adapter still charges the battery, then run from battery to see if the processor can do full speed. That takes the 3rd party adapter out of the equation.

AnMig, have you monitored CPU temperatures? Maybe it is thermal throttling instead of SpeedStepping?

 

[AnMig]

"An idea... if you are trying to see if the adapter is the cause... if the adapter still charges the battery, then run from battery to see if the processor can do full speed. That takes the 3rd party adapter out of the equation.

AnMig, have you monitored CPU temperatures? Maybe it is thermal throttling instead of SpeedStepping?"

Battery is charging ok (old battery though), processor wont step up even on battery, tried maximising power settings in windows 7 both on battery and ac.

dont think its a temp problem, I did re-apply new thermal paste and re-seated the heatsink.

will try to look for temp monitoring program.

 

[techs]

On slightly older dell laptops some models needed the quickset utility installed or else the processor ran at the slowest speed.

Also, are you sure its not running at the rated speed under load?
You can use WCPUCLK to see the speed in real time.

 

[AnMig]

cant get quickset to install, tried several versions, gives me unsupported system or processor. Did I mention it also runs at 800mhz even on Linux Mint 10. (no quickset for this).

I was checking realtime CPU speed using conky in Linux and CPU-Z in Windows 7. I did install WCPUCLK and despite running prime 95 CPU speed did not budge from 800mhz (798.05)

I think its the MOBO preventing it from stepping up. Hopefully its the AC adpater (ordered a new one).

Thanks for the input.

 

[hal2kilo]

Definitely get a proper power adapter. I've seen another Dell that for some reason the business continues to use an HP brand power adapter connected to it, and the Dell runs off the AC power but refuses to recharge the battery (an alert in the Dell software says so). Dell is definitely detecting non-Dell power adapters, so who knows maybe it is self-adjusting the clock speed based on that.

Can't quite remember the exact wording, but occasionally I've gotten those Dell boot error messages that the AC adapter isn't working properly. I've wondered about whether the AC adapter is getting flakey. Next time it happens, I'll check to see if I'm runnig at the right clock. Both of my Dells are using Dell adapters. I know I have issues with my Vostro battery. I use a program called Battery Bar. I think it reports whatever intelligence they build into the batteries but I think the batteries lie. The most reliable indication is the percent of useful life which I've found to be the most definitive indication of whether the battery is going to perform well.

 

[IntelUser2000]

Wow, I've seen this exact thing happen to the same model. Same chip too. I've even took it apart. The fan was never running so I assumed that might have been the case but I couldn't verify it because I didn't have the laptop long enough and didn't have tools to test it.

-Tried switching BIOS settings
-Tried to force the speed higher
-They didn't have the original adapter either
-When I did manage to change the speed from 800MHz, it went even lower which wasn't my goal

It was pathetic because with the Geforce Go 7800 chip it couldn't even run World of Warcraft at everything set to low, still lagged getting 10-15 fps. Processor was holding it back pretty badly.