wierd CPU motherboard issue

[jeetu]

Few months back i assembled a comp with following specification. Cpu- E4600(Core 2 2.4Ghz 2mb cache) , Motherboard - Gigabyte GA-G31M-L2L motherboard, Graphic Card - XFX 8600GT , Ram - Kingston 1+1 gb , ddr2 667 value, Hard Disk - Seagate 250GB and Western Digital 250 GB and SMPS -Coolermaster 550W. I have installed few extra fans on the cabinet as well as on both hard disks. I am using Windows XP Sp3.
My m/b supports various overclocking features but so far i have not used them.
For first few months all the cpu benchmark (from Scisoft Sandra and others) were upto the mark. However yday when i did it again after about one month i noticed that the scores were at about 55% of the previos ones. From Cpuz i checked that my multiplier was locked at 6x instead of 12x and it wasn't increasing even on high load s/w lke Prime95.
To rectify that i went to bios and found out that it the multiplier was set at 6x instead of 12x , so i saved the multiplier setting at 12x and restarted the comp, i was shocked to find that the bios again changed CPU multiplier at 6x.
On Advanced Bios Features there are 3 related setting. CPU Enhanced Halt (CIE) , CPU Thermal Montitor 2(TM2) and CPU EIST Function. After much experimenatation I found out that only ny Disabling TM2 , i can lock my CPU multiplier at 12x. It is weird by itself because my cpu tempearature is between 40 to 50 Celcuis in idle load and 65 to 70 Celcuis at full load (as noted by Speedfan /Everest).
After saving this bios setting now CPUz shows 6x multiplier at low load (1200MHZ) and at 12x (2400 Mhz) at higher load. So again i checked the cpu benchmark and to my shock the benchmark score were still showing at 55% of its normal values.
Then as a last resort i turned off both CPU Enhanced Halt (CIE) and CPU EIST function too. Now CPUz shows constant 12x mutilier running at (2400 Mhz). I again tried Cpu benchmark tools and even now the scores are atill at 55% of normal values.
I even formated my hard disk and reinstalled the operating system twice but the problem is still there. I am now stuck at 1200Mhz effective speed instead of 2400 Mhz.
Clearly a hardware issue is involved here. Could anybody tell me where the actual fault is ( which product like Cpu or motherboard), so i can replace it as it is still under warranty.
I haven't seen any fault like this, Please help me resolve this issue.
Thanks in advance,
Abhijeet

 

[hellgate]

did u bench with Everest and 3DMark06?if yes then post ur original and current benches.
i wud suggest u to go to the oc sec of bios and change everything to manual from auto.
set fsb to 200MHz and multi to 6x.enable C1E and EIST.
see wat happens.

 

[pimpom]

jeetu, you gave a clear detailed account of the problem and what you did in trying to solve it. Many don't do that and we have to drag the details out of them bit by bit.

Unless I missed something in your post, you have not yet cleared the BIOS, have you? Sometimes it happens that all BIOS settings appear OK and under control, but some unknown factor still causes a problem. Even restoring default settings from the BIOS menu doesn't work, but clearing it by removing the battery and using the 'clear' jumper does work. I suggest you clear the BIOS and start again.

 

[darklord]

My initial guess would be that the CPU is throttling.This is related to the CPU overheating.
I am not sure if E4600 suffered from the famed IHS issue but since even the latest 45nm chips are not spared of it,lets just assume it suffers too.
Also if the chip that you have is a very bad bin then chances are that the VID is quite high.
VID is the minimum voltage required to run the chip at stock speed stably.
So its pretty straight forward, Lower VID = better binned chip, Higher VID = mediocre binned chip.
Now lets assume that you have a chip with bad VID then with more volts needed at stock, your chip tends to work hotter compared to ones with lower VID.
I am not sure what cooler came with the E4600 but if at all it was bundled with the crappy cooler that comes with the 45nm Dual cores these days then it is insufficient.

Current generation CPUs are designed to shut down or throttle if they exceed the normal temperature envelope.
NOw when you run and benchmark that involves the CPU and the CPU is at 100% usage then the temp shoots up and if this is too much the chip will throttle.
SO my guess is this is what is happening.
Before you turned off EIST, EIST was clocking it down to reduce temps.Now that you have it turned off, it might be overheating and throttling. Full Load temps of 65-70c are just too much.
Also how are you monitoring the temps ?
Since you havent specifically mentioned it, i am assuming you are using the BIOS to monitor it. The BIOS shows temps from the thermal diode in the socket on the motherboard and these temps are usually 10-15C lower than actual core temps.
I suggest you download a small tool called CoreTemp or RealTemp.Google for it.
Monitor the temperatures with this and these will show you core temperatures which are read from the thermal diodes inside the CPU which are much more accurate.
That should answer a lot of questions.

Hope this helps.

Cheers !
Darky

 

[jeetu]

My initial guess would be that the CPU is throttling.This is related to the CPU overheating.

Just replying this thread after a long gap , incase someone else shared the issue.
P.s. Thanks for your input Darklord.
I replaced this motherbaord with another one , only to find that this issue is replicated on another g31-s2l motherboard. My Cpu is fine , i tested it on another 2 motherboards. It gives me 12X spped with proper benchmark results.
It took me a lot of gogling to gain back my CPU speed. It works atleast in win XP (the only o.s. i tried this on).
I used 2 softwares in combo to gain back my CPU speed. "RmClock" & "Crystal-cpuid". I removed the thermal throttle through RmClock. I created 2 shortcuts with votage & CPU speed. Now i can manually switch from 1200 to 2400 at the click of qa mouse.

Hope this helps to another other guy facing same issue with this motherboad.