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What should be the TJ max for 45nm Wolfdale CPU?

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a b à CPUs
July 19, 2009 6:52:15 AM

I use Realtemp for temp monitoring.
What should be the TJ max for an C2D E7300?
Its 45nm wolfdale .
I was confused when i searched abt this on google.There were mixed answers .Some saying it should be 100 and some saying 95.
Pls help me.

More about : max 45nm wolfdale cpu

July 19, 2009 11:16:45 AM

http://www.tomshardware.co.uk/intel-dts-specs,news-2946...

This is a little old, so doesn't actually cover your *exact* CPU. However, it does seem that there is no certainty due to Intel's reticence to confirm such things. It does mention the 7100 series though, and gives a tjmax of 100, so I would be more inclined to believe that.
a b à CPUs
July 19, 2009 11:46:20 AM

Does that mean TJ max for my cpu is 100c?
I have seen some forums where ppl say that it is 90-95.
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July 19, 2009 12:07:27 PM

I've actually just realised I made a mistake in my original reply. I apologise for that. That list has the E7000 series, and I think that was released late enough to include the E7300. As that's the official list from Intel, I would set the TJ max at 100.
a b à CPUs
July 19, 2009 12:21:15 PM

Tjunction Max is not a constant. It will differ between CPUs and even between cores. Unless you want to properly calibrate Real Temp or Speedfan just use the defaults, chances are you are only a few degrees out at load (but could be way off at idle). Also, read the temperature guide in the Overclocking section.

Oh and ignore the values in that article, Intel changed their mind on some after a bit of persuasion from certain individuals stating that they don't make any sense.
July 19, 2009 12:26:32 PM

Did they really? Interesting. So it's basically pick your number?
a b à CPUs
July 19, 2009 12:30:29 PM

It's possible to make an educated guess but it's not worth the effort. Real Temp defaults are based on quite thorough testing as is, while Core Temp uses Intel's Tjunction Targets I believe. It's only really worth changing if your load temps are significantly different between the cores at full load, NOT at idle.
a b à CPUs
July 19, 2009 5:36:57 PM

So i guess i should keep it at 100.
a b à CPUs
July 20, 2009 5:17:48 AM

These are my idle temps with different Temp monitoring softwares:

Real temp: (core 1 and 2): 45c (TJ max 100)

Real temp:39c (TJ max 95)

CPUID HW : 44c

Everest ultimate :45c

Speedfan: 50c.

So which one should i believe.
a b à CPUs
July 20, 2009 7:08:12 AM

The only difference between all of them is Tj Max. At idle you shouldn't believe any of them. Idle temps generally aren't trustworthy without calibration due to slope error (sensors become less and less accurate as the chip cools). Only load really matters. If you want to calibrate your load and idle temps using some form of scientific method as opposed to blindly guessing a single variable you should read this: http://www.tomshardware.com/forum/221745-29-sticky-core...
a b à CPUs
July 20, 2009 3:13:28 PM

Coretemp says 100 is my tj max.
But can you pls tell me why ppl on other threads and forums say that the TJ max is 95 for these 45nm wolfdales?
a b à CPUs
July 20, 2009 5:48:55 PM

Its very hot in summer in India.
The temps these days are around 40c(noon).
So i think my temps are fine.

And i would like to ask one more thing.
My CPU fan speed is around 1500rpm.
I can max it to 3500RPM.
But it does not give me ANY temps change. Why so?

BTW I am using stock HSF from intel.
a b à CPUs
July 21, 2009 1:13:20 AM

Quote:
CoreTemp will tell you your cpu's tjMax.

It will tell you what Arthur Liberman thinks your Tj Max is actually.

shubham1401 said:
Coretemp says 100 is my tj max.
But can you pls tell me why ppl on other threads and forums say that the TJ max is 95 for these 45nm wolfdales?

Because nobody really knows what your CPU is.

Quote:
Probably just playing it safe. Kinda like you tell people the speed limit is 45, there gonna drive 50.
Mine is 85c. The moderator at CoreTemp told me always keep your cpu temps at least 15c lower than tjmax temps to be safe. So for me that would be a 70c cpu temp max. I play it safe and even in summer my temps never go above 65c at 100% load. During gaming they never go above 62c.
Coretemps readings (core #0, Core#1) are the actual cpu temps, not the tj temps.


Ok let's get this straight. It doesn't matter what you put Tj Max at because it doesn't make your CPU run differently. If you put Tj Max at 100C and are currently reporting a temp of 50C then your Distance to Tj Max is 50 and will remain at 50 assuming that load and ambient temperature do not change. If you put Tj Max at 250C then your temp will be reported as 200C but it doesn't matter because the distance to Tj Max is still 50, which means you're safe. If you set Tj Max to 50C then you'll report 0C temps but clearly you aren't running at that. The CPU will begin throttling when it reaches ~DTS=2, not when it reaches 48C, 98C, 198C or whatever you want your temperature program to show. The actual temperature does not affect throttling, only what the DTS is reporting.

The reported temperature really doesn't matter and without proper calibration it is essentially just guesswork deciding on Tj Max. The introduction of Core i7 greatly improved sensor accuracy and Tjunction Target is stored in a Model-Specific Register that is software-readable, so guesswork isn't really needed for it. 45nm Core 2 is the worst for sensor accuracy.
a b à CPUs
July 21, 2009 12:18:56 PM

Not in Real Temp or Speedfan, you can change it from the defaults.
a b à CPUs
July 21, 2009 2:52:57 PM

Well I'm a lil confused now.
There are two different things.
One is TJ max and other is Thermal specification by intel (74.1c for my CPU).


By what i have understood with the help of you guys is that we have to maintain the distance from the TJ max (pls correct me if i m wrong).

But what abt that 74.1c stated by INTEL?
a b à CPUs
July 21, 2009 3:12:51 PM

What distance from the TJ max is safe for the CPU.
I want 3 years more life from my CPU.
a b à CPUs
July 22, 2009 12:56:11 AM

shubham1401 said:
But what abt that 74.1c stated by INTEL?

Thermal Specification (except for mobile CPUs) refers to TCase Max. The most practical definition for TCase is the "CPU temp" that you will find in SpeedFan and HWMonitor, which is usually lower than the core temps, as it should be. This reading is taken from a sensor between and below the cores, not the cores themselves. TCase Max or Thermal Spec is the maximum temperature that this sensor should reach, but when overclocking without adequate cooling it's quite possible to go higher.

Technically this isn't a 100% accurate definition, but the "real" TCase can't be measured without drilling a hole in your heatspreader and inserting a thermocouple, which isn't that practical ;) 

shubham1401 said:
What distance from the TJ max is safe for the CPU.
I want 3 years more life from my CPU.


A distance of 20 should be fine, but try to keep it greater than 25 if you can. This means <75C or <70C depending on which Tj Max your program is using (100C or 95C).
a b à CPUs
July 22, 2009 2:57:22 PM

Thank You very much Randomizer.
Dude you helped a lot!
a b à CPUs
July 23, 2009 2:02:29 AM

No problem :) 
!