E6400 Tempertature Offsets

[2tonedug]

Hi everyone. I've been lurking for a couple of weeks now and decided to join the forum.

I've read both the overclockers guide and the temperature guide (about 100 times) and i just cant figure out how the offsets work. TAT, SpeedFan, and CoreTemp give me about the same Tjunction, within a degree or two. so I assume they are reading correct.

As for TCase, the BIOS and SpeedFan read about the same also (@ Idle of course).

Now, when i compare them to the temp guide, it seems my temps are upside down. If i use an offset for the Tcase, than it goes below ambiant, which isn't right. And if i offset the Tjunction in SpeedFan that contradicts TAT.

I don't want to guess, or just fudging numbers to make me feel better. I want to push my computer beyond stock voltages, but I'm not sure where to go from here? (CompuTronix?) Should I just be concerned with Tjunction and forget about Tcase temps?

Ambient = 25
Chipset = 975
C2D = E6400
CPU Cooler = Thermaltake Big Typhoon
Frequency = 2666
Load = TAT
Motherboard = Intel D975BXB2
Vcore = 1.29 (speedfan)



Testing

Vcore = Manual
C1E / EIST = Disabled
CPU Fan = Manual, 100%
Computer Case Fans = Manual 100%
Computer Case Covers = Installed
Primary Test = TAT @ 100% 10 Minutes




Results

Tcase = 32c Idle, 50c Load (SpeedFan)
Tjunction (TAT) Hottest Core = 28c Idle, 46c Load (SpeedFan) Hottest Core = 24c Idle, 48c Load

 

[graysky]

Yes, only use tjunction and keep them under 65 °C. Also remember that your tjunction values will raise about 2-1/2 °C for every 1 °C of room temp. Plan your o/c accordingly since summer is just around the corner.

You can measure your tjunction either with TAT or my new favorite RMClock which has much more features including logging over TAT.

If you wanna drop your temps by 5-10 °C you can consider lapping your HS and IHS on the CPU.

Link to my HS lapping thread
Link to my Q6600 IHS lapping thread

 

[CompuTronix]

2tonedug, TAT's temps aren't 100% correct for every hardware / firmware configuration. From the Guide:

Troubleshooting

(E) Any hardware and / or software may misreport Tcase and / or Tjunction temps.

Although TAT's thermal loading is absolute, don't allow it's temps to run you aground, especially if your E6400 has L2 stepping.

If i use an offset for the Tcase, than it goes below ambiant, which isn't right. And if i offset the Tjunction in SpeedFan that contradicts TAT.

Your Tjunction Idle temps show some non-linearity which doesn't closely conform to Parameters, however the most important consideration is the relationships between Load temps. Also from the Guide:

Interpretation

Since Intel's Thermal Analysis Tool (TAT) is a Notebook tool, and desktop C2D's have an integrated heat spreader, TAT will typically indicate ~ 2c lower than SpeedFan.

The above context refers to Load temps, so disregard TAT's Idle temps.

Ambient = 25
Chipset = 975
C2D = E6400
CPU Cooler = Thermaltake Big Typhoon
Frequency = 2666
Load = TAT
Motherboard = Intel D975BXB2
Vcore = 1.29(speedfan)

Testing

Vcore = Manual
C1E / EIST = Disabled
CPU Fan = Manual, 100%
Computer Case Fans = Manual 100%
Computer Case Covers = Installed
Primary Test = TAT @ 100% 10 Minutes

Results

Tcase = 32c Idle, 50c Load (SpeedFan)
Tjunction (TAT) Hottest Core = 28c Idle, 46c Load (SpeedFan) Hottest Core = 24c Idle, 48c Load

Configure a -5c Tcase Offset, and +10c Tjunction Offsets in SpeedFan, which are appropriate relative to your Ambient, CPU cooler, and Vcore, and will indicate a Tcase / Tjunction Load Delta of 13c. This will increase to ~ 15c as Vcore and OC are increased. Remember to click on "Show in Tray" Core 0.

Corrected Results:

Tcase = 27c Idle, 45c Load (SpeedFan)
Tjunction (SpeedFan) = 34c Idle, 58c Load

Hope this helps,

Comp 8)

 

[graysky]

@CompuTronix: Isn't TJunction a constant for a given processor (85 °C for C2D and 100 °C for Quads)? I've read that a core temp = TJunction - DTS where DTS is the values reported by on internal DTS. See this thread for the discussion from uncleweb.

Thanks.

 

[2tonedug]

Great. Thanks a lot CompuTronix. So really TAT will just be used as a tool for putting a load on the CPU, not for taking temperature measurements.

 

[CompuTronix]

Isn't TJunction a constant for a given processor (85 °C for C2D and 100 °C for Quads)? I've read that a core temp = TJunction - DTS where DTS is the values reported by on internal DTS. See this thread for the discussion from uncleweb.

graysky, thank you for your input. I've read that thread as well as many others debating Tjuntion and temps in general. Intel's documentation and email / Forum responses are about as clear as mud, and about as evasive and forthcoming as the CIA, so don't get too wrapped up in it. Here's how it works: Tjunction = Junction Temperature = Core Temperature. Tj Max = 85c or 100c. From the Guide:

Thermal Specification:

** For processors without integrated heat spreaders such as mobile processors, the thermal specification is referred to as the junction temperature (Tj). The maximum junction temperature is defined by an activation of the processor Intel® Thermal Monitor. The Intel Thermal Monitor’s automatic mode is used to indicate that the maximum TJ has been reached.

Interpretation

** The second part of the spec refers to mobile processors without an integrated heat spreader, measured by internal Digital Thermal Sensors. Since Intel's Thermal Analysis Tool (TAT) is a Notebook tool, and desktop C2D's have an integrated heat spreader, TAT will typically indicate ~ 2c lower than SpeedFan. These are the dual Core temperatures measured within the hot spot of each Core. Thermal Junction temperatures of 75c is hot, 70c is warm, and 65c is safe. The dual Thermal Junction sensors are how Tjunction is measured, and are the dual Core temperatures displayed in TAT, and SpeedFan: Core 0 / Core 1.

Hope this helps,

Comp 8)

 

[CompuTronix]

So really TAT will just be used as a tool for putting a load on the CPU, not for taking temperature measurements.

2tonedug, yes, that is the intention. If TAT's temps make sense, then it's useful as a reference. If they don't seem appropriate relative to the Variables, then don't allow it run you aground.

Enjoy your rig,

Comp 8)