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Need Help with Speedfan and Tjonction/Tcase

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August 22, 2007 5:39:41 AM

Ok this is the speedfan reading






I am getting when my system is idling. I can't quite make sens of what I am seeing. For starter, the fan rpm is completely out of range. Temp one seems to be corresponding to my Tcase since it's pretty much the same reading I am getting into the bios. What are temp 2 and temp 3 ? , obviously temp 3 can't minus 2. Also core temps seems to be pretty much the same as the reading I am getting from TAT. Also, there seems to be a huge voltage Delta between the 2 cores !



Here some details from my system:
CPU 6850
MB Gigabytes P35C-DSR3
RAM 4 x 1 gig DDR800 Firestix
Arctic Freezer pro

I would appreciate any help regarding those readings
August 22, 2007 3:42:04 PM

Well, I can't help, but I'm having much the same problem. I'm also running a Gigabyte P35 but a slightly different one, and a 6550.

I have one fan that shows its no where near right and one temp that is also set at around -2c as well. Its also not showing the core temperatures either, but it does have a single temp that seems to be related to the CPU but it isn't labled as such.

Core 0 and 1 and temp2 temperatures have to be wrong too, unless you happen to be running this system in a fridge.

So far I haven't found any updates yet for the P35 motherboards for speedfan.
August 22, 2007 5:20:50 PM

Well, I don't know if speedfan "doesn't like" P35 Gigbyte MB or what but results seem confusing to say the least. I also tried PC Wizard which, in this case was rapporting my CPU at 198C which is not very likely. I tried Everest as well and it reports practically the same temperature for the cores which is not possible. Like I said I am really confuse. If my Tcase is around 30-33 then my core temps, if I understand it correctly, should be my Tjonction which is suppose to be about 15 degrees higher than Tcase. Anyways cores temp can't be lower than the room temperature.....
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August 22, 2007 6:07:23 PM

fatcat, fan multipiers and dividers can be configured in SpeedFan, as well as temperature Offsets. Your CPU (Tcase) should Idle just 1c to 2c above Ambient at low Vcore and stock clock, and the Cores (Tjunction) should Idle 12c to 15c higher. Thermal tables in BIOS are typically errant in 5c intervals, so for example, if your Ambient is 22c, then your CPU temp would requires a - 10c Offset for a result of 23c, and your Cores would require a + 25c Offset for a result of 36c / 35c in order to make sense.

Temp 2 and Temp 3 are Motherboard and Chipset temps, which are also offset with incorrect values. Run TAT or Orthos to verify which temperatures scale to what levels, then follow the "Offsets" section of the Core 2 Duo Temperature Guide sticky http://www.tomshardware.com/forum/221745-29-core-temper... to understand how to make the appropriate corrections. Also, the "Charts" in SpeedFan are very useful to view temperature trends while trying to sort out which temps are which.

Lastly, Vcore 1 is the voltage supply to both CPU Cores, and Vcore 2 is actually Vdimm, which is the voltage supply to your memory.

Hope this helps,

Comp :sol: 
August 22, 2007 9:01:09 PM

Thanks for your reply, I will try to make the necessary adjustments. BTW, I have read your guide which is very well written. Concerning that, I have a question. When setting up for the TAT test you suggest that PECI = Enabled. I did not find that in my BIOS, what is it exactly, I found the other settings but not that one.
a b à CPUs
a b K Overclocking
August 22, 2007 9:27:55 PM

Some newer motherboards have BIOS support for PECI, (Program Environmental Control Interface), which alters the method by which CPU temperatures are calculated. Due to differences in CPU Steppings, CPU (Tcase) and Core (Tjunction) temperatures may be "inverted", which confuses even reasonably well informed users. If PECI is present in BIOS, then enabling this feature will typically result in Tcase being properly displayed at a lower value than Tjunction. Although thermal accuracey is enhanced, it is still not gauranteed. Whether PECI is included in a Motherboard's BIOS or not, proper analysis and application of Offset corrections in SpeedFan remain key to achieving accurate temperature values. I will be including new context regarding "Calibrations" in the Guide on my next update.

Hope this helps,

Comp :sol: 
August 27, 2007 10:05:32 PM

Ok I have done some testing and stuff but there is something not clear about temp 1 and temp 2. When using easytune to monitor my hardware it indicates 2 temperatures one is labelled system and the other one is labelled CPU. System temperature seems to be corresponding to Temp 1 and CPU to temp 2. In this case which one is the Tcase ? I'd assume that system temperature is Tcase but I am not sure. Ambient temp. is 25 C right now.
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a b K Overclocking
August 27, 2007 10:28:38 PM

Run TAT or Orthos. Whichever temp 1 or 2 that scales with a Delta similar to the Cores is Tcase (CPU). For example, if the Cores scale from 42c Idle to 62c Load (20c Delta), then you should expect the CPU to also scale from 27c Idle to 47c Load (20c Delta), + / - 3c. Whichever temp 1 or 2 that scales with a lower Delta of perhaps 5c to 10c is "System" or "Motherboard", which could actually be Northbridge Chipset temperature.

Hope this helps,

Comp :sol: 
August 28, 2007 3:28:30 PM

Ok lets see if my reading make sens now :

Idle reading :



10 Minutes of TAT :



And Finally adjusted temps :



Finally, after what you said, I figured that Temp 2 must be my Tcase. The 2 first images were taken with and ambient temperature of 25 C and the last one with an ambient temperature of 23.

A couple of questions, with the adjusted temperatures, when I run TAT my Tjonction temps rise up in the 60-65 range which seem pretty damn high. Normal or not ? Also, I have removed the RPM fan reading as they cannot be adjusted properly, even with the highest divider they are way too high.

Thanks again for you help^.
a b à CPUs
a b K Overclocking
August 28, 2007 8:54:01 PM

fatcat, good Job, however, your temps are not "pretty damned high". Let's take another look at the Guide:


"...TAT will expose insufficient CPU cooling and computer case cooling, or excessive Vcore and overclock. At no other time will a CPU be so heavily loaded, or display higher temperatures, even when OC'd during worst-case / real-world loads. After CPU thermal behavior has been benchmarked with TAT, then Orthos or assorted other programs can be used with SpeedFan to observe less extreme CPU temps, while stress testing for system stability. Orthos Priority 9 Small FFT's simulates 88% of TAT ~ 5c lower. During gaming and applications, Core 0 typically carries heavier loads and higher temps than Core 1.


Scale

The temp scale shown below illustrates the normal ~ 25c Delta between Idle and TAT @ 100% Load, and the typical ~ 15c Delta between Tcase and Tjunction on an example system overclocked with 1.4 Vcore. 50c Tcase and 65c Tjunction are safe and sustainable temperatures.

-Tcase/Tjunction-

--60--/--75--75--Hot
--55--/--70--70--Warm
--50--/--65--65-- N
--45--/--60--60-- O
--40--/--55--55-- R
--35--/--50--50-- M
--30--/--45--45-- A
--25--/--40--40-- L

--20--/--35--35-- Cool..."


As you can see, your temps are now quite normal, and exactly where they should be.

Hope this helps, and enjoy your rig.

Comp :sol: 
August 28, 2007 11:31:13 PM

I see that you have a nice OC going and I am curious as to know what kind of temps your getting running your rig at 3.7. Even more of interest to me is that your running the same heat sink. I haven't OC yet but that's my next step. I'll need help as well in this department since I am a newbie OC'er.
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a b K Overclocking
August 29, 2007 12:05:37 AM

My IHS and HSF are lapped, and as noted in my sig as well as the Guide, I'm using X-23, (also on NB & SB heat sincs & installed NB fan), and NOT AS5 (I guess some still haven't gotten the memo). At 22c temps are mid 50's Tcase / low 70's Tjunction on TAT due to 1.5125 Vcore. Temps are low 50's Tcase / high 60's Tjunction on Orthos with 1.5125 Vcore. Rig is Orthos stable, but I run 3.7 only on Flight Simulator X or when benchmarking. I normally run 3.0 Ghz which allows minimum voltages on all components. I was lucky and recieved an exceptionally good B2 Stepping overclocker.

As I've said many times befroe, there are no solid state devices 100% identical. Every piece of silicon is unique, and as such, has different properties of electronics which include resistance, capacitance, inductance, impedance, and transconductance. Although two consecutive serial number CPU's from the same fabrication, with the same stepping may appear identical, they're yielded from different location on the silicon wafer from which they're manufactured, and like diamonds, each has it's own unique flaws.

Even though their dynamic operational characteristics may be very similar, no two CPU's will overclock to exactly the same stable maximum speed, at the same Vcore, at the same temperature. Additionally, in a multicore processor, one Core will always become unstable before another. The overclock ceiling for the E6600 is typically 3.4 to 3.6 Ghz at 1.5 Vcore with top-of-the-line air cooling.

It's impossible to predict at what clock speed the Cores you have will become unstable as you increase Vcore, but don't feel apprehensive about increasing Vcore when overclocking an E6850. These new G0 Stepping processors are quite robust, however, do not exceed 55c Tcase / 70c Tjunction during Load testing with Orthos, and 60c Tcase / 75c Tjunction with TAT. Just remeber that none of these C2D's come with an overclocking gaurantee. They're all different. Every tweak is a roll of the dice.

Hope this helps,

Comp :sol: 
August 29, 2007 12:17:12 AM

Actually, I am not running a 6600 but a 6850 with the new G stepping. I won't be cranking it as much as I can, at least not at first but probably be comfy with a mild OC at something around 3.5 - 3.6. This shouldn't be a problem since, I have read many times that this CPU can be clock around 3.8 with the stock cooler
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August 29, 2007 12:47:37 AM

I was editing my last paragraph as you posted. I am aware that you're running the E6850 G0 Stepping, however, regardless of what you've read, overclocking CPU frequency to it's highest stable level is accomplished through increasing Vcore (among other items) while maintaining safe CPU and Core temps. Once 1.35 Vcore is reached, Intel's stock cooler has just about reached it's limit. Again, it's not possible to predict what clock speed 1.35 Vcore will yield on your particular E6850, but I assure you that with your ACF7 Pro, which is a very good medium/high-end cooler, your temps will be much, much better than with Intel's stock cooler. The ACF7 Pro will allow you to push past 1.4 and possibly 1.45 Vcore, but at 1.5 Vcore, all aspects of environmental and computer case cooling become critical, and IHS / HSF lapping may even be required.

Hope this helps,

Comp :sol: 
!