Thread: Core i7 and Core 2 Temperature Guide

Preface:

The function of this channel is to offer over clocking enthusiast with an accepting of thermal relations, so that temperatures can be uniformly tested, accurately calibrated, and properly monitored. This Guide supports air cooled Core i7 and Core 2 desktop processors. All temperatures are referenced to Standard Ambient 22c.

Scope:

This point is projected for transitional to advanced users. Although certain strict definitions have been relaxed to simplify concepts, this Guide contains detailed technical information. Information of hardware configurations, BIOS settings, motherboard manuals and terminology is required, as well as familiarity with CPU-Z, Prime95 and Speed Fan.

Section 1: Introduction

Core i7 and Core 2 processors have 2 different types of temperature session; a CPU case (not computer case) Thermal Diode centered under the Cores and Digital Thermal Sensors located on each Core. The case Thermal Diode measures Tcase (Temperature case), which is CPU temperature, and the Digital Thermal Sensors measure T-junction (Temperature junction), which is Core temperature. Since these sensors measure 2 distinct thermal levels, there is a 5c temperature difference between them, which is Tcase to T-junction Gradient. C2Q's have 1 Tcase and 4 T-junction sensors, while C2D's have 1 Tcase and 2 T-junction sensors. Uncalibrated default temperatures are seldom perfect.

Intel provide absolute stipulation for Tcase (CPU temperature), but only fractional stipulation for T-junction (Core temperature), which has caused much confusion and debate in the over clocking community concerning test methods, temperature monitoring utilities and accuracy. The monitoring utilities provided by motherboard manufacturers monitor CPU temperature, while some popular freeware utilities monitor Core temperatures. The most accurate Core temperature monitoring utility available is Real Temp - which has several unique and innovative features, and is recommended for users interested in monitoring Core temperatures only.

Speed Fan monitors Tcase (CPU temperature) and T-junction (Core temperature), which can be calibrated for each session, while also on condition that a full compliment of peripheral temperatures, voltages and fan speeds. Speed Fan is very flexible and configurable, which includes thermal alarm settings and graphical charts, as well as many other excellent automated features for creating a cool yet quiet over clocked computer. When configured with this Guide, Speed Fan is recommended for over clocking enthusiasts interested in achieving the most precise custom temperature calibrations, while observing vital system performance information.

Section 2: Specifications

In view of the fact that temperatures can be baffling to decipher and compare, it is very important to be specific, so when listing Idle & Load test Results, it is also necessary to list the Variables as shown below:

Computer can be recognized by the product code on the retail box, the Integrated Heat Spreader on the CPU, and by CPU-Z. Use CPU-Z to read the Revision field below the Stepping field, and then record the characters. Use the following link to match the CPU with Intel's Space for VID Voltage Range, Core Stepping, Thermal Design Power, and Thermal Specification (which is maximum CPU temperature, not maximum Core temperature).

• Intel Processor Spec Finder:

Intel Thermal Specifications:

It is deliberate at the geometric center on the topside of the processor integrated heat spreader. Thermal condition revealed is the extreme case high temperature at the highest Thermal Design Power (TDP) value for that processor. For processors without integrated heat spreaders such as mobile processors, the thermal requirement is referred to as the junction temperature .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.

Section 3: Interpretation

. The initial part of the space refers to a solitary measuring point on the Integrated Heat Spreader (IHS). Since a thermocouple is embedded in the IHS for Intel laboratory testing only, CPU temperature is instead measured using a Thermal Diode centered under the Cores. Maximum case temperature (Tcase Max) is determined by Space. The CPU case Thermal Diode is how Tcase is deliberate, and is the CPU temperature displayed in BIOS and Speed Fan

• Tcase Max is a requirement, Tcase is a temperature.
The second part of the spec refers to mobile CPUs lacking built-in Heat Spreaders even though desktop CPUs contain an IHS; both variants measure the hot spots on every Core by means of Digital Thermal Sensors .Maximum junction temperatures (T-junction Max) are determined by Intel factory Calibrations. The Digital Thermal Sensors are how T-junction is deliberate, as well as are the Core temperatures display in Speed Fan.

• T-junction is a temperature, T-junction Max is a requirement

Section 4: Thermal Flow

Heats originate within the Cores, where T-junction sessions are situated on the hot spots of each Core. Most of the heat dissipates from the top of the Cores through the Integrated Heat Spreader and CPU cooler to air inside the CPU. Some of the heat dissipates from the bottom of the Cores through the CPU case, which creates a 5c thermal Gradient toward the center of the substrate, where the Tcase sensor is located. This heat then dissipates through the socket and motherboard to air inside the computer. Safe and sustainable temperatures are determined by CPU cooling effectiveness, computer case cooling efficiency, ambient temperature, Vcore, clock speed and Load.

Section 5: Findings

(A) Tcase is require on the CPU remove from the CPU case Thermal Diode as an analog plane, which is rehabilitated to a digital cost by the super Input or Output chip on the motherboard. The digital worth is BIOS Calibrated and display by temperature software. Motherboard BIOS Calibration affects the accuracy of Tcase, or CPU temperature.

(B) T-junction require by the Cores from Thermal Diodes as analog level, which are transformed to digital cost by the Digital Thermal Session (DTS) on each Core. The digital values are Factory Calibrated and displayed by temperature software. Intel Factory Calibration affects the accuracy of T-junction, or Core temperatures.

(C) Tcase and T-junction are together acquired by Thermal Diodes. Tcase and T-junction analog to digital (A to D) conversion are executed by break up strategy in unlike location. BIOS Calibrations from motherboard manufacturer, Factory Calibrations from Intel, and accepted temperature utilities are commonly inaccurate.

(D) The pattern that Intel chains in the Processor Spec Finder for Core i7 and Core 2 desktop processors is Tcase Max, not T-junction Max. Ambient to Tcase Delta has known Offsets which vary with power dissipation and cooler effectiveness, and is calibrated at Idle using a standardized Test Setup.

(E) Intel provides only fractional certification for T-junction Max on desktop processors. For Throttling and thermal Shutdown protection, Intel uses the Digital Thermal Sensors (DTS) to monitor Delta to T-junction Max, which is a relative value that varies from Core to Core, and is not an absolute temperature.

(F) T-junction Max must be known to calculate absolute Core temperature, which is T-junction. Popular temperature monitoring utilities may wrongly estimation is hidden T-junction Max values, which results in too much Core temperatures and inconsistent Tease to T-junction Gradients among Ci7 and C2 variants.

(G) Obtainable test information from several Intel identification as well as plentiful independent source show Tcase to T-junction Gradient has a known Offset which is 5c, and is calibrated at Load using a standardized Test Setup.

Section 6: Scale

Secure and sustainable temperatures vary according to Space. The temperature balance shown below illustrates the Delta between Idle and Load, and the 5c Gradient between Tcase and T-junction. Although the 5c Gradient is relatively consistent, Tcase and T-junction tend to converge at Idle and diverge at Load due to Variables such as Vcore and CPU cooler efficiency. Low Vcore and clock may cause Tcase to T-junction Gradient to indicate less than 4c at Idle, while high Vcore and over clock may cause the Gradient to exceed 6c at Load.

But temperatures increase beyond Hot Scale, then a few degrees below T-junction Max, Throttling is activated. The Digital Thermal Sensors (DTS) are used to trigger Intel's technology for incidence, multiplier and Vcore Throttling within individual Cores. If Core temperatures exceed T-junction Max, then Shutdown occurs. Since Tcase indicates CPU substrate temperature only, it is not used for Throttle or Shutdown activation; however, as Tcase Max will be exceeded before T-junction Max is reached, Tcase Max is always the limiting thermal specification.

Use CPU-Z (see Section 8) to read processor in order to counting the Revision field below the Stepping field, then chooses a Scale below which matches the CPU being tested. Scales are ordered from top to bottom Tcase Max, according to Intel Thermal Specifications.

Section 7: Tools

Hardware:

A trust inside analog or digital thermometer will be looked-for to measure Ambient. The correctness of this device and dimension will determine the in general accuracy of the Calibrations.

Software:

Computer and Speed Fan determine to be worn to Calibrate Tcase at Idle. Prime95 will be used in addition to CPU-Z and Speed Fan to Calibrate T-junction at Load. Speed Fan will then be used to permanently monitor temperatures.

Prime95 - Once run the programmed initial time, it is necessary to click on Advanced, and then click on Round off checking so that errors caused by instabilities will be flagged as they occur. Prime95 will automatically thread all Cores, and will expose insufficient CPU cooling and computer case cooling, or excessive Vcore and over clock. At no other time will a CPU be as heavily loaded, or display higher temperatures, even when OC'd during worst-case loads such as gaming or video editing. Prime95 can be used with Speed Fan to observe CPU temps, while stress testing for system stability. During single threaded gaming and applications, Core 0 typically carries heavier loads and higher temps than other Cores.

Section 8 Speed Fan - Especially flexible and configurable, Speed Fan is the ideal temperature monitoring utility because Tcase and T-junction can be calibrated. Speed Fan detect and label thermal session according to a variety of motherboard, chipset and super I/O chip configurations, so the label for Tcase can be CPU, Temp 1, Temp 2, or Temp 3. Even if Tcase is labeled as CPU, it is still necessary to confirm the identity of Tcase prior to performing arts as Calibrations.

Frequently set up and stop Prime95 is Small FFT's at 15 second of interval, while observe which Speed Fan temperature scales with an Idle to fill Delta parallel to the Cores. This will identify the label corresponding to Tcase. Labels can later be renamed using the Configure button. See Section 11.

If a temperature illustrates a flame icon, this specifies alarm limits which need adjustment. Make use of the Reset button to set CPU as well as Core temp alarms to Warm Scale. If a temperature shows Aux 127, this is just an unassigned input which can be disabled by means of the Configure button. See Section 11.

Section 9: Calibrations

Defaulting temperatures are hardly ever been correct. The following two part procedure is designed to achieve two objectives:
Present least Ambient to Tcase Delta used for correct Tcase Idle Calibration. Supply utmost Tcase to T-junction rise for accurate T-junction Load Calibration.

It is favored, but not necessary, that Calibrations be conducted as close to 22c Standard Ambient as possible, which provides a normal temperature ceiling, and maintains ecological constancy for comparing Idle and Load temperatures among processor variants and system platform.

(A) Compute Ambient close to the CPU case air intake, clear of warm tire out. A trusted indoor digital thermometer will be sufficient. The correctness of this device and measurement will determine the overall accuracy of the Calibrations.

(B) Boot addicted to window. Shut all programs, setting processes, Screen Savers, SETI, Folding and Tray software. Press Ctrl-Alt-Delete, click on Task Manager, and then click on the Performance tab to confirm CPU Usage is less than 1%. Use the application and process tab to close programs if necessary.

(C) Unlock computer and Speed Fan. View computer for Intel's Speed step to reduce Core electrical energy, Core Speed and Multiplier to minimum values. Observe Speed Fan, allow 10 minute at Idle to ensure that temperatures decrease to minimums, and then record Tcase Idle.

CPU and cooler combination which are mutually lap by subtract 1c from Tcase Idle.

Organize Offset alteration as shown in Section 11. Since the Tcase session was planned to be linear from Idle to Load, Tcase Load will also be accurate.

Create Prime95 Small FFT's. Observe CPU-Z for Intel's Speed step to increase Core Voltage, Core velocity and Multiplier to Stock morals. Observe Speed Fan. Heat saturation is typically reached within 7 to 8 minutes, so allow 10 minutes at Load to assure that temperatures increase to maximums, and then record T-junction for each Core.

End of Prime95, and then permit the structure to Idle for 10 minutes. T-junction Idle should be ~ 4c higher than Tcase Idle.
T-junction session were intended by to be linear at high temperatures for Throttle and Shutdown defense, so T-junction Idle could indicate too low or too high. Many 45 nanometer variants have faulty sensors that "stick" and might not idle below 50c. Sensors can be tested using Real Temp -

Condition T-junction Idle is not higher than 4c .Tcase Idle, then use Tcase Idle for perfect idle temperature.

Section 10: Results and Variables

Prime95 little FFT's be supposed to confirm that T-junction, if temperatures do not get together the Parameters, then make sure the Test Setup and repeat Parts 1 and 2. Remember that Tcase and T-junction tend to meet at Idle and deviate at Load due to Variables such as Vcore and CPU cooler competence. Low Vcore and clock may cause Tcase to T-junction Gradient to indicate less than 4c at Idle on, while a heavily over clocked Core i7 with high Vcore may exceed Tcase to T-junction Gradient of 6c at Load.

But temperatures are allowed to add to beyond burning Scale, then a few degrees below T-junction Max Throttling is activate. If Core temperatures top T-junction Max, then power cut occurs. Since Tcase Max will be exceeded before T-junction Max is reached, Tcase Max is always the limiting thermal specification.

• It is not optional to repeatedly functioning processors, over clocked or stock, at Hot Scale for reasons of constancy and long life.

• The subsequent example each stand for classical over clocked systems, which have fairly high Vcore settings, yet still maintain Safe temperatures at 100% Workload. Note that Tcase to T-junction Gradient shows 6c at Load due to high Vcore. This is normal and expected; since 5c was Calibrated using a Test Setup standardized for maximum cooling capacity at Stock Vcore, Frequency and Multiplier settings.

At rest to Load Delta will differ from among system owed to inconsistency such as Ambient temperature, Vcore, clock frequencies, sensor linearity, CPU cooling, heat spreader and heat since flatness, thermal compound, computer case cooling, graphics card(s) cooling, and software processes. Excessive background processes running simultaneously may not allow low idle temps. Low Vcore and stock clock may result in low Idle to Load Delta. High Vcore and over clock may exceed 25c Idle to Load Delta, as shown in the Examples above.

Wrongly BIOS Calibrations from motherboard manufacturers, Factory Calibrations from Intel, and popular temperature monitoring utilities often result in Tcase and T-junction inaccuracies. Since Intel's Thermal Diode spec is +1c/-1c, temperatures can still be accurate when Speed Fan is properly calibrated, which should indicate Core temperatures that are within a few degrees of Real Temp.

Section 11: Offsets

Speed Fan is able to be configured to accurate for mistaken Tcase.

(A) Since the Readings tab, click on the Configure button, then click on the advanced tab, and click on the Chip field, openly beneath the tab

(B) After that, set out to Speed Fan’s fitting Program Group, and click on the assist and HOW-TO image. This help file can also be set up by pointed for the filename speed fan.

(C) Below the inside, click on How to arrange, then click on How to set difficult opinion. Read this section, including other interesting options, with emphasis on Temperature x offset.

(D) But extra aid is needed, click on the following link to Speed Fan’s homepage, then click on the Support, Articles, and Screenshots.

While Computer and Core offset have been finished, Speed Fan will be exact. Speed Fan is also enormously helpful for observing temperatures and Vcore using the Charts tab, while thermal benchmarking with Prime95 Small FFT's.

(A) Tcase may be label as Computer, Temp 1, Temp 2 or Temp 3, but is most regularly labeled as Temp 2. Follow Section 8, Note 2 to correctly identify which label corresponds to Tcase.

(B) T-junction is label Core 0 and many of that.

(C) Graphics to be label Core.

(D) Graphics Cards which display a session labeled Ambient must not be used for measure space temperature.

(E) Speed Fan flame images are panic limits which can be used to to Warm Scale using the Configure button.

(F) Speed Fan Aux 127 is an unassigned effort which can be disabling with the Configure button.

(G) Core 0 classically carry heavier loads and senior temps through solitary threaded gaming and application, so Speed Fan should be configured to "demonstrate in Tray" Core 0.

Section 12: Over clocking

Intel's Thermal plan Power space can be exceed by in excess of 50% when CPU frequency is aggressively over clocked, and Vcore is increased to maintain stability. When the default Vcore space is improved by just 10%, it becomes difficult to maintain Safe Scale with high-end cooling. As Ambient temperature increases, Vcore and over clock may need to be decrease.

Each processor is singly in it's over clock possible, voltage patience, and thermal behavior. If the maximum stable over clock is known at 1.35 Vcore (65nm) or 1.25 Vcore (45nm), then ~ 300 MHz of additional over clock remains until Safe Scale is exceeded due to increased Vcore. Each increase of 0.05 volts will typically allow a stable increase of ~ 100 MHz, and will result in a corresponding increase in CPU and Core temperatures of 3 to 4c.

At 1.5 Vcore Max (65nm), or 1.3625 Vcore Max (45nm), or 1.375 Vcore Max (i7) with 100% Workload and 22c Ambient, extremely effectual CPU is cooling and central processing unit case cooling are required to maintain Safe Scale and constancy. Ambient and Vcore are the most dominant Variables affecting temperatures.
For Core i7 over clocking in order, satisfy refer to the following. Intel Core i7-920 over clocking Guide.

For Core 2 over clocking details, please submit to the following, How Over clock Quads and Duals guided v1.6.1.

Heat Score The next matter will make possible users to estimation cooling, competence, classify problem areas, and visualize how environment and system configuration impacts real-world thermal performance. Graphics cards which recirculate heat are a major cause of high temps in gaming rigs; therefore, cards designed with Dual-Slot rear exhaust are preferred.

Troubleshooting

A momentous proportion of 45 nanometer processors are being described with faulty DTS sensors, where one or else the entire Cores won't reduce to low inactive temperatures. Offsets among Cores exceeding 10c are also being reported. Sensors can be tested by means of Real Temp –

(A) Vcore will naturally sink at least 0.025 volts below completely loaded.

(B) Offset stuck between Cores of up to 5c for Quad's and 3c for Duo's are usual.

(C) Very few hardware and software may misreport T-junction temps.

(D) BIOS updates resolve influence the correctness of Tcase, but will have no affect on T-junction.

(E) CPU's artificial with convex included Heat Spreaders may indicate high Idle to Load Delta.

(F) Ambient and Vcore are the most leading Variables poignant temperature.

Comments

• This lead may be regularly revised a new processors and information becomes obtainable.

• I wish this helps to get you Core i7 as well as Core 2 temperatures into viewpoint. Thank you for reading.

Thanks for the first-class posts. I appreciate it. Just wondering.

For an E6400 to idle is 40c and 45c at full load is this good?

I have a good heat-sink and I am well within range, but I thought the temps will be lower.

This is the first time I am running a C2D. Just wondering.

Thanks!

Maybe I need to get better thermal grease

At present no matter which like TAT for an AMD CPU?

Tremendous write-up, this clear up a lot of question I had when deception with my e4300.

Fine former thing this morning I remounted the heat sink once more. I used a little unusual method of dispersion my silver compound, but I'm still idling in Windows at just a hair under 50c. When I pushed it at 100% stress with TAT one of the cores climbed as high as 77. Just so frustrating when I see that other people with my fan I getting low 40's.

Drop a line to do seem to be blocked by any other piece; however it can wiggle on the CPU if I push it. Although that seems bad, given the indentions on the bottom of the heat sink and the way these things bolt in I'm not sure if that's not normal. Seems normal. I guess I can contact Zelman and ask for another heat sink.

The only additional thing that I can think of is if my silver thermal complex has gone "bad." Or if it's maybe that my sensors are purely creation bad readings, or maybe I just fail at Zelman?