Core Temp lists a temperature for each core the processor actually exposes, plus the CPU fields around that reading. This page is the breakdown. The Windows download is version 1.21, dated 3 October 2026.
The main window is a processor report, not a board sensor list. You get the model, socket, frequency, multiplier, VID, revision, lithography, CPUID, and TDP. Under that, each core has the current temperature, the minimum, the maximum, and the load. Tj. Max stays visible so you can see how close a core is to the junction limit the vendor defined.
Core i7-2600K, four cores, eight threads, 4298 MHz, VID 1.3661 V, 32 nm, TDP 95 W. Core 2 reached 65°C. Select to enlarge.
On Ryzen, the same window can show Tdie and Tccd beside the cores. The home page screenshot of a Ryzen 9 9950X (Granite Ridge, 16 cores, 4 nm, TDP 170 W) has Tj. Max at 95°C, Tdie at 47°C, and cores between 26°C and 30°C at 2% load. Those are different sensors. A single package number would hide that.
Version 1.19.5 added per-CCD and per-core readings for most Zen models, including Zen 4 and Zen 5 desktop and laptop parts and Threadripper 7000 and 9000. It also added an effective clock, a core picker for frequency, and P-core / E-core tooltips on Intel hybrid chips.
How the number is calculated
The reading does not come from a diode on the motherboard. Intel, AMD, and VIA publish different registers. Core Temp follows those methods. A question mark after a value means that sample was not marked valid. Some 45 nm Core 2 chips do not report temperatures below about 30°C or 40°C.
Published temperature math used by Core Temp.
Processor
What is read
Temperature
Intel, from Core 2 onward
Tjunction, then a delta in a model-specific register. From Nehalem, Tj. Max itself can be read. The delta field is 7 bits, so the theoretical range is 0 to 127°C.
Tj. Max minus the delta
AMD K8 (Athlon 64, early Opteron, Sempron)
A register in the CPU northbridge, then the formula AMD published for that generation.
Register value minus 49
AMD K10 and many later package sensors
Phenom, Phenom II, and related Opteron parts often expose one sensor per processor, not one per core.
Register value divided by 8
AMD Zen
Current builds add per-CCD and, on most models, per-core readings, plus TDP and Tj. Max detection on most Zen parts.
Shown per CCD and per core when the model supports it
VIA
An absolute Celsius value from the core sensor. No conversion step. Tj. Max is usually 70°C on desktop parts and 90°C on mobile and low-power parts.
The sensor value, in Celsius
Logging and the grapher
Logging can be turned on and off, with a separate interval for reading temperatures and for writing the log. The file is plain text meant to be opened in a spreadsheet. Version 1.21 fixes a custom log path that was not applied when the program started. You can also write overheat-protection events to the Windows Event Log.
Core Temp Grapher is a separate add-on, as a plugin DLL or a standalone exe. It draws load and temperature per core. The shot below is the older sidebar gadget on a Core i3-540: clock, Tj. Max, RAM, two core bars, and a small history graph.
Gadget view: Core i3-540, 1604 MHz, Tj. Max 105°C, core 0 at 33°C / 16%, core 1 at 36°C / 11%, RAM 2784 of 7864 MB. Select to enlarge.
The Windows 7 sidebar gadget and the Windows Media Center add-on are older companions for Vista and Windows 7. They need Core Temp running. They are not part of the 1.21 installer.
Notification tray
Temperatures can stay in the Windows notification area so the main window does not have to. Version 1.21 redesigns the tray configuration dialog and fixes missing icons and icon order. The same build lets the Logitech G15 applet show up to 10 lines in the built-in font when the date and time line is turned off.
Overheat protection
You can set a temperature that triggers a warning, hibernate, or shutdown. The warning can be disabled. Version 1.21 makes the overheat message the top-most window so it is not hidden behind a full-screen job. If the PC is unattended, hibernate or shutdown is the action that matters. Pair it with the overheat guide if the warning repeats on every sample.
Plugins and shared memory
Plugins and other programs share one data layout. The current structure version is 2. Later versions are meant to extend it without breaking older readers. Temperatures follow the Fahrenheit switch and the "distance to Tj. Max" switch. TDP and power arrays are valid only when their flags say so.
Fields other programs can read from Core Temp shared memory.
Field
What it holds
Per-core temperature
Up to 256 temperature values
Per-core load
Load percentage for each core
Tj. Max and TDP
Per processor, when the chip reports them
Frequency
CPU speed, FSB or reference clock, and multiplier, including per-core multipliers
VID and power
VID, plus power if the power flag is set
Name and scale
CPU name, core count, CPU count, Fahrenheit flag, delta-to-Tj-Max flag
People have reported that older plugins are less reliable on the 64-bit build. If a plugin does not load, use the plugin guide before you replace Core Temp.
Remote and gadget views
A network plugin can publish the same processor status to another program, which is how the phone-style monitor works: machine name, online or not, model, clock, VID, Tj. Max, and a bar per core. The shot below is an Intel Core i3-540 (Clarkdale) at about 1203 MHz, with core 0 at 37°C / 17% and core 1 at 39°C / 21%.
Remote status for a machine named Main. Select to enlarge.
Dark mode for the main program needs Windows 10 or newer. It does not repaint every old dialog. If a language file does not change the menus, the language guide is the next stop.
Core Temp