Add information about CPU dies to topology section in the manual.

Author: wolfpld

manual/tracy.md

@@ -12,7 +12,7 @@ The user manual
 
 **Bartosz Taudul** [\<[email protected]\>](mailto:[email protected])
 
-2025-07-13 <https://github.com/wolfpld/tracy>
+2025-07-15 <https://github.com/wolfpld/tracy>
 :::
 
 # Quick overview {#quick-overview .unnumbered}
@@ -2343,9 +2343,13 @@ You may disable context switch data capture by adding the `TRACY_NO_CONTEXT_SWIT
 
 Tracy may discover CPU topology data to provide further information about program performance characteristics. It is handy when combined with context switch information (section [3.16.3](#contextswitches)).
 
-In essence, the topology information gives you context about what any given *logical CPU* really is and how it relates to other logical CPUs. The topology hierarchy consists of packages, cores, and threads.
+In essence, the topology information gives you context about what any given *logical CPU* really is and how it relates to other logical CPUs. The topology hierarchy consists of packages, dies, cores, and threads.
 
-Packages contain cores and shared resources, such as memory controller, L3 cache, etc. A store-bought CPU is an example of a package. While you may think that multi-package configurations would be a domain of servers, they are actually quite common in the mobile devices world, with many platforms using the *big.LITTLE* arrangement of two packages in one silicon chip.
+Packages contain cores and shared resources, such as a memory controller or L3 cache. They also include a common connector to access peripheral hardware and receive power. An example of a package is a store-bought CPU.
+
+Historically, a CPU would contain all its cores, controllers, and caches in a single piece of semiconductor called a die. More advanced CPU designs that have recently appeared may split the available cores across two or more dies. An additional die may be invisible to the user and facilitate communication between the cores. This is an important detail to consider when profiling because the latency of core interactions will differ between cores that are physically close together on a single die versus cores that need to communicate through die interconnects.
+
+While you may think that multi-package configurations would be a domain of servers, they are actually quite common in the mobile devices world, with many platforms using the *big.LITTLE* arrangement of two packages in one silicon chip.
 
 Cores contain at least one thread and shared resources: execution units, L1 and L2 cache, etc.
 

manual/tracy.tex

@@ -2680,9 +2680,13 @@ \subsubsection{CPU topology}
 
 Tracy may discover CPU topology data to provide further information about program performance characteristics. It is handy when combined with context switch information (section~\ref{contextswitches}).
 
-In essence, the topology information gives you context about what any given \emph{logical CPU} really is and how it relates to other logical CPUs. The topology hierarchy consists of packages, cores, and threads.
+In essence, the topology information gives you context about what any given \emph{logical CPU} really is and how it relates to other logical CPUs. The topology hierarchy consists of packages, dies, cores, and threads.
 
-Packages contain cores and shared resources, such as memory controller, L3 cache, etc. A store-bought CPU is an example of a package. While you may think that multi-package configurations would be a domain of servers, they are actually quite common in the mobile devices world, with many platforms using the \emph{big.LITTLE} arrangement of two packages in one silicon chip.
+Packages contain cores and shared resources, such as a memory controller or L3 cache. They also include a common connector to access peripheral hardware and receive power. An example of a package is a store-bought CPU.
+
+Historically, a CPU would contain all its cores, controllers, and caches in a single piece of semiconductor called a die. More advanced CPU designs that have recently appeared may split the available cores across two or more dies. An additional die may be invisible to the user and facilitate communication between the cores. This is an important detail to consider when profiling because the latency of core interactions will differ between cores that are physically close together on a single die versus cores that need to communicate through die interconnects.
+
+While you may think that multi-package configurations would be a domain of servers, they are actually quite common in the mobile devices world, with many platforms using the \emph{big.LITTLE} arrangement of two packages in one silicon chip.
 
 Cores contain at least one thread and shared resources: execution units, L1 and L2 cache, etc.