CPU Performance and Caches Flashcards
What are the most common factors that affect CPU performance?
Clock speed, Processor cores and Cache
Why might a 4-core CPU perform the same as a 1-core CPU while running a program?
The program may not have been designed to take full advantage of all 4 cores.
Why is the cache more useful for frequently used data than the RAM?
The cache is closer, and faster, reducing wait times for data to be fetched and stored.
What is a level 1 cache?
A level 1 cache is the faster type, each CPU core has its own but its storage size is around 2-256KB
What is a level 2 cache?
A level 2 cache is very fast, slower than a level 1 and each core has its own. The size is around 256KB - 8MB
What is a level 3 cache?
Level 3 cache is the slowest type of cache but still faster than RAM. There is one per CPU (all the cores share it) and it stores 4 - 50MB
Which cache is the main decider in the performance of the CPU?
The level 2 cache, it is accessed 90 percent of the time and can greatly reduce the amount of time that the CPU has to wait for data.
What is an embedded computer?
An embedded computer is something used to control a device with simple outputs. It is a single microprocessor that includes RAM, ROM, and a CPU
What embedded functions might a car use?
Cruise control, engine cooling fan, interior fans and temperature, interior lighting, rear cameras and remote parking, infotainment systems (emtertainment, information, satnav), engine control unit (ECU)
Where is a program stored in an embedded system?
The ROM, this makes them very reliable as the software cannot be changed and cannot afford to have bugs.
What is an embedded system (def)
A computer that is an integral part in a mechanical or electrical system.
