03 Microprocessors Flashcards
What is the microarchitecture of a CPU?
It is what determines features such as speed range, number of cores, etc.
What is hyperthreading and on which processors can this feature be found?
Hyperthreading is a feature that, when enabled, makes a four core processor act as if it was an eight core processor. Essentially, it makes the processor act as if it had double the number of cores that it actually does. Hyperthreading is only available on Intel processors.
How is CPU speed measured?
CPU speed is measured in hertz, which means cycles per second.
What does 1 GHz mean and on what component of a PC would one find this specification?
1 GHz means 1 billion cycles per second. This measures the processing speed of the CPU.
What does it mean for a CPU to have multiple cores?
It means that there are multiple CPUs on a single chip.
Why do nearly all computers load programs from the hard drive to RAM before processing with the CPU?
While it is possible for the CPU to process information directly from the hard drive, the speed of the hard drive is very slow compared to The speed of the CPU. Therefore programs run much more efficiently when they are transferred to RAM first, and from RAM to the CPU. The speed of the hard drive is thousands of times slower than the speed of RAM, and the speed of ram is slower than the speed of the CPU. So to really take advantage of the speed of the CPU, Ram is used.
What is CPU caching and why is it used?
CPU caching refers to the inclusion of small bits of superfast RAM built into the CPU chip itself. This improves CPU performance even better than using standard system ram as the only intermediary between the CPU and the hard drive. Standard system ram is still significantly slower than the CPUs processor speed. Therefore adding small bits of ram into the processor itself which run much faster than the standard system ram improves CPU performance. It helps the CPU to work with more lines of code at once and hence to be more efficient. It would slow down the CPU to have to wait until later to jump from One line of code to another that is very “far away” in the program script. This prevents slowdowns of the CPU when dealing with lines of code that refer to other lines of code that have not yet been loaded by the CPU. With cache, the CPU can “See” more lines of code at once, which helps it to be more efficient. Level 1 cache is just as fast as the CPU. Level 2 cache spills into level 1 cache and is about half as fast as level 1 cache. Level 3 cache, if included on a CPU chip, is about as fast as the motherboard.
What is level one cache?
It is a super small but superfast amount of ram that is built into CPUs. It runs as fast as the CPU does. If it were the size of the systems main random access memory, it would cost about as much is a car does. That is why there is so little of it. It is the level of cache that is closest to the processor cores.
What is level two cache?
Level to cache is included on CPUs as a second layer of caching. Level one cache is closest to the processor cores and level two caching is second in line.
What is level three cache?
Level 3 cache is the slowest of all cashing levels in a processor. It is about as fast as the motherboard. It is the most outer layer of caching being farthest from the processor cores. Level 3 cache feeds into level 2 cache which feeds into level one cache which feeds into the processor cores. Also, sometimes secondary levels of cache feed directly into the processor cores.
What is the difference between dynamic and static ram?
Dynamic ram is much less expensive for larger amounts of storage and is used as standard system ram. Static ram is much more expensive even for small amounts of storage. Static ram is used for caches in CPUs.
Explain the debate [between AMD and Intel] over the size of processor caches.
Larger caches are beneficial because they can store many branches of code so that the processor does not have to sit around waiting for a reference to a distant line of code to finally become accessible. However larger caches have the disadvantage of running slower and it being harder to find lines of code within them. Smaller caches make it easier to find stuff within them.
How much ram can be installed on a system that is using 32-bit computing? 64-bit computing?
4 GB of RAM is the maximum for a 32 bit computing environment. Much larger amounts of ram can be used with a 64 bit computing environment.
What is a CPU extension?
A CPU extension is a feature that CPU manufacturers add to CPUs such as Long integer mathematics, 3-D support, power management features, etc.
What is virtualization support on a CPU?
Virtualization support is a CPU extension which makes virtualization work better. For example, it will set aside specific parts of the processor for virtual machines. Virtualization support can be enabled by going into bios settings.
