3.4 - CPU Features

Question 1

Operating system technologies

Answer 1

• 32-bit vs. 64-bit - Processor specific
• 32-bit processors = 232 = 4,294,967,296 values
• 64-bit processors = 264 = 18,446,744,073,709,551,616 values
  – 4 GB vs. 17 billion GB
  – The OS has a maximum supported value

Question 2

Operating system technologies

Answer 2

• Hardware drivers are specific to the OS version (32-bit / 64-bit)
  – 32-bit (x86), 64-bit (x64)
• 32-bit OS cannot run 64-bit apps
  – But 64-bit OS can run 32-bit apps
• Apps in a 64-bit Windows OS
  – 32-bit apps: \Program Files (x86)
  – 64-bit apps: \Program Files

Question 3

Advanced RISC Machine (ARM)

Answer 3

• CPU architecture developed by Arm Ltd.
  – They design the chip, others license and build
• Simplified instruction set
  – Efficient and fast processing
  – Less power
  – Less heat
• Traditionally used for mobile and IoT devices
  – The lines are constantly blurring

Question 4

Processor cores

Answer 4

• Dual-core / Quad-core / Octa-core / Multi-core
• Multiple cores
  – Each core has its own cache
  – The entire chip may have a shared cache

Question 5

Multithreading

Answer 5

• Hyper-Threading Technology (HTT)
• One CPU, acts like two
• Doesn’t actually work as fast as two
  – 15% to 30% performance improvement
• Operating system must be written for HTT
  – Windows XP and later (any modern OS)

Question 6

Virtualization support

Answer 6

• Run other operating systems within a single
  hardware platform
  – Multiple operating systems share physical
  hardware components
• Virtualization in software was limited
  – Performance and hardware
  management challenges
• Virtualization added to the processor
  – Hardware is faster and easier to manage
  – Intel Virtualization Technology (VT)
  – AMD Virtualization (AMD-V)