Contemporary Architectures Flashcards
Is using clock speed as a measurment of performance good ?
No because it has plataued at 3.5GHz and is not very comprihensive of the systems capabilities
What is CPU time ?
The time it takes the CPU to execute one program
How doe we calculate CPU time ?
CPU time = clock speed * cycles per instructiuon * instructions per task
What is MIPS ?
Millions of instructions per second
sockets * cores per socket * clock *instructions per socket
What is FLOPS ?
Floating point operations per second
sockets * cores per socket * clock * FLOPS per cycle
What is Amdahl’s law ?
Potential speedup of a complete system due to speeding up one component by factor of N
speedup = old run time / new run time
What are benchamrks ?
A program that tests the compnents of a computer to measure the performance and compare to others
What is Goodhart’s law ?
“When a measure becomes a target, it ceases to be a good measure”
What is the x86 Architecture ?
A family of CISC architectures
Lots of instructions (3000+)
What is the history of x86 ?
William shockley –> Shockley transistors
Traitorous eight –> Fairchild
Moore and Noyce –> Intel
Sanders –> AMD
What is the boot process in modern x86 CPUS ?
Power-up, Bootloader, BIOS, OS loader
What is secure boot ?
Part of the UEFI standard
Locks the UEFI down to boot only one OS
What is the philosophy behind RISC ?
The complex instructions aren’t being used.
Count the frequencies of actual instruction uses, then reduce instruction set to optimis most common needs
Name some examples where RISC is used
Android, debian, Ubuntu, ARM chips and mobile devices
What is RISC-V ?
A fully open source ISA
RISC style instructions
Base instruction set
How many registers in RISC-V ?
0 - 32, control, status registers, stack pointer, and 32 optional registers
