Parallel Architectures Flashcards
What is the turing machine ?
Theoretical model of computation
redefines real numbers, good for mathmeticians.
Not effiecient as a computer
What is management science ?
Using methods to help execute algorithms
Gantt charts etc
Who came up with the Lambda function ?
Church
What is the Church-Rosser theorem ?
Sub-expressions can be evaluated in any order enabling parallelism
How do we calculate power consumption of a CPU ?
P = C * V^2 * F
C = Capacitance
V = Voltage
F = Clock frequency
Why is parellel computing important ?
As the number of transistors increases, the clock speed is plateuing due to excess heat.
Parallel processing allows us to increase performance further than just using one processor
What are the parallel computer classifications ?
Instruction level parallelism
Single instruction, Multiple data (SIMD)
Multiple instruction, Multiple data (MIMD)
What is Instruction level parallelism ?
implements parallelisation at the hardware level.
What are some ILP architectures ?
Multi-stage pipeline, Eager execution, Out-of-Order execution
What is SIMD ?
Uses long instruction words to represent multiple data items at once (e.g. 64 bit for 4x 16bit)
What is a GPU ?
Origianlly designed for manipulating computer graphics and image processing, now used a more general parallel unit
CPU vs GPU ?
CPU optimised for low-latency computations (more complex), GPU optimised for data-parallel and high throughput computations (Bigger calculations)
What are GPUs made up of ?
Multiple Compute devices, made up of multiple compute units containing multpile processing elements. Shared registers and caches
What is a work group ?
A group of processing elements within a compute unit all executing the same instruction
What is VLIW ?
Very long instructions words
What are the advantages of multi core CPUs ?
memory sharing means that all cores see the same address space
cache coherency means some cache levels are shared
What is a NUMA architecture ?
Non Uniform Memory Access
Single address space shared by processors, but access times are different
used in supercomputers
Name some supercomputers
Blue gene - protien folding problems
El Captain - 1 million CPU cores + 10 million GPU cores
What is cluster computing ?
Groups of computers workign in sync
What is grid computing ?
hundreds of identical pcs acting as on, connected via Ethernet
What is cloud computing ?
Like grid but can be is many different locations connected via internet
HPC vs Cloud ?
HPC - simulations, maths
Cloud - data science
Name some neural processing units
Google tensor units
arduino 101
HiSilicon kirin 970
