# 0.11 Multicore programming

 Page 1 / 1
The creation of this content was supported in some part by NSF grant 0538934.

If you have written parallel programs in G and have a multicore computer, CONGRATULATIONS!!! You have been successfully developing interactive parallel programs that execute in multicore PC processors.

The following sections discuss some multicore programming techniques to improve the performance of G programs.

## Data parallelism

Matrix multiplication is a compute intensive operation that can leverage data parallelism. [link] shows a G program with 8 sequential frames to demonstrate the performance improvement via data parallelism.

The Create Matrix function generates a square matrix based of size indicated by Size containing random numbers between 0 and 1. The Create Matrix function is shown in [link] .

The Split Matrix function determines the number of rows in the matrix and shifts right the resulting number of rows by one (integer divide by 2). This value is used to split the input matrix into the top half and bottom half matrices. The Split Matrix function is shown in [link] .

Sequence Frame Operation Description
First Frame Generates two square matrices initialized with random numbers
Second Frame Records start time for single core matrix multiply
Third Frame Performs single core matrix multiply
Fourth Frame Records stop time of single core matrix multiply
Fifth Frame Splits the matrix into top and bottom matrices
Sixth Frame Records start time for multicore matrix multiply
Seventh Frame Performs multicore matrix multiply
Eighth Frame Records stop time of multicore matrix multiply

The rest of the calculations determine the execution time in milliseconds of the single core and multicore matrix multiply operations and the performance improvement of using data parallelism in a multicore computer.

The program was executed in a dual core 1.83 GHz laptop. The results are shown in [link] . By leveraging data parallelism, the same operation has nearly a 2x performance improvement. Similar performance benefits can be obtained with higher multicore processors

A variety of applications require tasks to be programmed sequentially and continually iterate on these tasks. Most notably are telecommunications applications require simultaneous transmit and receive. In the following example, a simple telecommunications example illustrates how these sequential tasks can be pipelined to leverage multicore environments.

Consider the following simple modulation - demodulation example where a noisy signal is modulated transmitted and demodulated. A typical diagram is shown in [link] .

Adding a shift register to the loop allows tasks to be pipelined and be executed in parallel in separate cores should they be available. Task pipelining is shown in [link] .

The program below times the sequential task and the pipelined tasks to establish its performance improvement when executed in multicore computers.

[link] shows the results of running the above G program in a dual core 1.8 GHz laptop. Pipelining shows nearly 2x performance improvement.

## Pipelining using feedback nodes

Feedback Nodes provide a storage mechanism between loop iterations. They are programmatically identical to the Shift Registers . Feedback Nodes consist of an Initializer Terminal and the Feedback Node itself (see [link] ).

To add a Feedback Node , right click on the Block Diagram window and select Feedback Node from the Functions>>Programming>>Structures pop-up menu. The direction of the Feedback Node can be changed by right clicking on the node and selecting Change Direction .

The diagram shown in [link] is programmatically identical to the diagram in [link] .

Similarly, the diagram in [link] is programmatically identical to that in [link] .

are nano particles real
yeah
Joseph
Hello, if I study Physics teacher in bachelor, can I study Nanotechnology in master?
no can't
Lohitha
where we get a research paper on Nano chemistry....?
nanopartical of organic/inorganic / physical chemistry , pdf / thesis / review
Ali
what are the products of Nano chemistry?
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
da
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Bhagvanji
hey
Giriraj
Preparation and Applications of Nanomaterial for Drug Delivery
revolt
da
Application of nanotechnology in medicine
has a lot of application modern world
Kamaluddeen
yes
narayan
what is variations in raman spectra for nanomaterials
ya I also want to know the raman spectra
Bhagvanji
I only see partial conversation and what's the question here!
what about nanotechnology for water purification
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
nanocopper obvius
Alexandre
what is the stm
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
what is Nano technology ?
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
what king of growth are you checking .?
Renato
how did you get the value of 2000N.What calculations are needed to arrive at it
Privacy Information Security Software Version 1.1a
Good
Got questions? Join the online conversation and get instant answers!