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In the single processor and SMP systems with few CPUs, one of our goals as programmers should be to stay out of the way of the compiler. Often constructs used to improve performance on a particular architecture limit our ability to achieve performance on another architecture. Further, these “brilliant” (read obtuse) hand optimizations often confuse a compiler, limiting its ability to automatically transform our code to take advantage of the particular strengths of the computer architecture.

As programmers, it is important to know how the compiler works so we can know when to help it out and when to leave it alone. We also must be aware that as compilers improve (never as much as salespeople claim) it’s best to leave more and more to the compiler.

As we move up the hierarchy of high performance computers, we need to learn new techniques to map our programs onto these architectures, including language extensions, library calls, and compiler directives. As we use these features, our programs become less portable. Also, using these higher-level constructs, we must not make modifications that result in poor performance on the individual RISC microprocessors that often make up the parallel processing system.

Measuring performance

When a computer is being purchased for computationally intensive applications, it is important to determine how well the system will actually perform this function. One way to choose among a set of competing systems is to have each vendor loan you a system for a period of time to test your applications. At the end of the evaluation period, you could send back the systems that did not make the grade and pay for your favorite system. Unfortunately, most vendors won’t lend you a system for such an extended period of time unless there is some assurance you will eventually purchase the system.

More often we evaluate the system’s potential performance using benchmarks . There are industry benchmarks and your own locally developed benchmarks. Both types of benchmarks require some careful thought and planning for them to be an effective tool in determining the best system for your application.

The next step

Quite aside from economics, computer performance is a fascinating and challenging subject. Computer architecture is interesting in its own right and a topic that any computer professional should be comfortable with. Getting the last bit of per- formance out of an important application can be a stimulating exercise, in addition to an economic necessity. There are probably a few people who simply enjoy matching wits with a clever computer architecture.

What do you need to get into the game?

  • A basic understanding of modern computer architecture. You don’t need an advanced degree in computer engineering, but you do need to understand the basic terminology.
  • A basic understanding of benchmarking, or performance measurement, so you can quantify your own successes and failures and use that information to improve the performance of your application.

This book is intended to be an easily understood introduction and overview of high performance computing. It is an interesting field, and one that will become more important as we make even greater demands on our most common personal computers. In the high performance computer field, there is always a tradeoff between the single CPU performance and the performance of a multiple processor system. Multiple processor systems are generally more expensive and difficult to program (unless you have this book).

Some people claim we eventually will have single CPUs so fast we won’t need to understand any type of advanced architectures that require some skill to program.

So far in this field of computing, even as performance of a single inexpensive microprocessor has increased over a thousandfold, there seems to be no less interest in lashing a thousand of these processors together to get a millionfold increase in power. The cheaper the building blocks of high performance computing become, the greater the benefit for using many processors. If at some point in the future, we have a single processor that is faster than any of the 512-processor scalable systems of today, think how much we could do when we connect 512 of those new processors together in a single system.

That’s what this book is all about. If you’re interested, read on.

Questions & Answers

what is Nano technology ?
Bob Reply
write examples of Nano molecule?
The nanotechnology is as new science, to scale nanometric
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
for teaching engĺish at school how nano technology help us
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, High performance computing. OpenStax CNX. Aug 25, 2010 Download for free at http://cnx.org/content/col11136/1.5
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