Daniel Cox wrote:This thread says “Java can't scale to multiple processors in a world of 8 core desktops and quad core cell phones”
Daniel Cox wrote:Is the main difference that a quad core computer is simply more responsive than a single core computer when dealing with large computation-intensive applications?
Daniel Cox wrote:Also, is there any real difference between programming an application for a single core computer versus programming an application for a quad core computer?
Daniel Cox wrote:This thread says “Java can't scale to multiple processors in a world of 8 core desktops and quad core cell phones”
Daniel Cox wrote:With one arm, you can execute multiple tasks and multiple threads at the same time but with four arms you can do the same with increased responsiveness?
"Leadership is nature's way of removing morons from the productive flow" - Dogbert
Articles by Winston can be found here
From the beginning, Java supported concurrency in the form of low-level threads management, locks, synchronization, and APIs for concurrency.
Since 5.0, Java also supports high-level concurrency APIs in its java.util.concurrent package. In this chapter, we’ll focus on these APIs for concurrent programming. These high-level APIs exploit today’s multi-core hardware, in which a single processor has multiple cores. These APIs are also useful for exploiting concurrency in machines that support multiple processors.
Daniel Cox wrote:What's the difference between programming a multi-threaded pre-Java 5 application and a multi-threaded post-Java 5 application? The quote from the OCP Certification Guide seems to suggest that a multi-threaded pre-Java 5 application cannot fully exploit concurrency in today’s multi-core hardware.
"Leadership is nature's way of removing morons from the productive flow" - Dogbert
Articles by Winston can be found here
Daniel Cox wrote:What's the difference between programming a multi-threaded pre-Java 5 application and a multi-threaded post-Java 5 application?
Daniel Cox wrote:The quote from the OCP Certification Guide seems to suggest that a multi-threaded pre-Java 5 application cannot fully exploit concurrency in today’s multi-core hardware.
Java’s thread- and lock-based concurrency is very low-level, and often hard to work with. To cope with this, a set of concurrency libraries, known as java.util.concurrent, was introduced in Java 5. This provided a set of tools for writing concurrent code that many programmers find easier to use than the classic block-structured concurrency primitives.
If you have existing multi-threaded code that is still based on the older (pre-Java 5) approaches, you should refactor it to use java.util.concurrent. In our experience, your code will be improved if you make a conscious effort to port it to the newer APIs—the greater clarity and reliability will be well worth the effort expended to migrate in almost all cases.
The future of performance is intimately tied to concurrency—one of the main ways that a system can be made more performant overall is by having more cores. That way, even if one core is waiting for data, the other cores may still be able to progress.
Daniel Cox wrote:Chapter 6 says:
The future of performance is intimately tied to concurrency—one of the main ways that a system can be made more performant overall is by having more cores. That way, even if one core is waiting for data, the other cores may still be able to progress.
"Leadership is nature's way of removing morons from the productive flow" - Dogbert
Articles by Winston can be found here
Winston Gutkowski wrote:Not sure I agree with that.
Daniel Cox wrote:If not better performance, why do you think that processors these days have multiple cores?
"Leadership is nature's way of removing morons from the productive flow" - Dogbert
Articles by Winston can be found here
Daniel Cox wrote:Chapter 6 says:
The future of performance is intimately tied to concurrency—one of the main ways that a system can be made more performant overall is by having more cores. That way, even if one core is waiting for data, the other cores may still be able to progress.
Winston Gutkowski wrote:
Scott Shipp wrote:In My Humble Opinion...
Gets a cow from me.
Winston
As the rate of clock speed improvements slowed, increased use of parallel computing in the form of multi-core processors has been pursued to improve overall processing performance.
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