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Questions tagged [processors]

Relates to issues dealing with multiple processors. This tag is vague so please accompany it with more specific tags.

69 questions
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What is the difference between a 32-bit and 64-bit processor?

I have been trying to read up on 32-bit and 64-bit processors (http://en.wikipedia.org/wiki/32-bit_processing). My understanding is that a 32-bit processor (like x86) has registers 32-bits wide. I'm not sure what that means. So it has special…
user485498
37
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3 answers

Setting Ideal size of Thread Pool

What is the difference between- newSingleThreadExecutor vs newFixedThreadPool(20) in terms of Operating System and Programming point of view. Whenever I am running my program using newSingleThreadExecutor my program works very well and end to end…
arsenal
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Why does Windows switch processes between processors?

If a single threaded process is busy and uses 100% of a single core it seems like Windows is switching this process between the cores, because in Task Managers core overview all cores are equal used. Why does Windows do that? Isn't this destroying…
Verim
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availableProcessors() returns 1 for dualcore phones

I recently bought a Moto Atrix 2 mobile. When I tried to look at the processor specs in the phone, Runtime.getRuntime().availableProcessors() returned 1. /proc/cpuinfo too had information about just processor 0. Out of curiosity I checked the same…
M10TheMist
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1 answer

Do processors actually calculate multiplication by a zero or one? Why?

The Short Version In the following line: aData[i] = aData[i] + ( aOn * sin( i ) ); If aOn is 0 or 1, does the processor actually perform the multiplication, or does it conditionally work out the result (0 for 0, other-value for 1)? The Long…
Izhaki
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4 answers

Count Processors using C++ under Windows

Using unmanaged C++ on a Windows platform, is there a simple way to detect the number of processor cores my host machine has?
Paul Mitchell
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MPI Number of processors?

Following is my code in MPI, which I run it over a core i7 CPU (quad core), but the problem is it shows me that it's running under 1 processor CPU, which has to be 4. int main(int argc, char *argv[]) { int rank, size; MPI_Init(&argc,…
Gabriel
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Will a multi-threaded application be actually faster than a single-threaded application?

All is entirely theoretical, the question just came to mind and I wasn't entirely sure whats the answer: Assume you have an application that calculates 4 independent calculations. (Totally independent, doesn't matter what order you do them and you…
AlexD
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Java: Cores available to the JVM?

In Java there's the method Runtime.getRuntime().availableProcessors() which has the following Javadoc: Returns the number of processors available to the Java virtual machine. This value may change during a particular invocation of the virtual…
Jonas
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Connecting NiFi to ElasticSearch

I'm trying to solve one task and will appreciate any help - links to documentation, or links to forums, or other FAQs besides https://cwiki.apache.org/confluence/display/NIFI/FAQs, or any meaningful answer in this post =) . So, I have the following…
Anna Vergeles
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2 answers

is multi-threading dependent on the architecture of the machine?

I have been reading lately about system architecture and the topic of multi-threading has not been covered in detail with latest improvements in technology. I did my part of search, but could not find answers for the following: The questions have…
brain storm
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Windows environment variable NUMBER_OF_PROCESSORS shows different value within JVM and outside

On our Windows Server 2019, we have 36 cores and 72 logical processors, as seen in Task Manager CPU performance window. And, also, if from command prompt, if I run the command. echo %NUMBER_OF_PROCESSORS% It tells me 72. However, from within Java…
Dr. Debasish Jana
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How does the JVM work considering computer organization?

I thought I've always understood why Java was portable, until I took Computer Organization. This is my interpretation of a C program from start to finish: C program --> compiler --> assembly --> machine code --> ISA --> micro architecture (how the…
jinan
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Wrong mpi number of processors

Sorry, I'm sure making a silly mistake, but did not work out. I'm compiling a simple mpi hello world: #include #include int main (argc, argv) int argc; char *argv[]; { int rank, size; MPI_Init (&argc, &argv); …
John Fadria
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Should I worry about Big Endianness or is it only a trivial aspect?

Are there many computers which use Big Endian? I just tested on 5 different computers, each purchased in different years, and different models. Each use Little Endian. Is Big Endian still used now days or was it for older processors such as the…
Johnathan
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