multicore

问题 I have read that R uses only a single CPU. How can I let R use all the available cores to run statistical algorithms? 回答1: Yes, for starters, see the High Performance Computing Task View on CRAN. This lists details of packages that can be used in support of parallel computing on a single machine. From R version 2.14.0, there is inbuilt support for parallel computing via the parallel package , which includes slightly modified versions of the existing snow and multicore packages. The parallel

问题 I have read that R uses only a single CPU. How can I let R use all the available cores to run statistical algorithms? 回答1: Yes, for starters, see the High Performance Computing Task View on CRAN. This lists details of packages that can be used in support of parallel computing on a single machine. From R version 2.14.0, there is inbuilt support for parallel computing via the parallel package , which includes slightly modified versions of the existing snow and multicore packages. The parallel

问题 I have run simple parallel algorithm drawing the mandelbrot set to test parallel computations on a Nexus 7 (Tegra 3, 4+1 cores). After running several times I get 1.5 seconds for serial and 1.0 for parallel, but parallel and serial come really close to each other at 1.3 seconds. The square is 700x700 pixels, and the mandelbrot code I use is from http://rosettacode.org/wiki/Mandelbrot_set#Java The parallel implementation runs two halves of mandelbrot like this public void mandelbrotParallel()

问题 This question already has answers here : Can Python's unittest test in parallel, like nose can? (7 answers) Closed 3 years ago . I'm using python unittest in order to test some other external application but it takes too much time to run the test one by one. I would like to know how can I speedup this process by using the power of multi-cores. Can I tweak unittest to execute tests in parallel? How? This question is not able python GIL limitation because in fact not the python code takes time

问题 I am playing around with haskell, starting with simple plotting programs to wet my feet. I need a library that will let me save a 2D array/vector to an image file. I don't want to write a list of colors. I want to use containers that are meant for array/vector like computations and can be (well, almost ) automagically parallelized. EDIT Ability to store color images is a must. 回答1: I'd start with PGM library. This is a very simple uncompressed graymap format. Almost no additinal dependencies.

问题 One of the new performance enhanchements for .NET 4.5 is the introduction of the 'MultiCode JIT'. See here for more details. I have tried this, but it seems to have no effect on my application. The reason why I am interested is that my app (IronScheme) takes a good long time to startup if not NGEN'd, which implies a fair amount of JIT'ng is involved at startup. (1.4 sec vs 0.1 sec when NGEN'd). I have followed the instructions on how to enable this, and I can see a 'small' (4-12KB) is created

问题 There are three thread models that are used in thread scheduling implementations usually done by OS Kernels. One of them is the hybrid ( M:N ) model in which some N application threads are mapped to M kernel threads so that they can use up to M processors. There are pros and cons to this model. One of the advantages is that the languages that are based on this model will introduce a language level scheduler implementation that is responsible for management and scheduling the application-level

问题 So, I'm toying around with Stackless Python and a question popped up in my head, maybe this is "assumed" or "common" knowledge, but I couldn't find it actually written anywhere on the stackless site. Does Stackless Python take advantage of multicore CPUs? In normal Python you have the GIL being constantly present and to make (true) use of multiple cores you need to use several processes, is this true for Stackless also? 回答1: Stackless python does not make use of any kind of multi-core

问题 Closed. This question is off-topic. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 11 months ago . The CPU architecture landscape has changed, multiple cores is a trend that will change how we have to develop software. I've done multi-threaded development in C, C++ and Java, I've done multi-process development using various IPC mechanisms. Traditional approaches of using threads doesn't seem to make it easy

问题 If I write a multi-threaded java application, will the JVM take care of utilizing all available cores? Do I have to do some work? 回答1: Unless you use a JVM that has so-called "green" threads (which is very few these days), Java threads are run by OS threads, so multiple threads get run on different cores by default. 回答2: To follow up, I see 100% usage on both cores when I run this code on my dual core. If I bring the number of threads from two to one, one core goes to 100% and another about 4