What is the difference between linq and plinq

Gunnar Peipman is ASP. This source code was a great example. So simple and easy to understand. I commented it out, it built without errors and gave me the same results. The first thing i find out this code which Matt talking about.

Your email address will not be published. Notify me when new comments are added. Skip to content. Demo PrimeNumberDemo. If you want to see how LINQ works then use this code. Download sample solution Liked this post? Empower your friends by sharing it! If the value is , then the point was not within the radius of any of the targets, else the index of the target nearest to the point is returned.

The standard LINQ will execute on a one processor core. To make use of more cores, simply insert AsParallel before the Where method. Let's now look at the code that will communicate with the GPU. This is implemented in the Track class. The constructor takes care of Cudafying. Here we wish to Cudafy two types: Track and TrackPoint. The key to efficient use of a GPU for general purpose programming is to minimize the amount of data that needs to transfer between the host and the GPU device.

Here we do this by first loading the track. We can then run multiple queries without having to reload the track. Since by default we're going to operate on 10,, GPS points which represent ,, bytes two System. Double and one System. Int64 fields per GPS point: longitude, latitude, and timestamp , this is important.

The track is uploaded as an array of points. Per corresponding point, we will fill in either if the point is not within the radius and date range of any of the targets, or the index of the target if it is within:.

The method we will call from our application is SelectPoints. GPUs have multiple forms of memory. However, on the GPU, use of different memory types is advisable as it can have a major impact on performance. The biggest and also slowest memory is global.

That's where we've stored our track. Another memory is constant memory. It can only be written to by the host. For the GPU, it is read-only and very fast. We will use it for storing our targets. Keep in mind that the amount of constant memory is very limited think KBytes, not MBytes and cannot be freed. Device functions are said to be launched. The Launch method of the GPU device takes the following parameters:. This number can be quite high but if the GPU function takes more than 0. With the same query on a single-core, or with processor affinity meaning only one core is available e.

There could still be a gain if there's blocking on resources, but the benefit depends on the machine then. Third, if there's any shared resource maybe an collection results are being output to is used in a non-threadsafe way, it can go pretty badly wrong with incorrect results, crashes, etc.

Fourth, if there's a shared resource being used in a threadsafe way, and that threadsafety comes from locking, there could be enough contention to become a bottleneck that undoes all the benefits from the parallelisation.

Fifth, if you've a four-core machine working on more or less the same algorithm on four different threads perhaps in a client-server situation due to four clients, or on a desktop situation from a set of similar tasks higher in the process , then they're alreay making the best use of those cores. Splitting the work in the algorithm up so as to be handled across all four cores means you've moved from four threads using one core each to 16 threads fighting over four cores.

At best it'll be the same, and likely overheads will make it slightly worse. It can still be a major win in a lot of cases, but the above should make it clear that it won't always. My advice is to test your query. Test 1: Increasing the number of iterations in the query by increasing the number of objects in the collection. Although in a professional environment, I've never queried or even initialised a collection of 10 million objects in memory so this might be an unlikely scenario where PLINQ happens to be superior to LINQ.

I set the number of objects in the collection to always be 10 so the query involves a low number of iterations. For each test, I increased the work involved to process each iteration. Definition of increasing the work : Increasing the number of iterations to multiply the int by PLINQ was faster at querying the collection as the work was significantly increased when the number of iterations inside a work iteration was increased to 10 million and I concluded that PLINQ is superior to LINQ when a single iteration involves this amount of work.

See Test 2 code below. PLinq is the parallel version of Linq. Some queries can be executed on multiple threads and then PLinq gives a performance increase. So when to use PLinq is something you should decide on for each query and make sure the performance actually increases. MSDN has a lot of documentation on it. This increased performance brings high performance computing power onto the desktop.

Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Collectives on Stack Overflow. Learn more. Difference linq and plinq Ask Question. Asked 9 years, 11 months ago. Active 1 year, 9 months ago. Viewed 6k times. What is the difference between these two?