ATLAS@Home is a research project that uses volunteer computing to run simulations of the ATLAS experiment at CERN. You can participate by downloading and running a free program on your computer.

ATLAS is a particle physics experiment taking place at the Large Hadron Collider at CERN, that searches for new particles and processes using head-on collisions of protons of extraordinary high energy. Petabytes of data were recorded, processed and analyzed during the first three years of data taking, leading to up to 300 publications covering all the aspects of the Standard Model of particle physics, including the discovery of the Higgs boson in 2012.

Large scale simulation campaigns are a key ingredient for physicists, who permanently compare their data with both "known" physics and "new" phenomena predicted by alternative models of the universe, particles and interactions. This simulation runs on the WLCG Computing Grid and at any one point there are around 150,000 tasks running. You can help us run even more simulation by using your computer's idle time to run these same tasks.

On this page you can see ATLAS monitoring of the tasks running on ATLAS@Home, as well as how ATLAS@Home ("BOINC") compares to the other sites on the WLCG.

The program you will download runs simulation software inside a virtual machine hosted by your computer. The virtual machine image is ~500MB but is only downloaded once. Each workunit downloads a small set of input data and runs for approx 1 to 2 hours depending on the computer's processor speed.

Please consult or post to the message boards to learn more about the work currently available or in case of problems.

The Physics of ATLAS@Home

No knowledge of particle physics is required, but for those interested in the physics processes simulated in ATLAS@Home as well as the ATLAS experiment itself visit our public page.

ATLAS@Home tasks progress, for each task (number of jobs done/total number of jobs):

  • Task mc15_13TeV BFilter_fac025.simul (9079481): 13722/14999
  • Task mc15_13TeV BFilter_ckkw30.simul (9079468): 14056/14998
  • Task mc15_13TeV BFilter_ckkw15.simul (9079281): 14110/15000
  • Task mc15_13TeV BFilter_fac4.simul (9079039): 11238/12000
  • Task mc15_13TeV BFilter_renorm025.simul (8926742): 14927/14998
  • Task mc15_13TeV BFilter_renorm4.simul (8915503): 11951/12000
  • Task mc15_13TeV BFilter_qsf025.simul (8915159): 11970/12000
  • Task mc15_13TeV BFilter_qsf4.simul (8911835): 14953/15000
  • Task mc15_13TeV 100_165.simul (8559613): 44920/80000
  • Task mc15_13TeV 100_165.simul (8559597): 78505/80000
  • Task mc15_13TeV 100_165.simul (8559575): 79345/80000
  • Task mc15_13TeV 100_165.simul (8559551): 79905/80000
  • Task mc15_13TeV 100_165.simul (8455077): 79916/80000
  • Task mc15_13TeV 100_165.simul (8455038): 79933/80000
  • Task mc15_13TeV 100_165.simul (8455004): 73887/80000

Join ATLAS@Home

  • Read our rules and policies
  • This project uses BOINC. If you're already running BOINC, select Add Project. If not, download BOINC.
  • This project also requires VirtualBox to be installed.
    • Windows: VirtualBox is included in Windows distributions of Boinc and so does not have to be installed separately.
    • Mac and Linux: VirtualBox must be installed separately
    • VirtualBox 5.0.x is the recommended version, 5.1 is known to cause problems so do not use this version.
  • After choosing Add Project in Boinc Manager, choose ATLAS@home from the list of projects
  • Then either enter details for to set up a new account, or if you have previously registered enter the existing account details.
    • A reasonably powerful modern 64-bit computer with at least 4GB of memory is required to run ATLAS@Home. Enabling 64-bit virtualisation may require some changes in BIOS settings.
    • In Boinc Manger set the % of processors used to be at most 50%, otherwise your computer may run out of memory.
    • The work units may use a lot of network bandwidth, so a slow internet connection may reduce work unit efficiency
    • The work units contact servers at CERN and outside CERN. If you are behind a firewall you will need to open access to these servers. Please contact us for details.
  • If you're running a command-line version of BOINC, create an account first.
  • If you have any problems, get help here.

User of the day

Profile AL ADIM
BOINC@Poland 4 ever!!!


New multi-core application version 1.03
A new version of the multi-core app was released this morning which fixes the issue with the bootstrap script only setting up one core for each WU. It is recommended to abort older tasks using v1.01 if you want to take advantage of the fully working multi-core version. 18 Jul 2016, 9:45:05 UTC · Comment

How can the BOINC client allocate customized CPU/Memory resources to specific applications
Some of the users might only want to give a certain ratio of their CPU/Memory to a specific application. Take the ATLAS@home Multiple core application ATLAS_MCORE for example, if you want to this app to use less than the CPU/Memory that you allow the BOINC client to use, you can do it through creating a configuration file app_config.xml in your project directory:

You can limit the MultiCore-App by using an app_config.xml.

Below is an example to limit ATLAS_MCORE to use only 4 Cores:

<app_config> <app_version> <app_name>ATLAS_MCORE</app_name> <avg_ncpus>4.000000</avg_ncpus> <plan_class>vbox_64_mt_mcore</plan_class> <cmdline>--memory_size_mb 5300</cmdline> </app_version> </app_config>

You should change these two lines to your needs:

<avg_ncpus>4.000000</avg_ncpus> <cmdline>--memory_size_mb 5300</cmdline>

Memory usage calculated by the ATLAS_MCORE app is by this formula:

memory = 1300 + (1000* NumerOfCores)

so it is 5300MB for 4 cores.

Thanks to Yeti for giving this recipe. 14 Jul 2016, 8:42:51 UTC · Comment

ATLAS@home releases a beta application for the multi core jobs
We have released a beta application named "ATLAS_MCORE" for the ATLAS multi-core jobs.

If you are interested in testing it on your machine, you need to allow test task in your project preference to receive jobs from this new application.

This can be enabled by login to your account on the atlasathome webpage, then click on "Your account", then click on "ATLAS@Home preferences", then check the box next to "Run test applications".

The multi-core version will check the BOINC client for both the available CPU cores(the number of CPU cores the client is configured to give to BOINC to use) and available memory size(the number of memory size the client is configured to give to BOINC to use) to decide how many cores will be allocated to one virtual machine which runs the ATLAS job.

For the ATLAS multi-core job, the relation between memory size and number of CPU cores is defined in this formula:


For example, a 1 core job requires 2300 MB memory, and a 2 core job requires 3300 MB memory.

The number of CPU cores which will be allocated to the virtual machine is also calculated according to this formula.
The minimum number between Number_of_CPU_cores and the available CPU cores from the client is used to allocate to the virtual machine.

Currently, this test app can utilize from 2 to 8 cores of the client depending on the available CPU cores and memory size from the client.

By using multi-core jobs, we expect the runtime of jobs is close to runtime_of_single_core_job/number_of_cores, and it can significantly saves the usage of memory for clients which offers multi-cores to BOINC.
11 Jul 2016, 15:51:59 UTC · Comment

Disk space limit decreased to 4GB
Hi all,

To make more effective use of volunteers running ramdisks we have reduced the disk space limit from 6.5GB to 4GB. See thread here

We see that most tasks use at most 2.2GB so this should be safe, but please notify us of any problems related to this change.[/url]
24 Jun 2016, 7:30:30 UTC · Comment

WU running out shortly - more on Monday 6th
Hi all, just a heads up that we will likely run out of WU in the next few hours. We should get some more back in the system on Monday. 4 Jun 2016, 18:23:12 UTC · Comment

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