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I just created it in early December, 2018


Multiple BOINC Clients on one (Windows) machine

I copied this information from xtremesystems some time ago.  Hopefully someone else can benefit

from it besides me.

Step 1.
BOINC needs a place to keep its config for each running instance. So make a new BOINC directory for this new instance. The default BOINC data directory is C:\ProgramData\BOINC so something similar to that would be good. (EG: C:\ProgramData\BOINC_2). PS: the C:\ProgramData folder is a hidden folder. You can do this now by opening a cmd prompt and just copy/pasta this into it:


mkdir c:\programdata\BOINC2

Step 2.
Next is to get the new client's data directory populated with the configs.
Hit Win+R and type CMD, a command prompt opens. Type (with the quotes, adjust your path if needed), or just copy/paste if your path's are default like mine:

"C:\Program Files"\BOINC\boinc.exe --allow_multiple_clients -dir c:\programdata\BOINC2

Once it loads up you'll see a bunch of stuff happening, the data dir is now ready so hit Control C to break out.

Step 3.
Change the password in the gui_rpc_auth.cfg file which now resides in the new BOINC data directory.

notepad c:\ProgramData\BOINC2\gui_rpc_auth.cfg

erase the temporary password, type in something easy to remember -> save the file.

Step 4.
Now to load up the second BOINC client and have it listen for a connection. From a command prompt open the new BOIC client and let it run. If you close it (by typing CTRL C) the client will shut down. Here is the command using the paths from above:


"C:\Program Files"\BOINC\boinc.exe --allow_multiple_clients -dir c:\programdata\BOINC2 -gui_rpc_port 9999

The port above ^ can be whatever you want, but I recommend 9999 because it works for me!

Step 5. (skip this step if you would rather use a .bat file to launch your second BOINC client)

Connecting to the new client with BOINC Manager.
Just open your normal BOINC manager. I just double clicked mine in the task bar. Next, go to Advanced -> Launch another BOINC Manager. In the box for host name type

and in the password box, type in the password you chose in step 3.

You can follow step 5 above, or instead use the following code to create a bat file to launch our second BOINC client.

Copy and paste everything in yellow into a text file and save it as (for example) boinc-client2.bat.  Replace each instance of "9999" with whatever password you chose above.

Dim WshShell, oExec, boinc2_cmd, boincmgr2_cmd, cmd_a, cmd_b, cmd_1, cmd_2
Set WshShell = CreateObject("WScript.Shell")

cmd_a = "C:\Program Files\BOINC\boinc.exe"
cmd_b = "--allow_multiple_clients --dir C:\programdata\BOINC2 --gui_rpc_port 9999"
boinc2_cmd = cmd_a & " " & cmd_b

cmd_1 = "C:\Program Files\BOINC\boincmgr.exe"
cmd_2 = "/a /s /n /g 9999 /p 9999 /m"
boincmgr2_cmd =  cmd_1 & " " & cmd_2

'Execute boinc
Set oExec = WshShell.Exec(boinc2_cmd)

'Wait to start in ms
WScript.sleep 5000

'Execute boincmgr
Set oExec = WshShell.Exec(boincmgr2_cmd)

After all that work you should now have multiple BOINC clients running on one machine, and be able to manage them with separate GUI's. You can add a project to the new BOINC just the same way you normally would, and throttle CPU/GPU settings accordingly. Once again, I hope this helps you guys and saves some time. It took me a while to figure this all out and get it working.

The end result is being able to run exactly what you want, and on the cores you want.

  • SkyHighWeFly

Not for sure what I'm going to add to this website, I guess I'll figure something out eventually.

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