Bitsum Process Lasso 19.0.0.44

Process Lasso is Windows process automation and optimization software. From tuning algorithms like ProBalance to user-created rules and persistent settings such as CPU affinities and priority classes, Process Lasso enables full control over running applications!

Process Lasso v18 Main Window

Our famous ProBalance algorithm maintains system responsiveness during high CPU loads. This proprietary algorithm dynamically adjusts the priorities of running programs to keep problematic background processes in check. With ProBalance, no longer will single, or multiple, processes be able to bring your system to a virtual stall. Process Lasso will let you keep interacting with your computer, even when it is under a heavy CPU load. Try our CPUEater Demo to experience ProBalance for yourself.

Process Lasso also allows users to automate and tweak how applications are run through a number of unique and helpful functions. These include persistent priority classes, persistent CPU affinities, disallowed processes, per-process power profiles, a process watchdog for advanced rules, process instance count limits, multiple instance balancing and much more! These features give you the ability to control how programs utilize your computer’s resources based on automatically applied settings. With Process Lasso, you can decide exactly how you want your processes to run.

Process Lasso is the ultimate Windows CPU affinity changer. The CPU affinity specifies the set of CPU cores an application is able to execute on. With Process Lasso, you can control this with a persistent setting that applies every time the application is run, or change it dynamically while the application is running once a threshold is met. The CPU affinity is commonly changed to limit CPU use or improve performance.

Many additional functions such as power plan automation, a system responsiveness metric and process activity logging are also available.

For minimal resource use, all algorithms and process rules are enforced by a stand-alone background service called the Process Governor. The GUI is entirely optional.

Process Lasso Features

Persist CPU affinities, priorities and more
ProBalance priority optimization
Rules to act on processes when thresholds exceeded
Limit process CPU use
Automate power plan switching
Disable Hyper-Threading/SMT per-process
Balance multiple instances
Limit instances of applications
Disallow processes from running
Keep processes running (auto-restart)
Processor Group Extension
Keep PC awake
System responsiveness metric
C++ for maximum efficiency
Stand-alone background service applies rules
Much more …

19.0.0.94 – Nov 3, 2026

New LatencyTest tool
New Interrupt Affinity Policy tool
Minor fixes and enhancements

(9) GUI: New Interrupt Affinity Policy tool, IRQControl (Tools menu): choose which CPUs service each device’s interrupts, the interrupt priority and MSI mode; also available stand-alone
(13) GUI: New LatencyTest tool (Tools menu): measures DPC and ISR execution times per driver and per CPU, and thread wake latency; also available stand-alone
(33) All: Fix quoted command line switch values such as /startwithprofile=”My Profile” being ignored
(35) Governor: Assorted minor improvements
(37) Languages: Translation updates, fixes for clipped text, and message box buttons in the selected language
(45) Installer: Signed uninstaller
(53) Dark mode: Combo boxes, radio buttons, drop-downs and menu UAC shields are now dark
(55) GUI/Core: Better config reload when the config file is locked or unreachable
(61) GUI: New Tools menu: Bitsum programs, Windows tweaks and Windows utilities, including an online CPU/GPU/Memory Stress Test
(63) GUI: GPU Preference labels no longer swap High performance and Power saving on multi-GPU systems when Process Lasso itself has a Power saving GPU preference
(67) Installer: Various layout and functional improvements to the Startup Options dialogs
(69) Installer: Silent upgrades keep the selected language when the installing account has no saved installer language
(69) GUI: Performance Mode’s power plan setting is no longer replaced by a fallback plan after Select Power Profile is opened while the chosen plan is missing
(71) Installer: Silent installs and upgrades with /governor_start_type start the core engine the chosen way right away, and the Process Governor service survives the first restart after a fresh install
(75) All: CPU Limiter: New Scope setting to measure the combined CPU use of all matching processes, or of each user’s matching processes (e.g. on Remote Desktop and Azure Virtual Desktop hosts), and limit them together to a shared set of CPU cores. Rules now set the number of CPU cores to limit to; existing rules keep working as before. Older versions read a combined rule as a rule for each process
(77) GUI: If Process Lasso crashes while starting, for example while another program is hooking into it, it now restarts once by itself; crash dumps also record the exception for faster diagnosis
(85) GUI: Options > Log: the ProBalance begin and end log options are combined into one, Log ProBalance Events
(91) GUI: Improve behavior when /logfolder command line parameter is used