Priorities

CPU Priority Classes

• Menu path: ‘Options / CPU / CPU Priorities …’

Priority classes, sometimes referred to as ‘CPU Priorities’ in Process Lasso, are available to keep applications running at specific priorities.

It is generally best to focus on lowering priorities of background and unimportant processes, rather than raising the priorities of important ones. This is simply due to the design of Windows. The ProBalance algorithm applies these adjustments to CPU heavy background processes dynamically.

Priority classes available in Windows are:

• Real-Time
• High
• Above Normal
• Normal
• Below Normal
• Idle

Normally setting the priority class is sufficient, but I/O priorities and memory priorities can also be set using their corresponding menu items and dialogs.

The menu item “Windows dynamic thread priority boosts enabled” can be checked to disable that native Windows feature. This is the same setting reflected in the “Boost” context menu item.

GPU Priority Classes

• Menu path: ‘Options / GPU / GPU Priorities …’

With AI workloads increasingly competing for GPU resources, we felt it important to add GPU priority support to Process Lasso. Now users can ensure that their most important GPU workloads, such as gameplay, are prioritized.

Available GPU priority classes are the same as CPU priority classes:

• Real-time
• High
• Above Normal
• Normal
• Below Normal
• Idle

A new GPU priority column is shown in the process lists that indicates the GPU priority class.

Users can set GPU priority rules via the process context menu or by menu item “Options / GPU / GPU Priorities…”.

Unfortunately, GPU priority classes are not inherited by child processes and “Enforce by Registry” (IFEO) methods are not supported. This means that processes protected by anti-cheat systems won’t be able to have their GPU priorities set. In these cases, we instead recommend focusing on ensuring other processes with GPU workloads are set to below normal or idle priorities.

I/O Priorities

I/O priorities provide a hint to the OS about the relative importance of I/O for a process. However, no guarantee is made about prioritization over other I/O, or specific QoS parameters.

• High
• Normal
• Low
• Very Low

Memory Priorities

Memory priorities provides a hint to the OS about the relative importance of memory pages when they are being paged out.

… [one] should lower the default memory priority of threads that perform background operations or access files and data that are not expected to be accessed again soon. For example, a file indexing application might set a lower default priority for the process that performs the indexing task.

Memory priority helps to determine how long pages remain in the working set of a process before they are trimmed. A process’s memory priority determines the default priority of the physical pages that are added to the process working set by the threads of that process. When the memory manager trims the working set, it trims lower priority pages before higher priority pages. This improves overall system performance because higher priority pages are less likely to be trimmed from the working set and then trigger a page fault when they are accessed again.

SetProcessInformation function (processthreadsapi.h) – Win32 apps | Microsoft Learn

• Normal
• Below Normal
• Medium
• Low
• Very Low

Enforce By Windows Registry

• Menu path: ‘Options / General / View Priorities Saved to Registry …’

This option uses the Windows Image File Execution Options feature to save the priority to the registry so that every time that process is launched it will start with the chosen priority. This has the advantage of circumventing anti-cheat systems that may be protecting a process from modification. It has the disadvantage of persisting in the registry, so these settings may go unnoticed and forgotten about if not managed with a tool like Process Lasso.

This feature supports priority classes, I/O priorities and memory priorities. CPU affinities and other rule types are not supported.

Use of this method is benign so is not known to cause any alerts within anti-cheat systems. The priority restriction enforced by anti-cheat systems is more a side-effect of the process protection, rather than one of the aims.

Priorities saved to the registry for review and cleanup

Boost

• Menu path: ‘Options / CPU / Dynamic Thread Priority Boosts …’

Dynamic thread priority boosting is a native feature of Windows that temporarily boosts the priority of threads when they wake to resume work. It defaults to ON for new processes and should normally remain ON.

When dynamic thread priority boosts are disabled for a process, the priority class name will have a hyphen appended to it. You can toggle boosts on or off using the “Boost” context menu or “Options / CPU / Dynamic Thread Priority Boosts…”.

Dynamic Thread Priority Boost disabled is indicated by hyphen.