Plain language, precise meaning

Performance glossary

The terms behind Windows tuning, gaming benchmarks and troubleshooting—without the marketing fog.

1% low
A percentile-oriented FPS summary representing the slower end of captured frames. Useful for consistency, but methodology varies by tool.
Commit charge
Virtual memory that Windows has promised to processes. The commit limit is backed mainly by RAM plus page files.
DPC / ISR latency
Time spent servicing deferred procedure calls and interrupts in kernel drivers. Large stalls can affect real-time audio and responsiveness.
Frame time
The time required to produce one frame, usually measured in milliseconds. Lower and more consistent is better.
Game Mode
A supported Windows feature that prioritizes the game experience and reduces disruptive background activity.
HAGS
Hardware-accelerated GPU scheduling. A Windows graphics option that shifts more scheduling work to compatible GPU hardware. Results vary.
HVCI / Memory integrity
A virtualization-based Windows security feature that protects kernel code integrity.
Jitter
Variation in network latency over time. A stable 30 ms can feel better than a connection oscillating between 15 and 90 ms.
Page file
Disk-backed storage Windows uses as part of virtual memory and for some crash dumps. Disabling it reduces the commit limit.
PresentMon
An open-source frame-presentation capture technology used by performance tools to analyze frame timing.
ReBAR / SAM
Resizable BAR / Smart Access Memory lets the CPU map a larger portion of GPU memory when supported by firmware, GPU, driver and game.
S.M.A.R.T.
Drive self-monitoring attributes that can expose temperature, wear, errors and other health indicators.
Shader compilation
Translation of shader code into hardware-specific instructions. First-use compilation can produce stutter.
Standby memory
Cached data in RAM that Windows can reclaim when applications need it. It is not the same as unavailable memory.
Thermal throttling
A protective reduction in clock or power when temperature limits are reached.
TRIM / retrim
A command that tells an SSD which blocks are no longer in use so internal management can work efficiently.
VBS
Virtualization-based security, which uses the Windows hypervisor to isolate protected security operations.
VRAM
Graphics memory used for textures, render targets and other GPU resources. Exceeding practical budget can cause stutter.
VRR
Variable refresh rate lets a display synchronize refresh timing to delivered frames within its supported range.
WHEA
Windows Hardware Error Architecture, used to report hardware and firmware errors such as corrected CPU or memory events.