ISLC Guide: Stop Gaming Stutters with Standby List Cleaner

You are mid-match in a competitive game. Everything runs smoothly, then out of nowhere the game freezes for half a second, your framerate craters, and you die. No thermal throttle, no disk thrash — just random stuttering that appears after the system has been running for a while. If this sounds familiar, standby memory buildup is likely the culprit, and Intelligent Standby List Cleaner (ISLC) is the fix.

What Is Standby Memory?

Windows uses a memory management model called the Standby List. When an application closes or releases memory, Windows does not immediately zero that memory and return it to the free pool. Instead, it holds it in the standby list — a cache of recently-used memory pages that can be quickly reclaimed if the same (or another) application requests similar data.

This is usually efficient. The problem arises when the standby list grows large enough to crowd out your active application’s working set. When your game requests new memory and Windows needs to flush standby pages to free pool, it triggers a hard page fault — a delay that shows up as a frame time spike or outright stutter.

Reading Memory State in Resource Monitor

Press Win + R, type resmon, press Enter.
Click the Memory tab.
Look at the bar at the top — it shows In Use, Modified, Standby, and Free.

If Standby is several gigabytes and Free is near zero, you are in the danger zone.

What ISLC Does

ISLC is a lightweight utility by Wagnardsoft that monitors your standby list size and purges it when it crosses a threshold you define. It calls the NtSetSystemInformation API with SystemMemoryListCommand to flush standby pages back to the free pool — the same operation Windows would eventually do on its own, but proactively and on your schedule.

The key insight: clearing 4 GB of standby in a controlled moment between frames causes no visible stutter. Waiting for Windows to do it reactively mid-render causes a 300 ms freeze.

Downloading and Installing ISLC

ISLC is free and requires no installation in the traditional sense.

Visit Wagnard’s forum thread on guru3d.com (search “Intelligent Standby List Cleaner”).
Download the latest ZIP — as of early 2026, version 1.0.2.2 is current.
Extract to a permanent location: C:\Tools\ISLC\
Right-click ISLC.exe → Properties → Unblock (if Windows flagged it from the internet).

No installer, no registry entries from the setup process — just a portable executable.

Configuring ISLC

Launch ISLC.exe as Administrator (required to interact with the system memory API).

Key Settings

Setting	Recommended Value	Notes
Purge if standby list >	1024 MB	Lower for 16 GB systems; 2048 MB for 32 GB
Purge if free RAM <	1024 MB	Safety net; triggers purge regardless of standby size
Timer Resolution	0.5 ms	Sets system timer resolution while ISLC is running
Enable custom timer resolution	Checked	Pairs with timer resolution tuning
Start with Windows	Checked	Ensures ISLC runs before your first gaming session

The Polling Interval

ISLC checks memory state every 1000 ms by default. You can lower this to 500 ms for more aggressive monitoring, but 1000 ms is fine for gaming — the standby list does not fill in under a second.

Timer Resolution Integration

ISLC has a built-in timer resolution setter. If you are already using SetTimerResolution separately, disable ISLC’s timer resolution feature to avoid conflicts. If ISLC is your only timer tuning tool, enable it and set 0.5 ms here.

Starting ISLC Automatically at Boot

Because ISLC requires administrator privileges, a standard startup folder shortcut will not work — Windows will prompt for UAC elevation each time. Use Task Scheduler instead:

$action = New-ScheduledTaskAction `
    -Execute "C:\Tools\ISLC\ISLC.exe" `
    -Argument "/minimized"
$trigger = New-ScheduledTaskTrigger -AtLogOn
$settings = New-ScheduledTaskSettingsSet -ExecutionTimeLimit 0 -AllowStartIfOnBatteries $true
$principal = New-ScheduledTaskPrincipal `
    -UserId "$env:USERNAME" `
    -LogonType Interactive `
    -RunLevel Highest
Register-ScheduledTask -TaskName "ISLC_AutoStart" `
    -Action $action `
    -Trigger $trigger `
    -Settings $settings `
    -Principal $principal

The /minimized argument launches ISLC to the system tray rather than opening a window.

Verifying ISLC Is Working

Once ISLC is running, watch the Purge count field in its interface. It should tick up every time the standby list crossed your threshold. If you have been gaming for an hour and the count is 20–30, ISLC has been doing its job — each of those purges was a potential stutter that you never felt.

You can also cross-reference with Windows Event Viewer:

Get-WinEvent -FilterHashtable @{LogName='System'; Level=2} | `
    Where-Object {$_.Message -like "*memory*"} | `
    Select-Object TimeCreated, Message | `
    Format-List

If you previously had memory pressure events and they disappear after running ISLC, you have confirmed the fix.

ISLC vs. Windows Memory Compression

Windows 11 has a Memory Compression feature that compresses standby pages instead of evicting them. This is beneficial on systems with limited RAM (8 GB) but can add CPU overhead on systems with 32 GB or more. You can check compression status:

Get-MMAgent

Look for MemoryCompression : True. On high-RAM systems, some users disable compression and rely on ISLC instead:

# Disable memory compression (optional, test carefully)
Disable-MMAgent -MemoryCompression

Only disable compression if you have 32 GB or more and find ISLC alone handles your use case. Re-enable if you notice increased page file usage.

ISLC for Specific Game Types

Not every game benefits equally from ISLC:

Open-world games with asset streaming (Hogwarts Legacy, Star Citizen): High benefit. These games constantly load and evict large texture sets, creating heavy standby churn.
Competitive shooters with small maps: Low benefit. The entire game fits in RAM with room to spare; standby buildup is slow.
Simulation games left running for hours (Microsoft Flight Simulator): High benefit. Extended sessions accumulate massive standby lists.

Troubleshooting

ISLC shows “Access Denied” on purge: Ensure you ran ISLC as Administrator, not just a regular user in the Administrators group. Right-click → Run as administrator explicitly.

Purge count stays at zero: Your standby list is never reaching the threshold. Lower the trigger value or verify the tool is actually monitoring (status bar should show current standby size updating).

System feels sluggish after purge: You set the threshold too low. Windows is purging useful cached data along with truly stale standby pages. Raise the threshold to 2048 MB and test again.

Summary

ISLC is a set-and-forget tool that addresses one of the most frustrating and least-discussed sources of gaming stutter on Windows. The configuration takes five minutes, the memory footprint is negligible, and the results — especially in long sessions with memory-hungry games — are dramatic. Install it, set your thresholds, automate it with Task Scheduler, and stop blaming your GPU for stutters that are actually a RAM management problem.