Windows Idle Memory Census: In Use by Installed RAM

How much memory Windows uses before you open anything decides how much of a 16 GB machine is left for a game. The answers in circulation are single machines. They do not agree. One machine’s number says little, because it depends on how much memory is installed, what starts with Windows, and how long ago the machine booted. Microsoft has the subject on its list. On July 31, 2026 Pavan Davuluri wrote on the Windows Insider Blog, under the heading “What happens between now and the end of the year”, that Windows is expanding into four new focus areas. One is “Memory optimization for 8GB and above”, described as “Reducing Windows memory footprint”. A baseline taken now, from many machines, is what a later reading can be set against.

This page opens that census. One row is one machine, read once with the counters Windows keeps. The data, the field definitions, the validator and the report form live in the open repository: github.com/iBlessi/techfuelhq-census (CC BY 4.0).

If the question behind this is which memory to buy, prices are in the DDR5 buying guide and the RAM price index. If it is what to remove from Windows, that is in debloating Windows 11.

How results are reported

For each amount of installed memory the census gives the number of machines, the median memory in use, the lowest and highest, the median committed memory and the median number of processes.

It publishes no verdict on Windows and no advice on how much memory to buy. It reports where machines start.

What the numbers mean

The first three are worked out from Microsoft’s own table.

What one row records

A row is one machine, read once. Of its 22 fields, you fill in 2, the reading fills in 16, 2 are worked out from the row and the maintainer sets 2.

What the machine was doing

I keep the row from a machine that has been up for hours, with a browser open and a game launcher in the tray, and leave it out of the published figures. It is a different measurement.

How to take the reading

1. Restart the machine and sign in straight away. The command counts minutes from the start of Windows, not from signing in.
2. Leave it alone and open nothing. Take the reading 5 to 60 minutes after the restart.
3. Open PowerShell, which needs no administrator rights for this, paste the line below and press Enter.
4. Copy the one line it prints into the builder below.

$o=Get-CimInstance Win32_OperatingSystem;$m=Get-CimInstance Win32_PerfFormattedData_PerfOS_Memory;$d=@(Get-CimInstance Win32_PhysicalMemory);$s=$m.StandbyCacheNormalPriorityBytes+$m.StandbyCacheReserveBytes+$m.StandbyCacheCoreBytes;[ordered]@{census='windows-memory';v=1;installed_gb=[int](($d|Measure-Object Capacity -Sum).Sum/1GB);visible_mb=[int]($o.TotalVisibleMemorySize/1KB);available_mb=[int]($m.AvailableBytes/1MB);committed_mb=[int]($m.CommittedBytes/1MB);commit_limit_mb=[int]($m.CommitLimit/1MB);cache_mb=[int]($m.CacheBytes/1MB);standby_mb=[int]($s/1MB);modified_mb=[int]($m.ModifiedPageListBytes/1MB);free_mb=[int]($m.FreeAndZeroPageListBytes/1MB);paged_pool_mb=[int]($m.PoolPagedBytes/1MB);nonpaged_pool_mb=[int]($m.PoolNonpagedBytes/1MB);processes=@(Get-Process).Count;startup_items=@(Get-CimInstance Win32_StartupCommand).Count;uptime_min=[int]((Get-Date)-$o.LastBootUpTime).TotalMinutes;os_caption=$o.Caption;os_build=$o.BuildNumber}|ConvertTo-Json -Compress

The command reads memory counters, counts processes and startup entries, and reads the Windows edition and build. It prints no process name, computer name or user name. It was run without administrator rights on Windows 11 build 26200 before publication, on a machine that had been up all day, and what it printed is one of the test files in the repository.

Send a report

Sending needs a GitHub account, because the report is filed as an issue. No account? Copy the report and email it to contact@techfuelhq.com.

What has been published

Current count: 0 reports. No group has rows yet, so nothing is published.

An amount of installed memory publishes at five machines, each read 5 to 60 minutes after a restart. Below that it is listed as collecting, with its count and no figures. Nothing is published yet.

Limits of this data

• Reports come from people who chose to send them, and people who read a hardware site run more at startup than most. The figures describe the machines in the dataset.
• “Left alone” is the owner’s word. The row carries minutes since boot and the process count, which show when a machine was busier than its owner thought.
• A machine with a laptop maker’s software is a different starting point from a clean install. The row does not record which it is.
• The census measures memory held at rest. It does not measure how a machine behaves when memory runs short.

Use the data

The dataset is one file. submissions.csv holds one row per machine, in the field order above, under Creative Commons Attribution 4.0. Attribute it as “TechFuelHQ open census” with a link to this page.

The coil whine census is the sibling dataset that started this series.

Change log

• 0.1.0 (2026-09-29): fields, the Windows command, validator and intake form. The census opened with 0 rows.