How to compare RAM behavior in two browser windows

You run a memory test in one browser window, then open another and get a different score. Or both tests slow down when they run at the same time. That does not automatically mean your RAM is failing. The browser, other programs, and the operating system all compete for time and memory bandwidth.

Use the Memory Test (RAM) to compare read, write, and copy speeds, response time, and the overall score. First check each window on its own, then run both tests together under the same conditions.

Compare the two windows

1. Open the Memory Test (RAM) in two separate browser windows on the same computer. Keep them in the same browser, if possible, so the browser and system conditions are consistent.
2. Run the test in the first window while the second is idle. When the test finishes, note the read, write, and copy speeds, response time, and score. Run the test in the second window by itself and note the same results.
3. Open both windows so you can see them, then start a test in each one close together. Let both finish. Note the results separately, and record whether either test takes longer, pauses, or fails.
4. Repeat the comparison once if the results are surprising. Close demanding programs first, keep the computer in the same power state, and avoid changing settings between runs.

Do not keep launching extra tests to force a failure. Two simultaneous memory tests can put a noticeable load on a computer, especially a laptop with limited available memory.

What the results mean

The two windows get similar scores

Your results are consistent under these conditions. That is useful for comparing the two runs, but it does not prove that every memory task will behave the same way. Other programs may use memory differently, and the test score is not a measurement of how much RAM is installed.

Both scores fall when the tests run together

The tests are sharing the computer's resources. They can compete for memory bandwidth, processor time, and the browser's attention. If both tests slow down by a similar amount, the change is more likely to reflect the combined workload than a problem isolated to one window.

One window slows down more than the other

That window may be receiving less time from the browser or operating system, particularly if it is in the background. Small differences can also come from normal variation between runs. Compare the read, write, copy, and response-time results rather than relying only on the overall score.

Browsers may reduce work in a window that is not active or visible. For more on that effect, see why RAM bandwidth changes with background browser tabs.

A test freezes or the browser becomes unresponsive

The combined workload may be too much for the available resources, or another process may already be using a lot of memory or processor time. Close the tests, wait for the computer to recover, and check each window on its own before trying a concurrent run again. A freeze by itself does not identify a faulty RAM module.

How to make the comparison fair

1. Close other demanding work. Pause large downloads, video editing, games, and other memory tests. Background work can change a score even if you do not interact with it.
2. Keep the windows visible. Arrange them side by side instead of leaving one minimized or hidden behind the other. This reduces the chance that the browser will treat one test as an inactive background task, though it cannot make the operating system schedule both identically.
3. Use the same power conditions. Compare both runs on battery or both while plugged in. If you change the power mode, Windows 11 has it under Settings › System › Power & battery › Power mode. On a Mac laptop, check System Settings › Battery and keep Low Power Mode in the same state for both runs.
4. Check for other activity. If scores change unexpectedly, close apps that are syncing files, updating, or running a call. Then compare one test at a time before testing both together again.
5. Repeat only a small number of times. Run a clean single-window comparison and one concurrent comparison. If results differ slightly on a repeat, treat that as normal variation unless the difference is large and consistent.

What this test can and cannot tell you

The Memory Test measures how the browser performs memory read, write, and copy work on this computer. Its response-time result and score help compare test runs, but the score is not a grade for your memory modules and cannot diagnose a physical fault on its own.

A browser also cannot read the exact amount of RAM installed. It gets only a rounded hint about memory size, so do not use a displayed amount or benchmark score as proof of capacity. For a comparison affected by background work, see why system load distorts memory test results.

If the computer crashes or shows memory errors outside this browser test too, save your work and use the computer's built-in memory diagnostics or ask a repair professional to check it.