How to compare power modes with a browser CPU score

Your laptop feels faster in one power mode, or you want to know whether a setting makes a real difference. A browser CPU score can help you compare, but only if you keep the test conditions consistent. Otherwise, heat, charging state, or background activity can look like a power mode effect.

The Processor Test measures single-core and all-core speed and gives each result a score out of 100. Use it to compare modes on the same computer, not to rank your device against every other computer.

Compare the power modes

1. Open the Processor Test on the computer you want to check. Use the same browser for every run.
2. Choose a power mode in your system settings. Note the mode and whether the laptop is plugged in or running on battery.
3. Run the test and note both the single-core and all-core scores. Also note the room conditions and whether the fan was already running loudly.
4. Let the computer cool down if it became warm, then switch to another power mode and repeat the test under the same conditions.
5. Run each mode at least twice. Compare the results for each mode, rather than relying on one unusually high or low score.

For a useful check, test your usual mode, then the mode you want to compare, and then your usual mode again. If the last result is much lower than the first, the computer may have warmed up or picked up background work during the test. Repeat the comparison after it has cooled down.

What the result means

Both scores rise in a higher-performance mode

The setting may be allowing the processor to run faster, especially during the all-core test, which keeps multiple CPU cores busy. A higher score does not necessarily mean everyday tasks will feel noticeably quicker. It shows that the browser test completed more work under those conditions.

The single-core score changes more

Single-core speed reflects work that depends heavily on one processor core. A mode can change how quickly the CPU boosts for a short task without making a similar difference when many cores are busy. Compare the same score type across runs, not the single-core result in one mode with the all-core result in another.

The scores are close or overlap between runs

The difference may be smaller than normal run-to-run variation. Background tasks, browser activity, and small changes in temperature can shift the score. If the gap is only a few points and the repeated results overlap, the test has not shown a clear performance difference for this workload.

The second mode scores lower

This does not automatically mean the mode is slower. The computer may have heated up during the first test, or another app may have started using the CPU. Cool the device, close unnecessary apps, and repeat the runs in a different order. If the lower result follows the mode across repeated comparisons, that mode may be limiting performance for this test.

How to make the comparison fair

1. Keep the power source the same. Compare plugged-in runs with plugged-in runs, or battery runs with battery runs. Some computers use different limits on battery power. Avoid changing the charger, dock, or connected display between runs.
2. Set the mode in system settings. In Windows 11, open Settings › System › Power & battery › Power mode and select the mode you want to test. On a Mac, open System Settings › Battery. If your Mac shows Energy Mode, choose the same available mode for each comparison. Options depend on the Mac model and whether it is on battery or connected to power.
3. Close other heavy work. Pause large downloads, video exports, game updates, and other CPU-intensive tasks. Keep the same ordinary apps open for every run, and avoid switching tabs while the test is running.
4. Control heat and timing. Start with the computer at a similar temperature each time. If the fan speeds up or the case becomes warm, wait for it to cool before testing the next mode. A processor may reduce its speed to manage heat.
5. Use one browser and one test page. Browser engines can produce different benchmark results, so do not compare a run in one browser with a run in another. For more context, see why CPU benchmarks differ across browser engines.
6. Write down the conditions. Record the mode, plugged-in or battery state, browser, scores, and whether the computer was warm. This makes it easier to spot a pattern instead of guessing from memory.

What this score cannot tell you

The score is a comparison of browser CPU performance, not a direct reading of processor temperature, electrical power use, or battery life. A higher score does not prove that a mode is best for your regular apps, and a lower score does not by itself show that the processor is faulty. Results can also vary with browser versions and system activity.

To compare battery life, you would need to measure how quickly the battery drains during the same task over a longer period. For CPU performance, use repeated runs on the same device and treat small differences cautiously.