Low fill rate after a driver update on a Mac

Your Mac’s graphics score dropped after an update, and the fill rate is much lower than you expected. That can point to a change in the browser or power settings, but one browser test cannot confirm that the GPU is damaged.

Use the GPU Test to repeat the same 1080p graphics workload, then compare the results under consistent conditions. The checks below help separate a real slowdown from a one-off result or a browser change.

Check the fill rate again

1. Open the GPU Test on the Mac you want to check and run the test in a foreground browser tab.
2. Connect the Mac to power, close graphics-heavy apps, and wait until the computer is not busy with startup tasks.
3. Run the test three times. Note the fill rate and the score out of 100 each time, along with your browser and macOS versions.
4. If you can, repeat the test in a second browser. Keep the Mac plugged in and use the same screen setup for both tests.

The test uses a 1080p workload. Changing your display resolution does not make it a different native-resolution test, but connected displays and other active graphics work can still affect how the Mac behaves while the test runs.

What the result means

The score is low once, then returns to normal

A temporary slowdown is more likely than a lasting graphics problem. Background updates, a busy browser, or heat can affect a short test. Use the repeated results, not the single lowest run, when comparing performance.

The score is consistently low in one browser

This points more toward that browser’s graphics settings, version, profile, or extensions than toward a clear hardware fault. If another browser performs normally under the same conditions, start with the browser that reports the low result.

The score stays low in multiple browsers

A system-wide change is more plausible, such as a power setting, a macOS graphics update, or heat-related slowdown. It still does not prove the GPU is defective. A browser test measures a particular workload, not every graphics task your Mac can run.

The test looks corrupted or stops responding

That may be a browser graphics issue rather than a low-performing GPU. Reload the page, restart the browser, and check whether the same behavior happens in another browser before drawing conclusions.

How to fix it

1. Restart the Mac and repeat the test. A restart clears temporary browser and graphics processes left over after an update. Wait a few minutes after signing in, then run the test by itself.
2. Check graphics acceleration in the browser. In Chrome or Edge, open Settings and search for graphics acceleration. If Use graphics acceleration when available is off, turn it on and relaunch the browser. Safari does not offer the same user-facing switch.
3. Check for another update or a restart prompt. Open System Settings › General › Software Update and install any available macOS update from Apple. Update the browser separately using its own update page or menu, then restart it. Avoid downloading a Mac graphics driver from an unfamiliar site.
4. Check power mode. In System Settings › Battery, turn off Low Power Mode for the comparison. If your Mac offers an Energy Mode choice, use Automatic or High Power while plugged in. The available options vary by Mac model and macOS version.
5. Reduce competing graphics work. Close games, video editors, other graphics tests, and high-resolution video streams. Disconnect an external display for one run, then reconnect it and test again if you normally use one.
6. Check whether an extension or browser profile is involved. Try a fresh browser profile without extensions, then compare it with your usual profile. If the fresh profile scores better, re-enable extensions one at a time to find a possible cause.

When the GPU may need service

Consider a hardware check if the low result persists after a restart, in more than one browser, while the Mac is plugged in and cool, and you also see graphics glitches or crashes in other apps. Colored blocks, repeated visual corruption, or unexpected shutdowns are more concerning than a low score by itself.

Back up important files before arranging service. Contact Apple or an authorized repair provider with the Mac model, macOS version, browser version, and your repeated test results. A browser score alone is not enough to identify a failed GPU or justify replacing a part.

Why an update can change a browser score

Mac graphics drivers are normally delivered as part of macOS rather than as separate driver packages. So an update you call a driver update may have changed macOS, the browser, or a graphics-related utility. Browsers also rely on their own graphics software and settings to run a web-based test, which means the result can change even when the Mac’s physical GPU has not changed.

The fill rate describes how quickly the test handles a specific graphics workload. It is useful for comparing the same Mac under similar conditions, but it is not a universal measure of gaming performance or a diagnosis of GPU health.