How to Check VRAM Usage and What Browser Texture Allocation Means

When a game stutters after a texture-quality change, memory pressure is one possibility. To investigate it, use telemetry from the operating system, graphics driver, or a supported monitoring application while the game runs. GPUtest.org does not expose a live physical VRAM usage meter.

Keep usage, allocation, and capacity separate

• Capacity is the memory available to the physical adapter.
• Usage telemetry is an operating system or driver reading with its own accounting rules.
• Requested texture storage is the size an application asks an API to create.

These are not interchangeable. A browser may use shared memory, copy resources, impose limits, or lose its WebGL context. Successful allocation does not identify which physical memory cells hold the texture.

What the browser check does

The texture readback check requests square 1024×1024 textures in RGBA8 format. Each texture has a nominal pixel payload of 4 MiB. A shader writes a pattern into a framebuffer attached to the texture. The implementation reads the framebuffer twice and compares a byte every 4096 bytes.

The allocated counter adds nominal texture payload sizes. It is not a reading from a VRAM sensor. The comparison samples a small part of the data and does not compare every byte against an independently calculated expected pattern. Even a zero mismatch result cannot exclude a physical memory defect.

Run the check conservatively

Read the guide, start with a modest memory target, and keep unrelated applications closed. Increase the target only when the smaller run succeeds. Stop and reduce it if the browser becomes unresponsive or the context is lost. A browser allocation limit is not proof that the card lacks the corresponding physical capacity.

Record target size, completed blocks, mismatches, browser version, and any console error. Reproduce an unexpected mismatch before drawing conclusions, and use a dedicated native diagnostic for a serious memory fault investigation.

Investigate a game separately

Compare the same scene with two texture settings while recording memory telemetry and frame delivery from that game. Keep resolution and other quality settings fixed. If the change helps, document it as a game-specific result; texture quality can affect more than memory usage.

For API behavior see WebGL readPixels. For reporting conditions use our methodology.