What's the difference between VSync and a frame rate cap?

VSync (vertical sync) synchronizes your game's frame output to the display's refresh rate to prevent screen tearing, it's tied to the monitor and caps frames to its refresh rate as a side effect, but can add input latency. A frame rate cap simply limits how many frames per second the game renders to a number you choose, independent of the display, to reduce CPU/GPU work, heat, and battery drain, or improve consistency. They overlap but solve distinct problems.

Should I use VSync or a frame rate cap?

Use VSync when screen tearing is your concern, it synchronizes frames to the display to eliminate tearing. Use a frame rate cap to reduce unnecessary resource use (heat, battery, especially on mobile) or to target a sustainable, consistent frame rate independent of the display. They solve different problems, so the choice depends on whether you're fighting tearing (VSync) or managing performance, power, and consistency (cap). They can even be used together.

Does a frame rate cap prevent screen tearing?

No, a frame rate cap just limits how many frames per second you render; it isn't synchronized to the display's refresh, so it doesn't prevent tearing. Tearing happens when frame output isn't aligned with the monitor's refresh, which is what VSync addresses by synchronizing the two. A cap reduces resource use and can improve consistency, but to eliminate tearing you need VSync (or a similar display-synchronization technique), not just a frame rate limit.

VSync vs Frame Rate Cap

Quick answer: VSync synchronizes frame output to the display's refresh rate to prevent screen tearing; a frame rate cap limits how many frames per second the game renders, independent of the display. They solve overlapping but distinct problems.

VSync and frame rate caps both limit frame output, so they're often confused, but they work differently and solve different problems. Knowing the distinction helps you choose the right tool. Here's the comparison.

What VSync Does

VSync (vertical synchronization) synchronizes your game's frame output to the display's refresh rate, presenting a new frame only when the monitor refreshes. Its primary purpose is preventing screen tearing, the visual artifact where parts of two frames show at once, which happens when frame output isn't aligned with the display.

VSync is tied to the display's refresh rate (e.g. 60Hz), so it effectively caps frames to that rate as a side effect, but its job is tearing prevention via synchronization. The trade-off is potential added input latency and, if the game can't keep up, larger frame-rate drops. VSync is about the display relationship.

What a Frame Rate Cap Does

A frame rate cap simply limits how many frames per second the game renders, to a number you choose, independent of the display. Its purposes are different: capping reduces unnecessary CPU/GPU work, heat, and battery drain (rendering 200 FPS when 60 suffices wastes resources), and can improve consistency by targeting a sustainable rate.

A cap doesn't prevent tearing (it's not synced to the display) and doesn't carry VSync's latency characteristics. Bugnet's performance data helps you choose a cap a device can sustain. A frame rate cap is about resource use and consistency, not the display synchronization VSync provides.

How They Differ and When to Use Each

They overlap (both limit frames) but solve distinct problems: VSync prevents tearing by syncing to the display; a cap limits resource use and targets a sustainable rate independent of the display. Use VSync when tearing is the concern; use a cap to save power/heat or improve consistency. They can even be used together.

Bugnet's performance and sustained-load data helps you decide, e.g. whether an uncapped rate is causing thermal problems a cap would fix. So distinguish them: VSync is display synchronization for tearing, a frame rate cap is a resource-and-consistency tool, and choose based on whether you're fighting tearing or managing performance and power.

VSync synchronizes frames to the display's refresh to prevent tearing (display-tied, can add latency); a frame rate cap limits FPS independent of the display to save power and improve consistency. Distinct problems, choose by your concern.