Low GPU usage and high CPU usage in games: bottleneck or normal?

What the two usage figures are telling you

Every frame is a relay. The processor runs the game's logic, works out what is on screen and prepares instructions; the graphics card then draws the frame. If the processor can prepare frames faster than the graphics card can draw them, the card works at full capacity. If the processor cannot keep up, the card finishes each frame and waits, and its usage reading falls.

So low graphics card usage alongside a busy processor means the processor is setting the pace. Whether that is a problem depends entirely on whether the resulting frame rate is the one you want.

When low GPU usage is not a problem at all

Several ordinary situations lower graphics card usage without anything being wrong:

• A frame cap or VSync. If the game is capped at your monitor's refresh rate and reaching it, the card has nothing more to do. Check whether the frame rate sits exactly on a cap; if it does, low usage is the cap working.
• A light game or a menu. Older or simpler games, and menus in any game, ask very little of a modern card.
• An engine limit. Some games cap their own frame rate internally, or cannot use more than a few processor threads, whatever hardware they run on.

In each case the fix is not to make the card work harder. It is to be sure the frame rate you are getting is the one you need. If it is, there is nothing to solve.

Why total processor usage misleads

Task Manager's headline processor figure is an average across every core. Games usually lean heavily on one or two main threads, so a single core can be completely saturated, and holding back the whole game, while the overall figure looks modest. That is why people often dismiss a processor bottleneck because "the CPU is only half used".

To see the truth, switch Task Manager's processor graph to show logical processors, or use an on-screen display that reports usage per core. A game held back by its processor typically shows one or two cores pinned near their maximum while the graphics card waits.

Real causes of a processor bottleneck

Fixes, from free and quick to expensive

Work down this list and stop when the frame rate is where you want it. The first steps cost nothing, and only the last one costs money.

Close background load first. Browsers with video, recording software and launchers all compete for the same cores the game needs. Check the power setting next: Balanced plans and laptop energy modes can hold processor cores back, and core parking and processor states explains what those settings control.

Check memory. Many PCs run memory below its rated speed because the profile was never enabled in the firmware, and a single module, or two modules in the wrong slots, halves memory bandwidth. The XMP and EXPO reference covers memory profiles and their caveats. Then adjust the game: processor-heavy options such as view distance, simulation detail and player counts often matter far more than graphics quality in a CPU-limited game.

If a processor bottleneck remains in the games you care about after all of that, the honest answer is hardware. No Windows setting can make a processor's cores faster than they are.

Game settings that move load between processor and graphics card

Knowing which settings load which component lets you rebalance a game deliberately instead of lowering everything. Settings that mainly load the processor include view or draw distance for objects and characters, crowd and traffic density, physics and destruction detail, and in some games shadow distance and the number of players or units being simulated. Settings that mainly load the graphics card include resolution and resolution scaling, anti-aliasing, ambient occlusion, reflections and most post-processing effects.

In a game limited by the processor, reducing the first group can make a clear difference while the second group barely matters, so graphics quality can often stay high. The reverse holds when the graphics card is the limit. Change one setting at a time and watch which usage figure moves, because games do not always label their options in a way that makes the split obvious.

On laptops, confirm which graphics processor the game uses

Many gaming laptops have two graphics processors: a low-power one built into the processor and a dedicated card. If a game runs on the built-in one, the dedicated card shows almost no usage while the processor works hard, which looks exactly like a bottleneck. Task Manager's Processes tab can display a GPU engine column that names the graphics processor each program is actually using.

To fix it, open Settings, System, Display, Graphics, choose the game, and set it to use the high-performance graphics processor; the NVIDIA and AMD control apps offer the same choice for each program. Make sure the laptop is plugged in as well, since some models restrict the dedicated card on battery, and check any manufacturer mode that switches between the two graphics processors.

Fixes that do not work

A few popular remedies for high processor usage do little or nothing. Changing Windows' foreground priority values rarely alters anything on a modern desktop, as the Win32PrioritySeparation reference explains. Setting a game to high priority in Task Manager seldom helps when the game is already the busiest program. Memory cleaners that empty Windows' cache force it to be rebuilt, which adds work rather than removing it. And forcing every core to stay awake with third-party tools duplicates what a performance power plan already does.

Where an optimizer fits

An optimizer can help with two causes above: background load and power behaviour. It cannot raise per-core speed, enable a memory profile in firmware or change how a game engine uses threads. Which optimizer changes affect FPS explains the categories in more detail, and if your frame rate also dips unpredictably, the random FPS drop guide covers intermittent causes.

JINSHI PC Tweaks is our product. Its power and background settings are listed with their registry paths on the complete tweak list, each reversible individually, and everything it changes can also be done by hand for free. If you would rather apply those together, the JINSHI Tweaks homepage explains what PC Tweaks covers. For choosing any tool, see how to choose a PC optimizer for gaming.