Grand Theft Auto IV is a sprawling open-world action-adventure set in a detailed recreation of New York City called Liberty City. Players spend most of their time driving, completing story missions, engaging in third-person shooting, and freely exploring a living city packed with pedestrians, traffic, and dynamic events. On PC the Complete Edition bundles the base game and both expansions, but the 2008 RAGE engine remains notoriously unoptimized for modern hardware. Most players today run it as a single-player experience, often installing community fixes and visual mods to restore smoothness and increase fidelity that the vanilla version lacks. At 1080p the resolution itself is modest, yet performance is still dictated far more by the CPU than the GPU. The engine relies on high volumes of draw calls, AI calculations for crowded streets, physics during chases or explosions, and constant world streaming as you drive between boroughs. These loads create the classic GTA IV pain points: micro-stutters, inconsistent frame pacing, and sudden dips when traffic density or draw distance is raised. Even though the base visuals look dated, turning up view distance, shadow quality, and detail levels quickly exposes how CPU-sensitive the game remains. Many new builders mistakenly buy a powerful GPU while using an older or low-thread CPU, only to discover the game still hitches in dense areas. Common misunderstandings include assuming the game will run plug-and-play on new hardware or that a high-end graphics card alone will solve every issue. In reality the DirectX 9 code is poorly threaded, leading to high CPU usage even at low settings. This is where mods become essential. Tools like FusionFix and DXVK translate the game to Vulkan, dramatically reducing stutters and improving frame consistency. With those fixes applied, 1080p becomes the sweet spot where players can push traffic density, draw distance, and extra visual mods without constant interruptions to immersion. Before choosing parts, understand that a sensible 1080p GTA IV PC must deliver consistent frame delivery and low latency in motion above all else, which requires deliberate CPU priority rather than raw GPU horsepower.