MW4 Beta PC Fixes: Shader Pre-Loading and Fewer Restarts

A game that begins compiling shaders only after the player presses Play has placed its longest delay directly in the way of a match. The Call of Duty: Modern Warfare 4 beta changes that sequence on PC: shader pre-loading begins after the download completes, while more data patches can apply without forcing the familiar “Update Requires Restart” cycle.

Infinity Ward and PC partner Beenox are targeting two persistent Modern Warfare III Season 4-era frustrations: launch-time “Compiling Shaders” waits and small updates that turn into multiple full game restarts. The beta starts on 21 August 2026 after Call of Duty: Next, with shader pre-loading scheduled to begin on 20 August at 9am PT, 12pm ET, and 5pm BST.

For clarity, this analysis uses Modern Warfare 4 and MW4, the working name used for the beta. Modern Warfare III Season 4 remains the relevant comparison point because its PC build regularly required shader cache rebuilding at first launch, after major patches, and following GPU driver changes.

The relevant PC change: move shader work before the first match

Shaders are small programs compiled for a specific game build, graphics driver, GPU, and graphics configuration. They are necessary, but compiling a large cache while the game is opening is poor scheduling. It produces an idle loading screen at best and can contribute to frame-time spikes during the first few matches if the cache remains incomplete.

MW4’s beta shifts part of that work into the post-download period. Once the beta is installed, Windows may show a system-tray notification stating “Shader Pre-Loading Will Start.” The practical objective is simple: generate and cache shader work before the player reaches the title screen rather than holding the game hostage at “Compiling Shaders.”

This is a scheduling improvement, not a claim that every PC will have zero shader activity on first boot. A fresh driver install, a large game patch, a damaged cache, or a graphics-setting change can still create shader work. The useful benchmark is whether the wait is materially shorter and whether the first match carries fewer abrupt frame-time spikes than the second and third.

Platform	Shader pre-loading behavior	Data-patch restart behavior during beta	Practical limitation
Battle.net on PC	Begins automatically after the download completes.	Most data patches apply without a restart.	A patch arriving during an active game session can still require a restart.
Steam on PC	Pre-loading is supported, but first launch can still show a shorter shader-compilation phase.	Most data patches apply without a restart.	Steam’s first-run behavior is less complete than Battle.net’s automatic flow.
Xbox app on PC	Shader pre-loading is part of the PC beta initiative, though its launcher-specific first-run behavior is not detailed.	Most data patches apply without a restart.	Players should record whether background pre-loading triggers and how long first launch takes.
PlayStation 5	PC shader pre-loading does not apply.	Receives the intended reduction in restart-required updates.	Console behavior remains separate from the PC shader pipeline.
Xbox consoles	PC shader pre-loading does not apply.	Restarts are still required to apply updates during the beta.	The developer is working to reduce these cases for release.
Nintendo Switch 2	PC shader pre-loading does not apply.	Restarts remain required during both beta and launch.	No reduced-restart rollout is planned for this period.

Battle.net has the cleanest planned first-launch path

Battle.net is the key implementation to watch because it starts shader pre-loading automatically after the MW4 beta download finishes. If that process completes before the first launch, Battle.net should offer the closest version of the intended experience: no major interactive shader wait, followed by a cache ready for the first multiplayer session.

Steam supports the same broader pre-loading approach, but its first run still includes a shorter “Compiling Shaders” phase. That is an improvement over the older model, where shader compilation could dominate first launch entirely, but it prevents Steam and Battle.net from being treated as identical. A player comparing the two should measure both first-run and repeat-launch behavior rather than relying on the first loading screen alone.

The Xbox app on PC receives the reduced-restart data-patch behavior, but its specific shader pre-loading flow is less clearly defined. This is exactly the sort of beta detail that needs measurement instead of assumptions. A shared PC feature label does not guarantee matching launcher integration.

“Fewer restarts” applies to data patches, not every update

The “Update Requires Restart” prompt has been particularly irritating in recent Call of Duty PC builds because a small content update could interrupt a session, force a full reboot, and occasionally repeat the prompt after relaunch. MW4 changes the delivery path for more data patches on Steam, Battle.net, and the Xbox app on PC, allowing those patches to apply without a restart in most situations.

The boundary matters. A full title update can still need a restart because it may replace executable files or rendering components that cannot safely be swapped while the process is running. A data patch that lands while the player is already in-game can also require a restart after the session ends or after the game disconnects. The beta reduces interruption frequency; it does not turn the Call of Duty client into a permanently hot-swappable application.

That distinction should eliminate a common misread of the feature. A single restart after a substantial update is expected behavior. Repeated restart requests after a small data patch has already downloaded are the failure case this new pipeline is intended to prevent.

A useful PC beta test plan

The beta should be tested as a launch and frame-time problem rather than reduced to an average-FPS comparison. Shader changes rarely create a meaningful average-frame-rate gain by themselves. Their value lies in reducing work at the wrong time: the first launch, the first menu transition, and the first match after a patch or driver change.

Test area	What to record	Why it matters
Post-download behavior	Whether a Windows notification appears and the time between download completion and first game launch.	Confirms whether shader pre-loading started before the game was opened.
First launch	Time from launcher click to main menu, plus any “Compiling Shaders” percentage screen.	Measures the interactive delay MW4 is designed to reduce.
Repeat launches	Two additional cold launches after closing the game normally.	Separates a one-time cache build from a persistent launch problem.
First three matches	Frame-time spikes, short hitches, and texture or geometry pop-in under the same settings.	Identifies shader work that has shifted into gameplay instead of finishing before it.
Small data patch	Restart prompt count, successful patch application, and any repeat-prompt loop.	Tests the claimed reduction in “Update Requires Restart” interruptions.
Driver update or major game patch	Whether shader work resumes and whether the rebuild completes cleanly.	Checks expected cache invalidation behavior rather than treating it as a bug by default.

Storage type should be written down with every result. The beta materials do not provide load-time targets for NVMe SSDs, SATA SSDs, or hard drives, so there is no basis for a universal seconds-saved claim. It remains important context because background shader creation reads and writes a cache before the player reaches the menu, and slower storage can alter how that work feels.

Likewise, results should distinguish an ordinary first-run cache build from a stuck compile. A short Steam first-launch phase is part of the stated design. A compile screen that never completes, repeats every launch, or produces heavy hitches well into later matches deserves separate troubleshooting.

TPM 2.0 and Secure Boot are gate checks, not optional tuning

PC access to the MW4 beta requires TPM 2.0 and Secure Boot. These are eligibility requirements. A system with a capable CPU and GPU can still be blocked before it reaches the shader-pre-loading stage if either firmware setting is disabled or the machine is configured for legacy boot.

• Press Windows key + R, enter tpm.msc, and confirm that Windows reports “The TPM is ready for use” with specification version 2.0.
• Press Windows key + R, enter msinfo32, then confirm BIOS Mode: UEFI and Secure Boot State: On.
• In motherboard firmware, TPM settings may appear as AMD fTPM, AMD PSP fTPM, or Intel PTT. Secure Boot is usually located under the Boot, Security, or Trusted Computing menus.
• Systems still using CSM or Legacy BIOS mode may need CSM disabled and a GPT-formatted boot drive before Secure Boot can be enabled.

The last item is the one that creates avoidable trouble. Changing firmware boot settings without confirming the existing Windows installation supports UEFI and GPT can leave a machine unable to boot normally. The check belongs before beta day, with enough time to update BIOS firmware or correct an old installation if necessary. Some older boards do not provide TPM 2.0 support at all.

What this improves over Modern Warfare III Season 4

Modern Warfare III Season 4 established the old baseline: shaders commonly compiled at first boot, after driver changes, and following major patches. The recovery route in that generation often involved manually selecting “Restart Shaders Pre-Loading” in graphics settings or rebuilding the shader cache after corruption. Those steps can still be relevant when a cache fails, but they are poor substitutes for a launcher-aware process that completes before the game opens.

MW4’s approach is technically sensible because it moves predictable work away from the moment when the player is waiting to enter a match. The caveat is equally straightforward: the work has not disappeared. It has shifted into the post-download window, and the beta needs to show that the cache remains valid through repeat launches, patch delivery, and driver updates.