Oblivion Remastered Performance Fix Mod: Windows 11 Install Guide, Benchmarks and Safety Checks

Here's what the mod changes, what the numbers do and don't show, and how to install it, check it and remove it safely if you want to try it on your own machine.

A remaster that never stopped hitching​

Commercially, the game was a hit. Players were much less happy with how it runs. Windows Central reports that stuttering, frame spikes, and poor optimization have been common complaints, often attributed to the use of Unreal Engine 5. DSOGaming points out that the game got two patches in July 2025, but nothing has come out since. It still has major stutters and poor performance.

The mod's GitHub page gives a clear technical explanation for the problem. Oblivion Remastered runs two engines at the same time: the original 2006 engine handles the game world, and Unreal Engine 5 draws it. Several steps in that pipeline run on a single CPU thread. When one of them is maxed out, the whole game waits. According to the project, that's why a town like Cheydinhal can drop to 30–40 fps while Task Manager shows the CPU only about 30% busy.

Section summary: The stutter is real, official patches stopped in mid-2025, and the slowdowns appear to come mostly from single-threaded bottlenecks, not a lack of raw GPU power.

Who built it, and how much did Claude actually do?​

The creator posts as LTSharpe on Reddit (LTSharpe26 on Nexus Mods). Wccftech reports that he explained how even upgrading from a GeForce RTX 2070 SUPER to a Radeon RX 9070 XT failed to resolve the game's performance problems on his Ryzen 7 5800X system. Frustrated by the situation, he turned to Claude Opus 5.5.

One small correction: Windows Central described his CPU as a "Ryzen 9 5800X." The 5800X is a Ryzen 7 part, and the project's own test-PC listing says Ryzen 7 5800X.

The project gives the AI a lot of the credit. The repository says Claude, working in Claude Code, did the profiling, the reverse engineering, the fixes, the benchmark and the documentation. LTSharpe set the goals and one firm rule (don't change how the game looks), made the decisions and played every build. VGTimes summarizes it this way: the project took about two and a half weeks and yielded around 40 engine-level fixes. Claude helped profile the game, analyze its engine, and develop fixes, while LTSharpe set the goal of preserving the image, made the decisions, and tested each build. Wccftech adds that the creator has no professional software development background.

Part of the method was simple: LTSharpe first built a repeatable benchmark so Claude had something objective to measure each change against. DSOGaming notes that first, he built a custom test tool. This let Claude find and fix slow spots in the game on its own. Nobody has independently audited how the work was split between human and AI, so treat that account as the creator's own description.

What the DLL actually changes​

This isn't an .ini preset that lowers your shadows. The mod is a small DLL that loads with the game. For each of its roughly 40 fixes, it finds a specific spot in the game's code, checks that the code is exactly what it expects, and changes how that code works, in memory only. The main areas, as the project lists them:

• Rendering: turning drawing work into DirectX 12 commands was done on one thread while other cores sat idle. The mod spreads that work across all cores, the way Unreal Engine 5.5 does. It also stops the weather system from rebuilding the sun, sky and fog every frame.
• Travel and memory: while you travel, the game released memory and then requested it again seconds later, which cost 20–100 ms each time. The mod keeps that memory reserved, up to a limit, and hands it back when Windows runs short.
• Physics streaming: physics rebuilds are spread over several frames, and new bodies are built on helper threads.
• Characters and cells: distant characters you can't see are built a little per frame. The cells behind you are unloaded one per frame instead of all at once.
• Menus: the full-screen menu background was filtered one pixel at a time, and the Graphics page asked Windows for every display mode eight times over. Both are now handled more efficiently.
• Frame generation: AMD frame-generation work is moved to the GPU's second queue.
• Crash guards: includes a fix for FSR staying switched off after an alt-tab.

The project says screenshots taken with the fix on and off were compared automatically across different times of day and weather. The differences were about the same size as those between two stock runs.

The numbers, with caveats​

Most coverage leads with "37%." That figure comes from the creator's video. Overclock3D reports that his mod reduces the number of stutters from 66 to 11 and increases the game's 1% low FPS from 18 FPS to 26 FPS. The repository has a more detailed results table, measured on a Ryzen 7 5800X, RX 9070 XT (16 GB), 32 GB of RAM, Windows 11 and Steam build 19115871:

Before you plan on 100 fps, keep a few things in mind:

• "4K" here means FSR Performance upscaling, with hardware ray tracing on, Ultra settings and High shadows. It is not native 4K.
• Each row is the mean or median of only two to four runs.
• The rows come from different builds. The Imperial City figure uses the current release. The Cheydinhal flight used an earlier build with about two-thirds of today's fixes, and the street, door and menu rows used the first third.
• Your CPU/GPU balance matters a lot. VGTimes notes that the beta has so far been tested on only one PC, equipped with a Ryzen 7 5800X and Radeon RX 9070 XT and running Windows 11. LTSharpe says results vary by hardware, with the largest gains when the CPU is the bottleneck. If your GPU is already the limit, the project says your frame rate will barely change, though the hitch, door and menu fixes still help.

Early user reports look good but are anecdotal. Overclock3D says one Ryzen 7 5800X3D user reporting a 50% FPS improvement. Techtroduce sums it up: the reported performance gains have not been independently established across a broad selection of CPUs and GPUs.

Section summary: The gains are measured, repeatable and impressive on one AMD system. They're a strong lead to follow up on, not a guarantee for every PC.

How to install it (Steam)​

These steps follow the project's own instructions:

1. Download OblivionPerfFix-<version>.zip from the project's GitHub Releases page or its Nexus Mods page. Both host the same files.
2. In Steam, right-click Oblivion Remastered and choose Manage > Browse local files.
3. Extract the zip into that folder. This places version.dll and OblivionPerfFix.ini in OblivionRemastered\Binaries\Win64\.
4. Launch the game.

How to tell it's working: open OblivionRemastered\Binaries\Win64\OblivionPerfFix.log. It lists each fix as it's applied. All fixes are on by default, and each has its own on/off switch (1 or 0) in the .ini file.

Other setups:

• Vortex or Mod Organizer 2: install the same zip as a mod. In MO2 the files have to end up in the game's root folder, not Data. Use the Root Builder plugin or extract them by hand.
• OBSE64, or another mod that already uses version.dll (some upscaler mods do): don't overwrite that file. Use the -OBSE.zip package instead, which installs to OBSE\Plugins\. A few fixes can't load this way, and the log tells you which.
• Xbox / PC Game Pass: this version is experimental. Nexus Mods lists it as experimental, not tested by us yet: download "OblivionPerfFix GamePass". It puts the files into OblivionRemastered\Binaries\WinGDK\ in the game's folder (usually C:\XboxGames\The Elder Scrolls IV - Oblivion Remastered). If no log file appears, the mod didn't load.
• Steam Deck/Linux (untested): install as for Steam, then add WINEDLLOVERRIDES="version=n,b" %command% to the game's launch options.

Common problems​

• Fewer than 8 logical processors: the fixes that depend most on helper threads stay off by default, and the log says so. You can force them on with ParallelMinProcessors=6 under [Fixes] in the .ini. The author could only test this on a 16-thread CPU.
• After a game update: if a piece of code no longer matches what a fix expects, that fix switches itself off and logs it. The game then behaves as if that fix weren't installed.
• Updating the mod: extract the new zip over the old files. New fixes add new .ini keys, so any custom settings have to be entered again.
• Antivirus warnings: see the next section.
• Removing it: delete version.dll, OblivionPerfFix.ini and the OblivionPerfFix*.log files from Binaries\Win64\ (Binaries\WinGDK\ for Game Pass). The project says nothing on disk is changed and your saves don't depend on the mod.

The security question​

A DLL named version.dll that loads into a game process is a standard modding technique. Malware uses the same trick, which the maintainer openly acknowledges. The project says:

• Releases are built by GitHub Actions from the public source, not on someone's personal PC.
• Each release lists SHA-256 checksums and carries a build attestation you can check with gh attestation verify OblivionPerfFix-<version>.zip --repo LTSharpe/OblivionRemasteredPerformanceFix.
• The DLL makes no internet connections, doesn't touch the registry, links only to kernel32.dll, and writes nothing except its own logs.

These are the project's own claims, not an independent security audit. The source code is heavily commented C++, one file per fix. If an antivirus flags it, don't just click "allow." Compare the checksums and download only from the official GitHub or Nexus pages. Copies on random re-upload sites are exactly where something nasty could be slipped in.

Our take​

Calling this "vibe coding" undersells it. The method behind it is sound engineering: a reproducible benchmark, stock and modified builds tested in alternation, fixes that disable themselves when the code doesn't match, and automated screenshot comparisons. The AI apparently wrote most of the code. The human supplied the discipline, and that discipline is why the results are worth taking seriously.

Some skepticism is still warranted. Overclock3D's headline-friendly framing that one gamer did in weeks what Microsoft couldn't in 18 months skips over the realities of shipping on several platforms. A studio has to support every GPU vendor, Xbox consoles, and certification, while a hobbyist can hand-tune for one Ryzen and Radeon pair. That said, the mod's openly published list of single-threaded bottlenecks is something Bethesda and Virtuos could look at.

For now, if you play on a CPU-limited Windows PC and are comfortable with beta software, the gains look worth trying. Just check the log, verify the files you downloaded, and post your benchmark results to the project so the evidence covers more than one machine.