Rainbow Six Siege FPS drops after warmup: 3 checks to find the cause
By Ryan Mercer Updated 12 min read
On this page (8 sections)
- The short version
- Why FPS drops after warmup in Rainbow Six Siege
- Check 1: Test if temperature is causing FPS drops
- Check 2: Spot memory or resource leaks causing FPS loss
- Check 3: Driver and shader cache conflicts causing delayed drops
- What the monitoring numbers mean and how to act on them
- When the checks show nothing wrong but FPS still drops
- Questions people still ask
In short: FPS drops after warmup in Rainbow Six Siege usually mean thermal throttling once the GPU crosses 80–85 °C, a memory leak filling VRAM over several rounds, or shader compilation stutter tied to a corrupted cache. Run the three checks below to pinpoint which.
Warmup FPS drops in Siege trace to three causes: thermal throttling past 80 °C, VRAM leaking over multiple rounds, or corrupted shader cache.
| Throttle threshold | 80–85 °C GPU, varies by card |
|---|---|
| Normal VRAM use | 4–6 GB at 1080p high |
| Warmup duration | 5–15 minutes typical |
| Cache folder | Documents\My Games\Rainbow Six – Siege |
| Frame cap sweet spot | 141 fps for 144 Hz panels |
The short version
- Monitor GPU temperature during warmup; sustained drops at 80–85 °C or higher point to throttling
- Watch VRAM and system RAM climb over multiple rounds to spot a memory leak
- Delete the shader cache folder and driver cache if FPS drops coincide with brief freezes
- Reapply thermal paste and clean dust when the GPU idles above 50 °C
- Cap frame rate to 141 fps to reduce heat buildup during warmup and long sessions
Why FPS drops after warmup in Rainbow Six Siege
Rainbow Six Siege runs fast in the menu and the first round, then frame rate collapses ten minutes later. That delay is the signature of a component hitting a limit it only reaches under load. The GPU heats up during warmup, VRAM or system RAM fills with assets the game never releases, or the driver recompiles shaders mid-match because the cache is corrupt.
Warmup is every action before the FPS drops: menu time, operator selection, drone phase and the first round or two. By the time you notice the stutter, the GPU may already be throttling at 83 °C, VRAM may be at 7.8 GB on a card with 8 GB total, or the shader cache may be rebuilding on every map load. Each cause has a different fix, so guessing wastes time.
The three checks below run in order of speed. Temperature takes thirty seconds to confirm. Memory leaks need two rounds. Shader and driver conflicts require a clean and retest. Start with the fastest check and stop when you find the culprit.
Most warmup FPS drops trace to thermal throttling on cards with old paste or dust in the heatsink. VRAM leaks are less common but show up after driver updates or when texture streaming is set to ultra. Shader stutter appears as brief freezes rather than a smooth slide, and it usually pairs with a corrupted cache after a patch. There is more on fps stutter sudden in a separate guide.
Check 1: Test if temperature is causing FPS drops
Open MSI Afterburner or HWiNFO64 and enable the in-game overlay for GPU temperature, GPU clock speed and fan speed. Launch Siege, play warmup and one full round while watching the overlay. If the GPU climbs past 80 °C and the clock speed drops by more than 100 MHz from its starting value, the card is throttling to protect itself.
Modern Nvidia and AMD cards throttle in steps. A GTX 1070 might run at 1,900 MHz at 75 °C, drop to 1,800 MHz at 82 °C, then fall to 1,650 MHz at 85 °C. Each drop costs you ten to twenty frames. The FPS loss is gradual over five to ten minutes, which matches the warmup window most players describe.
Check idle temperature next. Close Siege and let the GPU cool for five minutes, then note the reading. Idle above 50 °C in a room at 22 °C suggests old thermal paste or a dust-clogged heatsink. Idle below 40 °C with a load spike to 85 °C means the cooler is working but the case airflow is poor or the fan curve is too gentle. There is more on key fixes for roblox lag beyond internet speed in a separate guide.
The fix depends on the idle number. High idle needs new paste and a heatsink clean. Normal idle with high load needs a more aggressive fan curve in Afterburner, a case fan pointed at the GPU or an fps cap to reduce heat. Set the in-game frame rate limit to 141 fps if you have a 144 Hz monitor. Uncapped frames push the card harder than you need, and the extra heat builds during warmup.
- Install MSI Afterburner or HWiNFO64 and enable the overlay for GPU temp, clock and fan speed.
- Launch Siege, play warmup and one ranked or unranked match while monitoring the overlay.
- Note the temperature when FPS drops and compare it to the clock speed at that moment.
- Close Siege, wait five minutes and record the idle GPU temperature.
- If idle is above 50 °C or load is above 82 °C with a clock drop, reapply thermal paste and clean the heatsink.
- If idle is normal but load is high, raise the fan curve or cap frame rate to 141 fps.
Check 2: Spot memory or resource leaks causing FPS loss
Memory leaks fill VRAM or system RAM over time, forcing the game to page textures in and out or stutter while searching for free space. Open Task Manager on a second monitor or run GPU-Z in the background with logging enabled. Note VRAM use and system RAM use before launching Siege, then check again after warmup, after round one and after round three.
At 1080p on high settings, Siege should use 4–6 GB of VRAM and 8–10 GB of system RAM during a match. If VRAM climbs from 5 GB at menu to 7.5 GB after warmup and keeps rising, the game is leaking textures. System RAM climbing from 9 GB to 14 GB over three rounds points to a similar leak on the CPU side. Both cause stuttering that worsens over time. It helps to understand packet loss every few minutes rainbow six siege before going further.
Texture streaming quality set to ultra is the most common trigger. It preloads textures for every operator and map variation, filling VRAM faster than the game can release old assets. Lower it to high and restart Siege. If VRAM use stabilizes below 6.5 GB after warmup and stays flat, that was the cause.
Driver updates sometimes introduce leaks that the game cannot fix. Roll back to the previous stable driver if VRAM use climbs on every map load and lowering texture streaming does not help. Nvidia's 546.33 and AMD's 23.11.1 were the last known-stable drivers for Siege as of late 2023; check Reddit or the Siege subreddit for reports on newer versions before updating.
- VRAM climbing above 7 GB on an 8 GB card after warmup, with further rises each round
- System RAM use growing from 9 GB to 13+ GB over three matches without closing the game
- FPS drops that worsen with each map change rather than stabilizing after the first round
- Stutter or hitching every twenty to thirty seconds once VRAM is near capacity
Check 3: Driver and shader cache conflicts causing delayed drops
Shader cache corruption shows up as brief freezes rather than a smooth FPS drop. The game recompiles shaders for lighting, materials or effects mid-match, which costs fifty to two hundred milliseconds each time. Over ten minutes the freezes pile up and frame rate falls from 144 fps to 80 fps with spikes down to 40 fps every few seconds. It helps to understand stutters in hot drops pubg before going further.
Navigate to Documents\My Games\Rainbow Six – Siege and delete the entire folder. This removes cached settings, shader precompiles and any corrupted binaries the game wrote during a patch. Launch Siege and let it rebuild the cache during warmup. If FPS is smooth after warmup and the brief freezes are gone, the cache was the problem.
Driver shader caches live in a separate folder. For Nvidia, open C:\ProgramData\NVIDIA Corporation\NV_Cache and delete everything inside. For AMD, clear C:\Users\[YourName]\AppData\Local\AMD\DxCache and GLCache. Restart the PC, then launch Siege. The first match will stutter while the driver rebuilds shaders, but subsequent matches should be stable.
Software conflicts are harder to pin down. RGB control software, capture tools like OBS running in the background and some anti-cheat overlays inject into Siege and cause sporadic frame drops. Close everything except Steam or Uplay, then test warmup again. If FPS is stable, re-enable one program at a time until the drops return. Razer Synapse and Corsair iCUE are frequent offenders; disable their overlays or in-game integrations in the software settings. There is more on lol fps drops teamfights laptop in a separate guide.
| Cache type | Path | When to clear |
|---|---|---|
| Siege shader cache | Documents\My Games\Rainbow Six – Siege | After every major patch or if freezes appear mid-match |
| Nvidia driver cache | C:\ProgramData\NVIDIA Corporation\NV_Cache | After driver updates or if stutter persists after game cache clear |
| AMD driver cache | C:\Users\[YourName]\AppData\Local\AMD\DxCache and GLCache | After driver updates or when frame time spikes with no thermal cause |
What the monitoring numbers mean and how to act on them
A thermal throttle shows as GPU temperature above 82 °C paired with a clock speed drop of 100 MHz or more from the starting value. The frame rate slides from 144 fps at menu to 90 fps after warmup, then holds steady or drops further if the temperature keeps climbing. The fix is cooling: new paste, a heatsink clean, a steeper fan curve or an fps cap.
A memory leak shows as VRAM or system RAM climbing by 1 GB or more from menu to the end of round three, with FPS drops that worsen over time rather than stabilizing. Lower texture streaming quality, close background programs that use GPU memory and update or roll back the graphics driver. If the leak persists, reinstall Siege after clearing the shader cache.
Shader stutter shows as brief freezes of 50–200 ms with frame time spikes in the overlay, rather than a smooth drop in average FPS. Temperature and memory use stay flat. Clear the game cache, the driver cache and test with all background software closed. If it still happens, the driver is incompatible; roll back to a stable version or wait for a patch. Before you commit to anything, it is worth looking at how to stop rocket league lag.
When two causes overlap, fix the one with the clearest signal first. Thermal throttling at 85 °C will mask a small memory leak, because the FPS is already low. Drop the temperature below 80 °C, then retest for leaks. A shader cache issue usually resolves in one attempt; if clearing the caches does not work, it is not the cache.
When the checks show nothing wrong but FPS still drops
Temperature under 78 °C, VRAM flat at 5.2 GB, no shader freezes and FPS still falls after warmup means the bottleneck is outside the GPU or the game. Check CPU usage in Task Manager during a match. If one core sits at 95–100% while the others idle below 60%, Siege is CPU-bound and the warmup load pushes that core past its limit. Lower texture streaming to medium and disable temporal filtering to shift work back to the GPU.
Background Windows processes sometimes wake up ten minutes after boot and steal CPU time. Open Task Manager, sort by CPU and look for Windows Update, Defender scans or disk indexing during warmup. Pause Windows Update, exclude Siege's install folder from Defender real-time scans and disable search indexing on the drive where Siege lives. Retest warmup with those services quiet.
Server-side lag looks like FPS drops but shows up as high ping or packet loss in the Siege scoreboard. If your frame rate counter says 120 fps but the game feels like 60 fps, press F10 to see network stats. Ping above 60 ms or packet loss above 1% during warmup suggests the route to the server is congested. Wired Ethernet fixes most cases; if you are already wired, a route optimizer like GearUP Booster can find a faster path to the Siege servers and lower ping during peak hours.
A full reinstall is the last step, not the first. Only try it after you have cleared caches, updated drivers, tested thermals and ruled out background software. If none of the checks show a cause and FPS drops persist across multiple sessions, back up your settings and uninstall Siege through Steam or Uplay. Delete the Documents\My Games\Rainbow Six – Siege folder manually, restart the PC and reinstall. Test warmup immediately after install, before adding any background software back.
- CPU usage: one core at 95%+ while others idle, with frame time spikes matching the busy core
- Background services: Windows Update, Defender or disk indexing active during warmup in Task Manager
- Network stats: ping above 60 ms or packet loss above 1% shown by pressing F10 in-match
- Persistence: drops happen every session at the same point in warmup, ruling out one-off conflicts
Questions people still ask
Why does FPS drop only in ranked warmup and not casual?
Ranked warmup runs for a fixed duration and lets every player load operators and gadgets simultaneously, which spikes VRAM and GPU load. Casual warmup is shorter and fewer players pick complex operators, so the GPU may not reach throttle temperature or fill VRAM before the round starts. The underlying cause is the same; ranked just reveals it faster.
Will lowering graphics settings stop warmup FPS drops?
Only if the drops are caused by VRAM filling up or the GPU hitting thermal limits. Lowering texture quality from ultra to high cuts VRAM use by 1–2 GB, and reducing shadow quality lowers GPU temperature by 3–5 °C. If the cause is a shader cache conflict or CPU bottleneck, graphics settings will not help.
Can I just cap FPS to 60 instead of fixing the root cause?
Yes, but you will still have input lag and frame time spikes if the cause is thermal throttling or a memory leak. Capping FPS lowers the symptom; it does not stop the GPU from throttling or VRAM from leaking. Fix the cause first, then cap frame rate to 141 fps to prevent the problem returning during long sessions.
How often should I clear Siege's shader cache?
After every major seasonal patch and whenever you update graphics drivers. Siege rebuilds shaders on the first launch after a clear, which takes two to three minutes, but the game runs smoother afterward. If you never see brief freezes or hitching, you do not need to clear it.
Does disabling V-Sync help with warmup FPS drops?
No. V-Sync caps frame rate to your monitor's refresh rate and adds a small amount of input lag, but it does not cause warmup FPS drops. If your frame rate is already below the refresh rate because of throttling or a memory leak, disabling V-Sync changes nothing. Turn it off for lower input lag, not to fix drops.