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BIOS tweaks

Firmware settings, including hidden ones your BIOS menu never shows, written via SCEWIN with no manual UEFI poking.

BIOS tweaks, including hidden settings your firmware menu never shows, written straight to firmware via SCEWIN with no manual UEFI poking. Pick your CPU vendor when prompted, toggle the rows you want, click Apply, and reboot. Writes only take effect after the next BIOS pass, and anything your motherboard doesn't expose stays greyed out.

Compatibility

Most systems are compatible with BIOS tweaks. If you built your own PC, you're almost certainly fine. The exceptions are laptops and prebuilt OEM PCs (Dell, HP, Lenovo), whose firmware is locked down by the OEM and hides most of these options. If a Setup Question isn't exposed by your firmware, the row stays greyed out and clicking Apply silently skips it.

Two motherboard brands need an extra step before BIOS tweaks can work. ASUS and ASRock ship with runtime-variable protection turned on, which blocks SCEWIN from writing to firmware, but the fix differs by vendor. This applies to ASUS (Z790+, B760+, H770+ | X670+, B650+, A620+) and ASRock (Z590+, B560+, H510+ | B550, X670+, B650+, A620+) boards.

1. Both: in Device Manager (Win+R → devmgmt.msc), under Other devices, make sure every PCI Device is enabled.

2. ASUS: in BIOS, enable Publish HII Resources under the Tool menu, then go to Advanced → UEFI Variables Protection and set Password protection of Runtime Variables to Disabled. Save & Exit. It's a quick, non-destructive toggle, and that's all ASUS boards need.

3. ASRock: the same Password protection of Runtime Variables setting must be disabled, but ASRock hides it from the BIOS menu and there is no reliable way to turn it off in firmware. The only known route is modding the BIOS image and flashing it with a hardware programmer, which risks bricking the board and is strictly for advanced users at their own risk. On an affected ASRock board, treat the BIOS tweaks as unavailable and apply the equivalent settings from your board's normal, visible BIOS menu instead.

Before buying Elite for BIOS tweaks specifically: open the BIOS tab in the free version, let it initialize SCEWIN and detect your motherboard, and see how many rows light up vs. how many are greyed out. That's exactly what you'd be able to apply once you upgrade, with no surprises.
Using the Akros anti-cheat (FACEIT)? Writing BIOS settings needs a low-level driver, and while the Akros anti-cheat is loaded, it blocks that driver. If you're affected, the BIOS tab fails to initialize with a “couldn't load driver” error before you can toggle anything. Right-click the Akros / FACEIT anti-cheat icon in your system tray and choose Disable driver, then reopen the BIOS tab. Once your tweaks are applied, re-enable it before playing FACEIT again.
Your BIOS export helps us support more boards. Opening the BIOS tab sends us the settings export SCEWIN just read, along with your CPU, motherboard model, and BIOS version. We use these exports to find and test new BIOS tweaks. You can turn this off under Privacy in the app's Account tab.

Before applying

Test the power-saving rows before keeping them. Disabling CPU and chipset power-saving features doesn't always raise performance. On a system with marginal cooling or existing instability it can make throttling or crashes worse. Apply, benchmark, and revert any that don't actually help.
These are real performance wins, not fine print. The virtualization rows (Intel VT-x / VT-d, AMD SVM / IOMMU) remove virtualization overhead and cut memory-access latency, and the security rows (Intel SGX, AMD memory encryption) free reserved RAM and skip per-access work. The trade-off is security plus the anti-cheat requirements below, so weigh each row on its own rather than assuming it isn't worth applying.

C-states

Disabling C-states used to be the first tweak everyone applied, back when most tuned PCs ran a fixed all-core overclock: every core sat at the same speed, so keeping them awake only removed wake-up delay. At stock settings modern CPUs work differently. They boost the busy cores higher while idle cores sleep, so keeping every core awake can cost the top single-core boost steps. No published benchmark shows an FPS gain from disabling them on current CPUs, so the app asks before turning these rows on and tailors the advice to your CPU:

  • Intel 13th and 14th gen Core: not recommended. Intel lists disabling C-states among the settings that raise the risk of instability on these chips.
  • Other Intel CPUs, including Core Ultra (Arrow Lake): optional. Expect to lose the top single-core boost steps, mostly on i7, i9 and Ultra 7/9 chips.
  • AMD Ryzen: the app splits this into two rows. Fabric C-states off is AMD's own low-latency recommendation. Core C-states off can lower single-core boost (the 5800X3D and some early Ryzen 7000 BIOSes lose their top boost step entirely), and AMD recommends leaving it on.
  • Fixed all-core overclock: turning C-states off is fine, because boost doesn't depend on idle cores.

If you do turn them off, benchmark before and after and keep them off only if your games actually run better.

Resizable BAR

Resizable BAR (AMD calls it Smart Access Memory) lets the CPU reach all of the graphics card's memory at once instead of in 256 MB windows. It is one of the few BIOS settings with large, measured gains: Intel Arc cards lose around a quarter of their performance without it, and AMD Radeon RX 6000 and newer gain around 4 to 5% on average. On NVIDIA cards the driver only turns it on in games where NVIDIA measured a gain, so the difference there is small.

The row writes every setting Resizable BAR needs in one go: Above 4G Decoding, the Resizable BAR switch itself, and CSM (legacy boot support) off, because the switch does nothing while CSM is on. The app only offers it when:

  • Windows booted in UEFI mode. Turning CSM off is then safe. If Windows booted in legacy mode, the system disk has to be converted to GPT first (Microsoft's mbr2gpt tool), which the app doesn't do for you.
  • Your graphics card supports it: NVIDIA RTX 30 series or newer, AMD Radeon RX 6000 series or newer, or Intel Arc.

If you use BitLocker, keep your recovery key at hand before applying, because firmware changes can make Windows ask for it on the next boot.

Check that Resizable BAR is actually enabled

The toggle in the app alone isn't enough as your GPU's own firmware (its vBIOS) has to support Resizable BAR too. After you restart, open the BIOS tab again. The app reads the memory window your card actually got at boot and shows either Active or a note that the card isn't using it yet.

If it stays off with the BIOS setting on, the card most likely needs a vBIOS update. This is common on RTX 30 cards made before mid-2021, which shipped before NVIDIA added Resizable BAR support. To fix it you need to update your vBIOS:

  • MSI: MSI Center, Live Update, Advanced mode.
  • Other brands (ASUS, Gigabyte, EVGA, Zotac and others): the vBIOS or firmware section of your exact card model's support page, or the brand's own update app.

Keep the PC on and plugged in while the update runs, then restart and check again.

XMP and EXPO memory profiles

Memory runs at a slow default speed until its profile is switched on in BIOS, and roughly a quarter to a third of the systems we see never switch it on. XMP (Intel and most kits) and EXPO (AMD Ryzen 7000 and 9000) load the speed and timings printed on the kit. Going from the default DDR5-4800 to an EXPO 6000 kit has measured around 10% more average FPS and 20% better 1% lows on a Ryzen 7 7800X3D. On AM4 the default speed also halves the Infinity Fabric clock, so the gain there is larger still.

The app always picks the first profile. It holds the row back, with an explanation, when:

  • Ryzen 7000/9000 on a BIOS from before June 2023. Early AM5 firmware let EXPO push SoC voltage high enough to damage the CPU. Update the BIOS first; every current release caps it.
  • Intel 13th or 14th gen desktop CPUs on microcode older than 0x12B. Update the BIOS first; the newer microcode fixes the voltage behaviour behind the instability those chips had.

Some boards can't be set from Windows: ASUS AM4 boards (the option is hidden from the tool; enable D.O.C.P. in the BIOS menu instead), and ASUS AM5 and ASRock AMD boards, whose memory menu isn't exposed. On MSI AM5 boards the row sets EXPO; a kit with only an XMP profile needs A-XMP set in the BIOS menu.

If the PC doesn't start after enabling XMP or EXPO: first give it a few minutes, because the first boot after turning it on retrains the memory and can sit on a black screen for a while, especially on Ryzen 7000 and 9000. Most motherboards then fall back to safe memory settings on their own after about three failed attempts. If yours keeps failing, clear CMOS: press the Clear CMOS button on the rear I/O if your board has one, or short the two CLR_CMOS pins with the PC off and unplugged (your manual shows where), or remove the coin battery for a few minutes. That resets BIOS settings to default, so apply your tweaks again afterwards. Kits of four sticks are the most likely to fail at their rated speed.

Kernel-level anti-cheat

Playing games with kernel-level anti-cheat? The virtualization rows can stop a game launching, kick you mid-match, or flag your account. Competitive Fortnite and FACEIT require IO virtualization (Intel VT-d, AMD IOMMU) left on, because it backs Kernel DMA Protection. Valorant (Vanguard) and FACEIT also require Memory Integrity (HVCI), which can't run without CPU virtualization (Intel VT-x, AMD SVM). On Intel the single “Disable virtualization” row turns off VT-x and VT-d together, so it hits both; on AMD the SVM and IOMMU rows are separate. The app flags each affected row with a red warning sign. If a game stops working after applying, re-enable the row and click Apply again.

The Windows-side half of this, HVCI, VBS and the CPU side-channel mitigations, is on the Mitigations page.

The tweaks, by CPU vendor

The catalog only shows tweaks for your detected CPU vendor (Intel or AMD). Both lists are collapsed below, so expand the one matching your CPU.

Intel BIOS tweaks

Intel graphics & memory

  • Enable Resizable BAR lets the CPU reach all of the graphics card's memory at once. See Resizable BAR for when it's offered.
  • Enable XMP memory profile runs your memory at the speed and timings printed on the kit instead of the slow default. See XMP and EXPO.

Intel power-saving features

  • Disable C-states keeps CPU cores out of deep idle so they're always ready for work, removing wake-up stalls when bursty work hits. See C-states first: it can cost single-core boost, and it isn't recommended on 13th and 14th gen Core CPUs.
  • Disable PCIe clock gating stops the PCIe controller gating its clock during idle, removing wake-up cost on every device access.
  • Disable Energy Efficient P-state removes the BIOS hint that biases Windows toward lower-power P-states, so the CPU ramps up faster under load.
  • Disable Energy Efficient Turbo stops the CPU trimming its turbo frequency when it judges the work to be memory-bound, so boost stays steady under load.
  • Disable ASPM turns off PCIe Active State Power Management. GPU, NVMe and NIC links stay permanently active instead of sleeping during idle.
  • Disable LTR turns off Latency Tolerance Reporting, the budget devices use to enable deep PCIe L1 sub-states. Leaving it off keeps links out of their slowest-to-wake sleep, the same path as ASPM.
  • Disable Race To Halt (RTH) turns off the strategy of finishing work as fast as possible just to enter idle quicker for power savings.
  • Disable OBFF turns off Optimized Buffer Flush/Fill. Devices stop deferring traffic and interrupts into power-aligned idle windows, so they're serviced promptly instead.

Intel performance

  • Disable spread spectrum stops the BIOS intentionally jittering BCLK and PCIe clocks to spread EMI, giving tighter clocks at the cost of slightly more interference.
  • Disable XHCI hand-off stops the BIOS owning USB controllers during boot so Windows takes them directly, avoiding the BIOS's slower USB stack.

Intel security

  • Disable Software Guard Extensions turns off Intel SGX, freeing the reserved RAM region. SGX is rarely used outside select DRM and security tools.

Intel virtualization

  • Disable virtualization turns off both VT-x and VT-d, removing virtualization overhead and lowering memory-access latency. Leave this on if you play Valorant or competitive Fortnite. Valorant's Vanguard needs VT-x (its required Memory Integrity/HVCI can't run without it) and competitive Fortnite requires VT-d enabled.

Intel miscellaneous

  • Enable PCI delay optimization tightens BIOS-side PCIe device-init delays for a slightly faster boot.
AMD BIOS tweaks

AMD graphics & memory

  • Enable Resizable BAR (Smart Access Memory) lets the CPU reach all of the graphics card's memory at once. See Resizable BAR for when it's offered.
  • Enable XMP memory profile (AM4) and Enable EXPO memory profile (AM5) run your memory at the speed and timings printed on the kit. On AM4 this also raises the Infinity Fabric clock. See XMP and EXPO.

AMD power-saving features

  • Disable fabric C-states keeps the Infinity Fabric out of its low-power state, so memory and PCIe traffic never waits for the fabric to wake. This is AMD's own recommendation for latency-sensitive work.
  • Disable core C-states keeps CPU cores out of deep idle so they're always ready for work, removing wake-up stalls when bursty work hits. See C-states first: it can lower single-core boost.
  • Disable chipset power-saving features turns off chipset-level power-state negotiations across PCIe and the SoC fabric.
  • Disable AB clock gating turns off clock gating on the SoC's Advanced Bus fabric, keeping internal data paths always-on.
  • Disable ECO mode turns off AMD's BIOS-level lower-TDP profile so the CPU runs at its full power budget.
  • Disable AMD Cool'n'Quiet turns off Cool'n'Quiet, AMD's CPU power-saving feature, so the CPU runs at a higher floor frequency.

AMD performance

  • Disable spread spectrum stops the BIOS intentionally jittering clocks to spread EMI, giving tighter clocks at the cost of slightly more interference.
  • Disable XHCI hand-off stops the BIOS owning USB controllers during boot so Windows takes them directly.
  • Lock the SoC fabric at full speed turns on SoC/Uncore OC Mode, which forces the Infinity Fabric, memory and other SoC components “to run at their maximum specified frequency at all times”, so memory and PCIe traffic never waits for them to ramp up. On AM4 it also sets APBDIS to 1 so the fixed SoC P0 state takes effect. It costs some idle power, and on a few boards it disables sleep (S3).

AMD security

  • Disable memory encryption turns off transparent memory encryption (TSME / SMEE), saving the encrypt and decrypt cycle on every RAM access.

AMD virtualization

  • Disable SVM turns off Secure Virtual Machine (AMD's VT-x equivalent), removing virtualization overhead and lowering memory-access latency. Leave this on if you play Valorant. Its Vanguard requires Memory Integrity (HVCI), which can't run without SVM.
  • Disable IOMMU turns off AMD's IO Memory Management Unit (the VT-d equivalent), removing IO virtualization overhead. Leave this on if you play competitive Fortnite, FACEIT or Valorant. Fortnite and FACEIT require IOMMU enabled, and Valorant's Vanguard can refuse to launch without it on AMD systems.

The Windows-side power settings these pair with, ASPM in the power plan, USB and NVMe idle, are on the Power tab.