What the BIOS actually does with your RAM profile
An XMP or EXPO profile is a stored preset. Intel describes XMP profiles as preset combinations of speed, timing and voltage that you enable in the BIOS. The module holds the numbers. The motherboard firmware decides whether and how to apply them.
Khan's article describes each profile as a request the board may not handle well. It says DDR5 modules can hold up to five profiles: three vendor-rated and two user-writable. Intel's own XMP page backs this up. It says XMP 3.0 for DDR5 supports up to 5 profiles (3-vendor and 2-rewriteable). Kingston's DDR5 guidance says its Renegade-class modules ship with a most-aggressive Profile 1, which is the advertised speed, and a less aggressive Profile 2. Some DDR5 XMP parts add a third.
Intel is also candid that XMP is memory overclocking. Its XMP page says that using it beyond the given specifications may void the processor warranty. So an advertised "rated speed" is a vendor-tested target, not something the CPU and board are obliged to deliver.
Why memory training matters
Training is the startup routine where the firmware calibrates the memory signal path. Kingston says DDR5 training happens on first boot, after a memory configuration change, or after a firmware update. It adds that some DDR5 PCs can take several minutes, so a blank screen isn't necessarily a hang.
Khan goes further. He says old training code can set timing offsets incorrectly, drop speeds, or leave too little margin, so the memory is unstable. That mechanism is plausible. Still, the vendor documentation I reviewed doesn't confirm it for any particular board, so treat it as Khan's explanation. The board maker's release notes are the authority for a specific fix.
The scenario he highlights is common: a board that sat in a warehouse with launch-era firmware, paired with a newer, denser kit it has never seen. Kingston's FAQ points the same way. It says first-generation DDR5 platforms need a BIOS update from the board maker to support 24Gbit-based modules.
Evidence that BIOS updates do target memory
Board makers regularly write memory fixes into their release notes. Wikipedia's AGESA table lists AM5 releases with notes such as improved memory compatibility. One entry is 1.2.0.3a Patch A, which improves single and dual rank memory compatibility on X870 and B850 boards. More recently, the table lists 1.3.0.1c as improving CXMT memory compatibility, dated July 2026. These are community-maintained summaries, so confirm the details against your board's own notes.
MemTest86's troubleshooting page also says RAM incompatibility issues can sometimes be fixed with a BIOS update. Kingston's FURY guidance recommends having the latest BIOS before setting overclock timings.
One caution from this year's news: a BIOS update won't necessarily unlock new memory features. TechPowerUp reported that ASUS and MSI added EXPO-ULL support to some X670E boards. The same coverage notes that EXPO Ultra Low Latency needs DDR5 modules with a ULL profile in the SPD, and existing EXPO kits can't be upgraded through a BIOS update. Firmware changes how a board treats memory. It can't rewrite what the memory is.
How to tell whether your BIOS is the bottleneck
Follow this order. It's more cautious than the original article's flow.
- Record your configuration. Note the CPU, exact motherboard model and revision, memory kit part number, module count, and current BIOS version. You can find the BIOS version in System Information on Windows.
- Confirm the profile is on. Check the BIOS memory profile setting. On ASUS boards, ASUS says Intel platforms use XMP and AMD AM5 uses EXPO. Cross-pairing kits uses a setting labeled DOCP. ASUS also warns that menu names vary by board and BIOS version.
- Check what Windows reports. ASUS says you can see memory speed in Task Manager under Performance, then Memory. Compare this with the profile you expected.
- Check slot placement. Use the slots your manual recommends. ASUS's troubleshooting advice also says to use matched modules rather than mixing.
- Test default versus profile. Run MemTest86 at default settings, then with the profile. Errors that appear only under the profile suggest the profile is too aggressive for your configuration. They don't prove the BIOS is old. MemTest86 itself notes that not all errors it reports are due to bad memory. The CPU, caches and motherboard are all implicitly under test.
- Check the QVL and release notes. Look up your exact kit on the board's qualified vendor list. Then read the BIOS release notes for memory-related fixes. A QVL is a list of tested kits. An unlisted kit isn't automatically incompatible.
- Rule out defaults failing. Kingston's guidance says that if memory fails even at default settings, you should contact support. A BIOS update shouldn't be assumed to fix that.
Updating safely
A BIOS flash carries real risk. The general advice holds up: use stable power, read the model-specific instructions, and don't interrupt the process.
- Expect your settings to reset. The original article says an update wipes custom settings, including your profile. That is commonly true, so note your changes and re-enable XMP or EXPO afterward.
- Plan for BitLocker. One 2026 guide recommends saving BitLocker recovery information before firmware changes. Firmware updates can trigger recovery prompts on some systems, so having the key handy is cheap insurance.
- Follow your vendor's method. Khan recommends a USB drive over internet-based updating. I wouldn't call that a universal rule. Use the method your board maker documents for your exact model, whether that's an in-BIOS flash tool or a feature like ASUS USB BIOS FlashBack on supported boards.
- Allow time for retraining. After the update, the first boot may take longer because memory training runs again. Don't power off during that blank-screen pause.
- Don't update just because a newer version exists. If the release notes show nothing relevant and your system is stable, you may not need it. Security fixes can be a good reason to update anyway, as Khan notes.
Claims to treat carefully
Dual-channel and "more than two kits." The article says using more than two kits can split dual-channel bandwidth. That conflates channels with modules. Kingston's guidance is narrower and more useful. Mixing kits, even of the same part number, may result in degraded performance, instability, or incompatibility. Buy a single kit of the capacity you need.
The 7400 MT/s example. Khan says AGESA 1.0.0.7b expanded AM5 support to kits up to 7400 MT/s. I couldn't confirm that figure from AMD or a board maker. Treat it as the author's historical example, not a promise for any kit or board. Your CPU's memory controller sets the limit. Khan acknowledges that a BIOS update cannot raise the CPU's memory controller limit. I also couldn't find a primary source establishing Intel's FSP as the exact parallel path, though the AGESA and FSP comparison is a fair general description of how firmware code reaches board makers.
Shorter boot, fewer crashes, better four-DIMM support. These are plausible BIOS-update outcomes. Individual boards document them differently, so rely on your board's release notes.
Bottom line
A newer BIOS is a reasonable early step when an XMP or EXPO profile is missing, greyed out, or unstable, particularly on a new board with an older firmware and a newer kit. Confirm your configuration, test at defaults, read the release notes for memory fixes, and flash only with your vendor's instructions. If the kit still fails at the profile, drop to a less aggressive profile or a lower speed. The CPU, board and kit combination sets the ceiling, and a BIOS can only help you reach it.