Intel explains what went wrong with its new Arrow Lake desktop CPUsAnd declares four out of five identified issues "solved".Image credit: Digital Foundry Blog by Will Judd Deputy Editor, Digital Foundry Published on Dec. 19, 2024 Intel's new Core Ultra 200-series desktop processors, codenamed Arrow Lake, launched to seriously underwhelming reviews back in October. Now the American firm has collated five issues that it says are to blame for the difference between its own performance expectations and what reviewers experienced, with four of the five problems described as being already resolved by BIOS, Windows or application updates, and further performance enhancements to arrive in January 2025. For context, our Core i9 285K and Core i5 245K review saw performance wins for the 285K against the outgoing 14900K in three titles - Crysis 3 Remastered, Dragon's Dogma 2 and Forza Horizon 5 - while the 14900K retained its crown in the other eight games we tested, often by extreme margins. Here are the five issues, their root cause and current status, quoted from Intel's release: Performance TopicRoot CauseStatusUnusual scheduling, high run-to-run variation, low single-threaded scores, intermittent ~1.5x increase in DRAM latency, performance lower on Windows 11 24H2 vs 23H2Intel mistimed deployment of OS power plan settings ("PPM"), which customises DVFS, core parking and C-states. This caused a 6-30% performance lossSolved in Windows 11 26100.2161 or newerIntel Application Performance Optimiser (APO) not demonstrating expected performance resultsMissing PPM places CPU into state where APO profiles cannot apply, select reviewer BIOSes additionally set APO to disabled by default. This caused a 2-14% performance loss on APO-profiled titlesSolved in Windows 11 26100.2161 or newerBSOD when launching Easy Anti-Cheat titles on Windows 11 24H2Known issue with Easy Anti-Cheat KMD and Windows 11 24H2, issue exacerbated by disabling Virtualisation-Based Security (VBS)Solved with new Easy Anti-Cheat driver distributed by EpicSelect performance settings misconfigured in some pre-release BIOSesConsistency of VIP performance settings not sufficiently checked by Intel, including ReBAR, Intel APO, compute ring frequency, IMC gear, sustained/transient power limits. This caused a 2-14% performance lossSolved in customer BIOSes now availableNew BIOS performance enhancementsFresh optimisations developed for upcoming BIOS updates, currently in validation by Intel and its partners, single digit performance enhancement estimated among a 35-game geomeanMotherboard BIOSes planned for January 2025The table makes for interesting reading, and Intel's community blog on the subject goes into further detail on each identified issue too. In it, Intel promises "a complete performance digest, inclusive of the January BIOSes" at CES early next year, so we should get a better idea of exactly the performance differentials we should expect with all five fixes applied. We also saw extremely poor performance in Cyberpunk 2077 in particular, and that seems to have been solved in game update 2.2 if the patch notes are to be believed. If you are one of the vanishingly small number of people to be running a Core i5 245K, Core i7 265K or Core i9 285K system, then you've probably already updated to the latest Windows and BIOS versions, but it's worth doing so now if you haven't - and again in mid January when further BIOS updates are made available - to ensure that your system is delivering maximum performance. Intel says that the January BIOSes can be "identified with Intel microcode version 0x114 and Intel CSME Firmware Kit 19.0.0.1854v2.2 (or newer)." We'll look to retest the Core i9 285K and Core i5 245K once these January BIOS updates are available, as we did see much worse performance than we expected and it would be nice to see what these proccessors are truly capable of. We're expecting to hear more from Intel at that time - as well as rivals AMD and Nvidia - so stay tuned for our reports from CES in the new year.