This article covers インテル Core i9-9900K デスクトッププロセッサー 8コア 最大5.0GHz アンロック LGA1151 300シリーズ 95W (BX806849900K).

Overview

The Intel Core i9-9900K is a flagship desktop processor from the 9th Gen Coffee Lake Refresh family, launched in late 2018. With 8 cores and 16 threads, a maximum boost clock of 5.0 GHz, and an unlocked multiplier for overclocking, it was the ultimate gaming CPU of its era. It uses the LGA1151 socket and pairs with Intel 300-series chipsets like Z390. Despite its age, the 9900K remains a capable performer for gaming and productivity, though it’s now more of a budget high-end option in the second-hand market.

Compatibility Guide

The Core i9-9900K fits any motherboard with an LGA1151 socket and an Intel 300-series chipset (Z390, Z370, H370, B365, H310). Note that Z370 boards may require a BIOS update to support this CPU. It supports dual-channel DDR4 memory up to 2666 MHz officially, but many Z390 boards allow faster XMP profiles. The CPU requires an 8-pin EPS power connector, and a full system with a high-end GPU should have a power supply of at least 850W. PCIe 3.0 is the maximum supported, so you won’t get PCIe 4.0 or 5.0 benefits. Storage interfaces include SATA 6Gbps and NVMe via M.2 slots (PCIe 3.0 x4).

Product Info

Released in October 2018, the 9900K originally sold for around $500 USD. Today, new stock is scarce; lists it for about ¥78,416 (~$540). The processor comes with a 3-year Intel warranty if purchased new. It is built on the 14nm++ process, has 16MB of L3 cache, and includes Intel UHD Graphics 630. Market positioning: high-end at launch, now a legacy enthusiast CPU with strong single-threaded performance but outdated platform features.

Best Use Cases

  1. Legacy gaming PC upgrade: If you already have a Z370 or Z390 board, dropping in a 9900K can give you a significant performance boost without replacing the motherboard and RAM. This is cost-effective for those on a tight budget. 2. High-refresh 1080p/1440p gaming: The 9900K's strong per-core performance still delivers excellent frame rates in most modern games, especially those not heavily reliant on many threads. However, for CPU-bound AAA titles at ultra settings, newer CPUs like the i5-13400F or Ryzen 5 7600 outperform it. 3. Budget enthusiast build: Buying a used 9900K (around $200-300) paired with a used Z390 board can be a fun, affordable way to build a powerful PC that handles most tasks. Just be aware of the platform’s limitations. 4. Windows 11 compatibility for older PCs: If you have a compatible LGA1151 board, upgrading to a 9900K can enable Windows 11 support without a full platform overhaul. But consider if the upgrade cost justifies the limited future.

Things to Consider

The biggest drawback is the dead-end platform: LGA1151 has no upgrade path beyond the 9900K series. You also miss out on DDR5, PCIe 4.0/5.0, and modern connectivity features like USB4 or Thunderbolt 4. The 9900K runs hot under load (especially overclocked) and requires a robust cooler – a high-end air cooler or at least a 240mm AIO is recommended. Competing alternatives include the newer Intel Core i5-13400F (similar gaming performance, better multi-core, cheaper, supports DDR4 and DDR5) or AMD Ryzen 7 5700X (comparable multi-thread, lower power, but still on an older AM4 platform). The 9900K makes sense only if you already own a Z390 board or find a very cheap used combo. ## FAQ
Q: Can the Core i9-9900K run Windows 11? A: Yes, it supports TPM 2.0 and Secure Boot, meeting Windows 11 requirements. Note that Windows 10 will reach end-of-life in October 2025, so upgrading to Windows 11 is advisable. Q: What cooler is recommended for the 9900K? A: Due to its high TDP (95W) and thermal density, a high-end air cooler like the Noctua NH-D15 or a 240mm/280mm AIO liquid cooler ensures stable turbo/overclock performance. A stock cooler is not included and would be insufficient. Q: Is the 9900K still good for gaming in 2026? A: Yes, for many games it still provides excellent performance, especially at 1440p with a high-end GPU like the RTX 4070. However, in CPU-intensive titles like Cyberpunk 2077 or Starfield, newer CPUs will show a clear advantage. If you can get a good deal on a used 9900K + motherboard combo, it’s still a viable budget gaming option.

Product Disclosure (Amazon)

  • Manufacturer: インテル
  • Seller: Amazon US
  • Fulfilled by: Amazon US
  • ASIN: B089J731BX
  • Note: This article covers a manufacturer-made product based on Amazon listing details.