Intel Core i9-9900K Review 187

Intel Core i9-9900K Review

(187 User Comments) »

Value and Conclusion

  • The Core i9-9900K is currently listed on Amazon for $530. For some reason, the Newegg price, which we usually use, is $580.
  • 8 cores and 16 threads
  • 5 GHz boost
  • Trades blows with more expensive Core i9-7900X
  • Unlocked multiplier
  • Soldered IHS
  • Works on existing LGA1151 platform, even with Z370 motherboards
  • Integrated graphics
  • Supports up to 128 GB memory
  • High price
  • Held back by power limits
  • Only small gaming performance improvements
  • No heatsink included
  • Weak integrated graphics
The new Intel Core i9-9900K finally puts eight cores and 16 threads into the hands of gamers, consumers and enthusiasts. While still being built on Intel's 14 nanometer process, using the Coffee Lake architecture, the increased core counts ensure Intel once again achieves parity with AMD Ryzen when it comes to core counts. Intel's high IPC, paired with the 5 GHz boost clock of the i9-9900K, should yield excellent results.

CPU performance of the Core i9-9900K is good, especially in applications that scale with multiple cores. Here, the i9-9900K is really close and often beats the much more expensive Core i9-7900X, while happily working with dual-channel memory at lower overall platform cost. When averaged over our mix of low-threaded and multi-threaded apps, the performance increase over the Core i9-7900X is around 10%. Compared to the Core i7-8700K, last generation's flagship, the 9900K is 19% faster because of more cores at higher clocks. Against AMD's Ryzen 2700X, the performance increase is 20%, which is pretty impressive considering they both have eight cores and 16 threads.

A surprising result is that the Core i9-9900K matches the performance of AMD's 16-core / 32-thread Threadripper 2950X processor when averaged over our whole CPU test suite. This is highly application-dependent, though. Threadripper has the upper hand in multi-threaded applications, while the Core i9-9900K is considerably faster with lightly threaded software.

Intel's own marketing paraded the Core i9-9900K as the best processor for gamers. While that is technically true, the differences are rather slim in our own testing. For example, at 1080p resolution, with all games set to highest details, the difference between the i7-8700K and i9-9900K is just 2%. As you increase resolution, the bottleneck shifts more and more to the GPU, which is why even higher resolutions like 1440p or 4K see smaller increases. Even at the theoretical scenario of 720p, where the CPU is the bottleneck, the same 2% difference stands. Compared against AMD Ryzen processors, the differences are bigger, especially at 720p, where the 9900K is 17% ahead. As we increase resolution, that advantage does get smaller and smaller, though; 1080p sits at 8%, 1440p at 4%, and 4K at 2%.

Intel has finally revamped the heatspreader on all new Coffee Lake processors, which now uses solder instead of thermal paste, resulting in better heat transfer. This matters for overclocking because previously, the CPU temperature would shoot up quickly when overclocked with higher voltage, limiting the maximum clocks. I'm happy to report that thermal performance of the Core i9-9900K is much better and that temperatures change much more gradually than before. It's also easier to manage temperatures despite the increase from 6-core to 8-core. Our manual overclocking on air netted us 5.0 GHz on all cores, which was limited by heat. With a 240 mm all-in-one watercooler on the CPU, 5.1 GHz was no problem, 5.2 GHz was almost stable, and heat was never an issue.

Overclocking, while easy because of the unlocked multiplier, is slightly complicated by the 95 W TDP limit of the 9900K, which will automatically drop clocks when it senses too much power draw. For example, when set to 5 GHz all-core with some extra voltage, clocks will instantly drop to around 4 GHz as soon as you put a serious multi-core load on the CPU. To raise this limit, you'll have to adjust the power limit in BIOS or XTU—a first for Intel, but no problem as long as you are aware of it.

The same power-capping mechanism also limits the CPU's boost clocks, even when running completely at stock. Since the processor is specified to respect a 95 W TDP limit out of the box, highly-threaded, demanding apps will run into this 95 W limit quickly, and boost clocks will drop to stay within the 95 W power envelope. This means that even when you choose not to overclock your processor at all, increasing the "Turbo TDP Limit" beyond 95 W, in line with what your motherboard VRM and cooler can handle, will instantly result in higher performance for these applications. In our testing with Blender rendering, we could gain 15% performance just by upping the TDP limit, without any manual overclocking.

As expected, without any change in process or architecture, power consumption of the Core i9-9900K is similar to other Coffee Lake processors. This is indicated by our single-threaded power consumption numbers, where TDP limits don't play a role. Once you fully stress all cores, the power gets capped to 95 W, which is to ensure all existing motherboards work with this processor. At 95 W, with all cores active, the i9-9900K is actually the most energy efficient Intel processor we have ever tested; looks like Intel is operating it near its peak efficiency levels in this scenario.

With this launch, Intel also introduces a new chipset called Z390 (we posted several Z390 motherboard reviews today). The differences are slim: you get support for 10 Gbps USB 3.1 ports and integrated Wi-Fi 802.11ac. Both Z370 and Z390 support all 8th and 9th-gen Intel processors, with Z370 requiring a BIOS update for 9th gen. We are currently checking with Intel whether they offer some kind of CPU loaner program for BIOS updates, like AMD does, and will update here accordingly.

Priced at $530, the Core i9-9900K opens up completely new price regions for the LGA 1151 platform. Where previously the most expensive processor, Intel's 8700K, was $380, you're suddenly asked to spend over 40% more (for a 33% core count increase). When looking at performance, this price increase isn't justified in any way, except maybe if you compare it with Intel's HEDT platform, which was always expensive. AMD's Ryzen offerings are much more affordable and the clear winners when it comes to bang for the buck, which is amplified by Intel's recent price increases across the board (due to production capacity shortages). Especially when it comes to gaming, conscious allocation of funds can be key. Instead of spending a lot of money on a processor, you could go with a cheaper variant without much impact on FPS and spend the leftover money on a faster graphics card, giving you more actual FPS. On the other hand, obsolescence of processors is almost non-existent these days, so if you are looking for future-proofing, then Intel's latest Core i9 processors should be on your list; and then there are those who just want the fastest CPU to pair with their brand-new GeForce RTX 2080 Ti, no matter the cost, and that's the Intel Core i9-9900K.
Editor's Choice
Next Page »(187 User Comments)