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REVIEW: Intel Core i9-10900K

By Antony Leather. Posted

A couple of years ago, we were expecting Intel’s 10th-generation CPUs to sport a 10nm manufacturing process, but we’re still sat at 14nm and using the ageing Skylake-based architecture with minimal revisions.

Core counts have improved by a fraction of what AMD has managed too, rising from four to ten cores with the stack-topping Core i9-10900K we’re reviewing here, whereas AMD offers up to 16 cores on its mainstream desktop platform. On the plus side, the maximum boost clock of 5.3GHz will give it an edge over the AMD competition in some games.

What’s more, the Core i9-10900K’s price is similar to that of the Core i9-9900K when it launched 18 months ago, but with two extra cores and higher frequencies. With ten cores and 20 threads, the Core i9-10900K offers two more cores and four more threads than the Core i9-9900K, and the amount of L2 cache has also gone up accordingly.

Thanks to Intel’s Thermal Velocity Boost, which increases CPU frequency according to thermals and motherboard capabilities, the Core i9-10900K can also hit 5.3GHz across up to two cores at the same time, which is 600MHz higher than the top boost clock of any current AMD CPU.

The Core i9-10900K's die is 0.3mm thinner than that of its predecessor, but the heatspreader is thicker

This was a bit of an issue at launch, though, as motherboard manufacturers struggled to hit this frequency at all, and even when the chip did boost, just having a couple of low-key programs open in the background would see the frequency top out at 5.1 or 5.2GHz.

At stock speed, the all-core boost sat at around 4.9GHz, which is just short of the 5GHz all-core boost achieved by the Core i9-9900KS. It’s much faster than the 4.3GHz all-core boost we observed with the Core i9-10900X – Intel’s other 10-core CPU for its X299 platform.

There’s also the issue of power consumption. Rumours before the launch painted concerning pictures, but while we saw our test system hit 300W under load with the Core i9-10900K installed, that’s only 67W more than with the Core i9-9900K, and 60W more than the Ryzen 9 3900X, although the latter admittedly has two more cores and costs around £90 less than the Core i9-10900K.

Intel's Comet Lake CPUs require a new motherboard with the company's LGA1200 socket

Intel has at least attempted to solve the issue of heat, which could be a real issue with the Core i9-9900K, especially when overclocking. The Core i9-10900K sports some tweaks here compared with its forebear, with a die that’s 0.3mm thinner than its predecessor, but a heatspreader that’s thicker, resulting in a CPU that maintains compatibility with older LGA115x-compatible CPU coolers.

The die is less thermally conductive than the heatspreader, so it makes sense to keep it as thin as possible, while the heatspreader is made from nickel-plated copper, making for an excellent heat conductor. This arrangement, Intel hopes, will allow the CPU to scale further with more cooling power, so better cooling may well yield more overclocking headroom. We’ll be investigating this in a future issue.

Intel Core i9-10900K

Performance

When overclocking the Core i9-10900K, we managed to get our system to boot at 5.2GHz with a 1.35V vcore, but this failed our stress test. In the end, we reined in the clock speed to 5.1GHz using a vcore of 1.3V, where temperatures sat in the low 80s (°C) with our liquid-cooling system, compared to 10-15°C lower at stock speed.

This highlights just how much Intel is pushing the limits, as usually we can match Intel’s stock speed peak boost frequency with an all-core overclock quite easily, but there’s very little overclocking headroom here.

In our RealBench tests, the Ryzen 9 3900X was faster than the Core i9-10900K, beating the Intel CPU everywhere except our heavy multi-tasking test. However, despite a 2-core deficit, the Intel CPU held its own and was never far behind, with its system score sitting just 12,000 points adrift.

It was significantly faster than the Ryzen 7 3800X, Core i9-9900K and Core i5-10600K overall too. Overclocking the Core i9-10900K helped to boost its image editing score hugely too, where it closed the gap on the Ryzen 9 3900X.

The extra clock speed also saw the Intel chip top the single-threaded Cinebench R20 graph with a score of 532. Once overclocked, that score fell by 11 points thanks to our overclocking dipping below the stock speed boost frequency.

AMD still has an advantage in the multi-threaded Cinebench test with the Ryzen 9 3900X, but the Ryzen 7 3800X came a very distant third place here, with overclocking doing little to change the situation.

Games are clearly still Intel’s domain, although a lot of the benefits depend on your settings and setup. Even without a monstrous RTX 2080 Ti at the helm, we still saw much better performance in Far Cry New Dawn from the Core i9-10900K than with any AMD CPU at 1080p at ultra settings, and the game still prefers CPUs without Hyper-Threading, giving the Core i7-9700K the lead.

Interestingly, the cheaper Core i5-10600K was never far behind here either. Overclocking helped the AMD CPUs in this test, but ultimately, you’ll need a far more GPU-limited situation than our RTX 2070 Super to see a closer gap between these CPUs in this game at these settings.

In our more GPU-limited Metro Exodus test, the differences in percentage terms persisted, with the Core i9-10900K’s 43fps 99th percentile minimum frame rate being 5 per cent higher than the Ryzen 9 3900X’s result, and 15 per cent higher once overclocked.

Meanwhile, power consumption was high, but not enough to warrant buying a new power supply, peaking at 300W at stock speed for our Core i9-10900K test system, and 349W overclocked.

Intel Core i9-10900K

Conclusion

The Core i9-10900K is a beast of a gaming CPU; it’s also rapid in content creation, closely following the Ryzen 9 3900X in many tests, despite having fewer cores. AMD’s 3rd-gen Ryzen CPUs offer better value when it comes to content creation, but they lack the all-round chart-topping gaming performance of the Core i9-10900K.

However, if gaming is your top priority, you can get very similar performance from the new Core i5-10600K, which also offers AMD-beating gaming performance and was a match for AMD’s 6-core and 8-core CPUs in many multi-threaded tests.

If you want the absolute fastest gaming CPU, along with decent multi-threading performance, the Core i9-10900K is at the top of its league, but if funds are limited and games are your top priority, you’d be much better off buying a cheaper CPU and a faster graphics card instead.

Extreme Ultra Award

VERDICT
Ridiculously fast in games, but AMD’s 3rd-gen Ryzen CPUs offer much better value, especially for multi-threading.

PRICE
£540 inc VAT

SCORES
PERFORMANCE 47/50 / FEATURES 13/15 / VALUE 26/35 / OVERALL 86%

TENNER
+Massive gaming performance
+Same launch price as Core i9-9900K
+Decent multi-threaded performance

10p COIN
-Needs new motherboard
-AMD better value for multi-threading
-Core i5-10600K is nearly as fast

SPEC
Base frequency 3.3GHz
Max boost frequency 5.3GHz
Core Comet Lake
Manufacturing process 14nm
Number of cores 10 x physical (20 threads)
Hyper-Threading Yes
Cache 19MB L3, 10 x 1MB L2
Memory controller Dual-channel DDR4, up to 2933MHz

Packaging LGA1200
Thermal design power (TDP) 125W
Features Thermal Velocity Boost, Turbo Boost Max Technology 3, Turbo Boost 2, FMA3, F16C, SHA, BMI / BMI1 + BMI2, AVX-512, AVX2, AVX, AES, SSE4a, SSE4, SSSE3, SSE3, SSE2, SSE, MMX

Intel Comet Lake Benchmarks

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