Intel Core i9-10850K vs Intel Core i9-9820X Comparison

Head-to-Head Benchmarks

The recorded data shows a clean sweep for the Intel Core i9-10850K across every shared benchmark. In Cinebench R15 multicore, the 10850K scores 1873 against the 9820X's 1759, a 6.5% advantage. Single-core R15 shows the same gap: 264 versus 248, again 6.5%. The pattern continues in Cinebench R20, where the 10850K reaches 7808 in multicore and 1102 in single-core, while the 9820X manages 7332 and 1034 respectively. Those deltas sit at 6.5% and 6.6%. The most demanding test, Cinebench R23, reinforces the trend: the 10850K posts 18592 multicore and 2624 single-core, compared to 17459 and 2464 for the 9820X, both exactly 6.5% apart.

What stands out is the consistency. Every single workload, whether it stresses one core or all twenty threads, yields nearly the same percentage gap. This suggests the difference is not workload-dependent but rather a fundamental clock speed and architectural efficiency advantage. The 10850K's boost clock reaches 5.20 GHz while the 9820X tops out at 4.20 GHz, a full 1.00 GHz difference. That explains why the single-core tests show identical margins to the multicore tests: the per-thread speed advantage carries through regardless of how many cores are engaged.

Neither processor has any additional benchmark data beyond these six Cinebench tests in the head-to-head comparison. The 10850K does have a richer individual benchmark profile, including 3DMark and Geekbench results, but those have no direct counterpart for the 9820X in the database. The average benchmark score for the 10850K is 5240, while the 9820X sits at 5049. The 10850K's nearest rival is the Intel Core i7-11700B at 5241, a negligible 0% difference, followed by the Core i5-14401E at 5253 (0.2% behind) and the Xeon E5-2699A v4 at 5259 (0.4% behind). The 9820X's closest competitor is the Core i9-12900TE at 5050, with the Xeon Gold 6334 at 5043 (0.1% ahead) and the Ryzen 7 PRO 5750GE at 5070 (0.4% behind). Both CPUs sit at the 60th percentile among all processors in the database.

The Verdict

The data points to one unambiguous conclusion: the Core i9-10850K outperforms the Core i9-9820X in every measured category. Across six direct comparisons, the 10850K wins all six, with margins ranging from 6.5% to 6.6%. The average benchmark score difference is 5240 versus 5049, about 3.8% in favor of the newer chip. Both are 10-core, 20-thread desktop processors, so the comparison is apples to apples on core count. The deciding factor is the massive clock speed advantage: 5.20 GHz boost versus 4.20 GHz boost. The 10850K also carries a lower thermal design power at 125 watts versus 165 watts, meaning it delivers more performance while drawing less power.

Who should choose the 10850K? Anyone whose workload is dominated by the Cinebench family of tests, which typically reflects rendering, video encoding, and general multi-threaded productivity. The 10850K is also the better pick for single-thread-sensitive applications, given its 6.5% lead in every single-core test. Who should choose the 9820X? The data does not support that choice on pure performance grounds. The 9820X wins zero benchmarks in the head-to-head set. Its only advantages lie outside raw compute: it supports quad-channel memory with 85.3 GB/s bandwidth versus dual-channel 46.9 GB/s for the 10850K, and it offers 44 PCIe Gen 3 lanes versus 16. Those are real differences that matter for memory-hungry or expansion-heavy systems, but they do not translate into a performance win in any benchmark recorded here. The 9820X also carries a launch MSRP of $889, which the database records as a specification, not a recommendation.

Architecture Differences

The two processors come from different architectural lineages. The 10850K uses Comet Lake, Intel's 14 nm process node, with a die size of 206 mm². The 9820X uses Skylake, also on the 14 nm node, but built on the Skylake-X variant for the HEDT platform. Both are manufactured by Intel and both are end-of-life products, but they target different sockets and platforms. The 10850K fits Intel Socket 1200, the mainstream desktop socket for 10th Gen Core. The 9820X uses Intel Socket 2066, the enthusiast platform socket.

Cache layouts differ substantially. Both have 64 KB of L1 cache per core. The L2 cache, however, is 256 KB per core on the 10850K but 1 MB per core on the 9820X. That is a fourfold difference in L2 capacity per core, which could help the 9820X in workloads with high per-thread working sets. The L3 cache tells the opposite story: the 10850K has 20 MB shared, while the 9820X has 16.5 MB shared. The 10850K's larger L3 is likely a factor in its benchmark wins, as shared cache is critical for multi-threaded communication and data reuse.

The 9820X has no integrated graphics, while the 10850K includes UHD Graphics 630. This matters for systems without a discrete GPU, but it is not directly reflected in the CPU benchmarks. The 9820X's HEDT heritage shows in its memory controller and PCIe configuration: quad-channel DDR4 with 85.3 GB/s bandwidth and 44 PCIe Gen 3 lanes, versus dual-channel with 46.9 GB/s and 16 lanes on the 10850K. Neither supports ECC memory. Both have unlocked multipliers, so overclocking is possible on either platform, though the 10850K's already higher boost clock gives it a head start.

Specification Differences

The core counts are identical: 10 cores and 20 threads each. The base clocks differ: 3.60 GHz for the 10850K versus 3.30 GHz for the 9820X. Boost clocks differ even more: 5.20 GHz versus 4.20 GHz. Thermal design power is 125 watts for the 10850K and 165 watts for the 9820X. The 10850K uses Socket 1200, the 9820X uses Socket 2066. The 10850K has a die size of 206 mm², while the 9820X has no recorded die size.

Cache configuration differs at L2 and L3. The 10850K has 256 KB L2 per core, the 9820X has 1 MB L2 per core. L3 is 20 MB shared on the 10850K versus 16.5 MB shared on the 9820X. Memory bus width is dual-channel on the 10850K and quad-channel on the 9820X, with corresponding bandwidth figures of 46.9 GB/s and 85.3 GB/s. PCIe lane counts are 16 for the 10850K and 44 for the 9820X, both Gen 3. The 10850K includes UHD Graphics 630, the 9820X has none. The 9820X has a launch MSRP of $889; the 10850K has no recorded launch MSRP. Release dates differ: July 2020 for the 10850K, October 2018 for the 9820X. The part numbers are SRK51 for the 10850K and SREZ8 for the 9820X.

FAQ

Q: Which CPU has the higher boost clock?

A: The Intel Core i9-10850K boosts to 5.20 GHz, while the Intel Core i9-9820X boosts to 4.20 GHz, a difference of 1.00 GHz in favor of the 10850K.

Q: Do both CPUs have the same core and thread counts?

A: Yes, both have 10 cores and 20 threads.

Q: Which processor has more PCIe lanes?

A: The Intel Core i9-9820X has 44 PCIe Gen 3 lanes, while the Intel Core i9-10850K has 16 PCIe Gen 3 lanes.

Q: How much faster is the 10850K in Cinebench R23 multicore?

A: The 10850K scores 18592 versus 17459 for the 9820X, which is a 6.5% difference.

Q: Does the 9820X support ECC memory?

A: No, ECC memory is not supported on either processor.

Q: Which CPU has integrated graphics?

A: Only the Intel Core i9-10850K includes integrated graphics (UHD Graphics 630). The Intel Core i9-9820X has no integrated graphics.

Where Each One Wins

The Intel Core i9-10850K wins in every benchmark category that the database records for both chips. That includes all six Cinebench tests: R15 multicore and single-core, R20 multicore and single-core, and R23 multicore and single-core. The margins are consistent at 6.5% to 6.6%, which makes the 10850K the clear choice for rendering, video editing, 3D modeling, and any workload that scales with clock speed. Its lower TDP of 125 watts versus 165 watts also means less heat generation and potentially simpler cooling requirements, though the database does not record cooler specifications.

The Intel Core i9-9820X does not win any CPU benchmark, but it holds advantages in platform features that are not captured by the Cinebench scores. Its quad-channel memory controller delivers 85.3 GB/s of bandwidth, nearly double the 46.9 GB/s of the 10850K. That could benefit workloads that are heavily memory-bandwidth-bound, such as large-scale data processing, scientific computing, or virtual machine hosting, where memory throughput matters more than raw core speed. The 9820X also offers 44 PCIe lanes, allowing more expansion cards, NVMe drives, or GPUs to be connected directly to the CPU. For a system built around many peripherals or high-bandwidth storage arrays, the 9820X's platform connectivity is a genuine advantage, even if its compute performance trails.

The 9820X's larger L2 cache (1 MB per core versus 256 KB per core) is another differentiator that could matter in specific workloads with high per-thread cache reuse. However, the benchmark data shows that this L2 advantage does not translate into wins in the Cinebench suite. The 10850K counters with a larger L3 cache (20 MB versus 16.5 MB), which appears to be more impactful for the tested workloads.

In summary, the 10850K is the superior processor for compute-heavy tasks as measured by the database. The 9820X is the better platform choice for users who need maximum memory bandwidth and PCIe expansion, accepting a measurable performance penalty in CPU-bound benchmarks. The data does not show a scenario where the 9820X wins a CPU benchmark, so its appeal rests entirely on platform features rather than raw compute.