Intel Core i9-9820X vs Intel Core i9-9900X Comparison

Head-to-Head Benchmarks

The benchmark data shows a clear, consistent pattern: the Intel Core i9-9900X wins every single head-to-head test against the Intel Core i9-9820X. Across six recorded benchmarks, the 9900X takes all six victories, with the 9820X failing to claim a single win. The margin is remarkably uniform, which points to a structural advantage rather than workload-specific behavior.

In Cinebench R15 multicore, the 9900X scores 1851 against 1759 for the 9820X, a 5.2% advantage. The single-core R15 result follows the same trajectory: 261 versus 248, again a 5.2% delta. This consistency carries into Cinebench R20, where the 9900X posts 7713 multicore and 1088 single-core, while the 9820X manages 7332 and 1034 respectively. Both represent the same 5.2% gap.

The newest rendering test in the database, Cinebench R23, reinforces the pattern. The 9900X delivers 18365 multicore and 2592 single-core, compared to 17459 and 2464 for the 9820X. Every delta across all six benchmarks sits at exactly 5.2%, indicating that the performance difference scales uniformly across both lightly threaded and heavily threaded workloads.

The Geekbench results, though not part of the head-to-head table, corroborate the story from the average benchmark scores. The 9900X records an average benchmark score of 5301 across all its tests, while the 9820X averages 5049. That gap of roughly 5% aligns closely with the 5.2% deltas seen in the Cinebench suite. The 9900X also holds a Geekbench multicore score of 9109 and a single-core score of 1429, figures that are not directly mirrored for the 9820X in the database, but the average scores already place the 9900X ahead.

Looking at the broader competitive landscape, the 9900X sits at the 60th percentile among all CPUs, and the 9820X also sits at the 60th percentile. Their nearest rivals in the database explain where each lands. The 9900X is essentially tied with the AMD Ryzen Threadripper 1920X, which averages 5306, a delta of just -0.1%. It also sits within 0.3% of the AMD EPYC 7281 and Intel Core i9-10900KF, and within 0.8% of the Intel Core i9-13900TE. The 9820X, by contrast, matches the Intel Core i9-12900TE exactly at 5050, a 0% delta, and sits within 0.5% of the Intel Xeon W-2155.

The implication is that the 9900X is not just faster than the 9820X, it is positioned in a higher performance tier altogether. The 9820X competes with lower-end workstation and embedded parts, while the 9900X trades blows with high-end desktop and server processors from the same era.

The Verdict

The data is unambiguous. The Intel Core i9-9900X outperforms the Intel Core i9-9820X in every recorded benchmark, and the margin is identical across all six head-to-head tests. Anyone choosing between these two strictly on measured performance should pick the 9900X. It delivers 5.2% more multicore throughput and 5.2% more single-core throughput in Cinebench R15, R20, and R23. That uniformity means the advantage holds regardless of whether the workload is a short single-threaded task or a long multi-threaded render.

The 9820X is not a bad processor in absolute terms. Its average benchmark score of 5049 puts it at the 60th percentile, and it matches the Intel Core i9-12900TE exactly in average score. But relative to the 9900X, it is consistently behind. The 9900X averages 5301, which is 5% higher, and its nearest rivals include the AMD Ryzen Threadripper 1920X and Intel Core i9-10900KF, both of which are more potent competitors than anything in the 9820X's immediate vicinity.

The 9820X does have one advantage in the database: its launch MSRP of $889. The 9900X carries a launch MSRP of $989. But the benchmark results indicate that the 9900X justifies that positioning with a uniform performance lead. For workloads that rely on Cinebench-style rendering, the 9900X is the clear choice. The 9820X only makes sense if the lower launch MSRP is the deciding factor, and even then, the performance gap is consistent across every test.

Both processors share the same socket, architecture, and core count, so platform costs would be identical. The 9900X simply extracts more performance from the same underlying design. The verdict from the recorded data: the 9900X is the faster part, and the 9820X is the more modestly priced entry point into the same platform.

Architecture Differences

Both processors are built on the Skylake architecture, specifically the Skylake-X codename, and both belong to the Core i9 X-Series 9th Generation. They use the same 14 nm process node from Intel, and both are manufactured by Intel. The core configuration is identical: 10 cores and 20 threads on each chip.

The L1 and L2 caches match exactly. Each core gets 64 KB of L1 cache and 1 MB of L2 cache. The difference appears in the L3 cache. The 9900X has 19.25 MB of shared L3 cache, while the 9820X has 16.5 MB. That is a 2.75 MB advantage for the 9900X, which helps explain its consistent performance lead. Larger shared cache can reduce memory latency and improve hit rates in multi-threaded workloads, and the benchmark data supports that interpretation.

Memory support is identical on both. Each supports DDR4 memory through a quad-channel bus with a memory bandwidth of 85.3 GB/s. Neither supports ECC memory. PCIe connectivity is also the same: Gen 3 with 44 lanes available from the CPU.

Both processors have an unlocked multiplier, meaning overclocking is possible on either chip. Neither has integrated graphics, so a discrete GPU is required. Both are marked as end-of-life in production status, and both were released on the same date: October 18, 2018.

The architecture differences boil down to one meaningful spec: L3 cache capacity. Everything else, from the core count to the memory controller to the PCIe configuration, is shared between the two parts.

Specification Differences

The specification sheets for the two processors show only a few divergences, but each one matters.

Clock speeds are the most obvious difference. The 9900X has a base clock of 3.50 GHz and a boost clock of 4.50 GHz. The 9820X runs at 3.30 GHz base and 4.20 GHz boost. That is a 0.20 GHz advantage for the 9900X at both base and boost, which directly contributes to its higher single-core and multicore scores.

L3 cache differs as noted: 19.25 MB on the 9900X versus 16.5 MB on the 9820X. The L1 and L2 caches are identical at 64 KB per core and 1 MB per core respectively.

The launch MSRP differs by $100. The 9900X launched at $989, while the 9820X launched at $889. Both are end-of-life parts, and both have unlocked multipliers.

The part numbers also differ: SREZ7 for the 9900X and SREZ8 for the 9820X. This is simply a manufacturing identifier, but it is the only other field that separates the two in the database.

The remaining specs are shared: 10 cores, 20 threads, 165 W TDP, Intel Socket 2066, Skylake-X architecture, 14 nm process, quad-channel DDR4 memory, 85.3 GB/s memory bandwidth, no ECC support, no integrated graphics, Gen 3 PCIe with 44 lanes, and an October 18, 2018 release date.

FAQ

Q: Which processor is faster in multi-threaded workloads?

A: The Intel Core i9-9900X is faster. In Cinebench R23 multicore, it scores 18365 versus 17459 for the 9820X, a 5.2% advantage. The same 5.2% delta appears in Cinebench R15 multicore (1851 versus 1759) and Cinebench R20 multicore (7713 versus 7332).

Q: How do the two chips compare in single-threaded performance?

A: The 9900X leads by 5.2% in every single-core test. Cinebench R15 shows 261 versus 248, R20 shows 1088 versus 1034, and R23 shows 2592 versus 2464.

Q: Do both processors have the same number of cores and threads?

A: Yes. Both have 10 cores and 20 threads, with the same 64 KB L1 and 1 MB L2 cache per core. The 9900X has more L3 cache: 19.25 MB shared versus 16.5 MB shared on the 9820X.

Q: What is the average benchmark score for each processor?

A: The 9900X averages 5301 across its recorded benchmarks, placing it at the 60th percentile. The 9820X averages 5049, also at the 60th percentile.

Q: Are there any benchmarks where the 9820X wins?

A: No. Out of six head-to-head benchmark comparisons, the 9900X wins all six. The 9820X does not record a single victory.

Q: What are the closest rivals for each processor?

A: The 9900X is closest to the AMD Ryzen Threadripper 1920X, which averages 5306, a delta of -0.1%. The 9820X is exactly tied with the Intel Core i9-12900TE at 5050, a 0% delta.