Intel Core i9-7900X vs Intel Core i9-9900X Comparison

Where Each One Wins

The Intel Core i9-9900X and Intel Core i9-7900X are both 10-core, 20-thread desktop processors built on the Skylake-X architecture and sharing the Intel Socket 2066 platform. The recorded data shows a clear overall advantage for the i9-9900X, which wins 7 of the 8 head-to-head benchmark comparisons. The i9-7900X claims only a single victory, and by a very narrow margin, in Geekbench single-core testing.

The i9-9900X establishes its dominance across every multi-threaded workload in the database. In Cinebench R15 multi-core, it scores 1851 against 1782 for the i9-7900X, a 3.9% advantage. That pattern repeats in Cinebench R20 multi-core (7713 versus 7425, also 3.9%) and Cinebench R23 multi-core (18365 versus 17680, again 3.9%). The consistency of the multi-core margin across three generations of the Cinebench suite suggests a structural advantage rather than workload-specific luck. Geekbench multi-core follows the same trend, with the i9-9900X scoring 9109 versus 8841, a 3% lead.

Single-threaded performance is also largely in favor of the i9-9900X, but the margin is slightly smaller. In Cinebench R15 single-core, it scores 261 versus 251, a 4% gain. Cinebench R20 single-core shows 1088 versus 1048, a 3.8% advantage, and Cinebench R23 single-core shows 2592 versus 2496, also 3.8%. The one exception is Geekbench single-core, where the i9-7900X scores 1437 against 1429, a 0.6% edge. This is the only benchmark in the entire comparison where the older processor wins, and the margin is small enough to be considered effectively a tie within normal run-to-run variation.

Looking at the broader database context, both processors sit at the 60th percentile among all CPUs. The i9-9900X has an average benchmark score of 5301, which places it within 0.1% of the AMD Ryzen Threadripper 1920X (5306) and within 0.3% of both the AMD EPYC 7281 (5315) and the Intel Core i9-10900KF (5316). The i9-7900X averages 5120, sitting 0.2% above the AMD EPYC 7262 (5109), 0.5% above the Intel Core i7-11850HE (5095), 0.9% above the Intel Xeon W-2155 (5072), and 1% above the AMD Ryzen 7 PRO 5750GE (5070). In short, the i9-9900X competes with slightly faster company in the database rankings, while the i9-7900X sits alongside somewhat slower parts.

FAQ

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

A: The Intel Core i9-9900X wins every multi-core benchmark in the database. It leads by 3.9% in Cinebench R15, R20, and R23 multi-core, and by 3% in Geekbench multi-core.

Q: Does the i9-7900X win any benchmark at all?

A: Yes. It wins Geekbench single-core with a score of 1437 versus 1429 for the i9-9900X, a 0.6% margin. This is the only one of the 8 recorded head-to-head benchmarks that the i9-7900X wins.

Q: What is the average benchmark score difference between the two?

A: The i9-9900X has an average benchmark score of 5301, while the i9-7900X averages 5120. The difference is 181 points, or roughly 3.5% in favor of the i9-9900X.

Q: Do both processors support the same memory configuration?

A: Yes. Both support DDR4 memory over a quad-channel bus with an identical memory bandwidth of 85.3 GB/s, and neither supports ECC memory.

Q: Are both processors unlocked for overclocking?

A: Yes. Both have an unlocked multiplier, and both are end-of-life production parts.

Q: How do these processors compare to their nearest rivals in the database?

A: The i9-9900X is within 0.1% of the AMD Ryzen Threadripper 1920X and within 0.3% of the AMD EPYC 7281 and Intel Core i9-10900KF. The i9-7900X is 0.2% above the AMD EPYC 7262, 0.5% above the Intel Core i7-11850HE, 0.9% above the Intel Xeon W-2155, and 1% above the AMD Ryzen 7 PRO 5750GE.

Head-to-Head Benchmarks

The largest single benchmark victory for the i9-9900X comes in Cinebench R15 single-core, where it scores 261 against 251 for the i9-7900X, a 4% delta. That is the only test with a margin above 3.9%. The multi-core Cinebench results are remarkably consistent: R15 shows 1851 versus 1782, R20 shows 7713 versus 7425, and R23 shows 18365 versus 17680, each at 3.9%. This uniform margin across workloads that scale differently with core count, memory bandwidth, and cache suggests the i9-9900X's advantage is tied to a fundamental clock or efficiency improvement rather than to any single workload characteristic.

The single-core Cinebench results show slightly smaller margins. Cinebench R20 single-core gives the i9-9900X a 3.8% lead (1088 versus 1048), and Cinebench R23 single-core also shows 3.8% (2592 versus 2496). The Geekbench multi-core test is the smallest multi-threaded win for the i9-9900X at 3% (9109 versus 8841). Interestingly, the Geekbench single-core test is the only benchmark where the i9-7900X comes out ahead, scoring 1437 versus 1429, a 0.6% margin.

The base clock difference between the two processors is 3.50 GHz for the i9-9900X versus 3.30 GHz for the i9-7900X, a 200 MHz gap that likely explains much of the consistent performance edge. Both processors boost to 4.50 GHz, so the advantage manifests most clearly in sustained workloads where the higher base clock allows the i9-9900X to maintain higher frequencies under load. The i9-9900X also carries a higher TDP of 165 watts versus 140 watts for the i9-7900X, which gives it additional thermal headroom to sustain that higher base clock.

In the context of the database's nearest rivals, the i9-9900X's average score of 5301 puts it essentially at parity with the AMD Ryzen Threadripper 1920X (5306, a 0.1% deficit) and just below the AMD EPYC 7281 and Intel Core i9-10900KF (both 5315 and 5316, a 0.3% deficit). The i9-7900X, with an average of 5120, sits slightly above its nearest rivals: 0.2% above the AMD EPYC 7262, 0.5% above the Intel Core i7-11850HE, 0.9% above the Intel Xeon W-2155, and 1% above the AMD Ryzen 7 PRO 5750GE.

Specification Differences

The two processors share a substantial number of specifications. Both have 10 cores, 20 threads, a 4.50 GHz boost clock, a 14 nm process node, Intel Socket 2066, DDR4 memory support, quad-channel memory bus, 85.3 GB/s memory bandwidth, no ECC support, PCIe Gen 3 with 44 CPU lanes, no integrated graphics, an unlocked multiplier, and desktop market segment status. Both are also end-of-life.

The differences are concentrated in a few areas. The base clock differs: 3.50 GHz for the i9-9900X versus 3.30 GHz for the i9-7900X. The TDP differs as well, with the i9-9900X rated at 165 watts and the i9-7900X at 140 watts. The L3 cache is larger on the i9-9900X at 19.25 MB shared, versus 14 MB shared on the i9-7900X. The generation label differs: the i9-9900X is listed as Core i9 X-Series 9th Gen, while the i9-7900X is Core i9 X-Series 7th Gen. Their release dates are also different, with the i9-9900X released on 2018-10-18 and the i9-7900X on 2017-06-25. The part numbers differ as well: SREZ7 for the i9-9900X and SR3L2 for the i9-7900X. The launch MSRP for the i9-9900X was $989, and the launch MSRP for the i9-7900X was $999.

The L1 and L2 cache configurations are identical: 64 KB per core for L1 and 1 MB per core for L2. Memory bandwidth is also identical at 85.3 GB/s, as is the PCIe configuration. Neither processor has a listed integrated GPU, and neither supports ECC memory.

Architecture Differences

Both processors are built on the Skylake architecture, specifically the Skylake-X codename, and both are fabricated on Intel's 14 nm process at Intel's own foundry. The core and thread counts are identical at 10 cores and 20 threads. The L1 and L2 cache structures are the same, with 64 KB of L1 per core and 1 MB of L2 per core.

The architecture differences that matter for performance are the L3 cache size and the clock strategy. The i9-9900X has 19.25 MB of shared L3 cache, which is 5.25 MB more than the 14 MB on the i9-7900X. This larger cache can improve performance in workloads with larger working sets that benefit from more on-die data. The i9-9900X also runs a higher base clock of 3.50 GHz versus 3.30 GHz, with the same 4.50 GHz boost clock. The higher TDP of 165 watts for the i9-9900X, compared to 140 watts for the i9-7900X, reflects the additional power budget required to sustain that higher base frequency.

The generation placement in the product stack differs, with the i9-9900X belonging to the X-Series 9th Gen and the i9-7900X to the X-Series 7th Gen. This is essentially a refresh of the same underlying Skylake-X design, with the newer part receiving a higher base clock and more L3 cache. The platform features are otherwise identical: both use Intel Socket 2066, both support quad-channel DDR4 with 85.3 GB/s of bandwidth, and both provide PCIe Gen 3 with 44 CPU lanes. Neither processor includes ECC memory support or integrated graphics.

The practical effect of these architectural differences is visible in the benchmark results. The i9-9900X's larger L3 cache and higher base clock translate into a consistent 3.8% to 4% advantage across most tests, with the only exception being the Geekbench single-core test where the older i9-7900X edges ahead by 0.6%. The 200 MHz base clock gap is the most probable driver of the multi-core differences, since both parts share the same boost clock and core topology. The additional L3 cache likely contributes in memory-sensitive workloads, though the benchmark data does not isolate its effect independently of the clock difference.