AMD Ryzen 9 3950X vs Intel Core i9-9900KS Comparison

The AMD Ryzen 9 3950X and Intel Core i9-9900KS are two desktop processors from 2019 that took opposite approaches to high-end performance. The Ryzen 9 3950X is a 16-core, 32-thread processor built on AMD's 7 nm Zen 2 architecture, while the Core i9-9900KS is an 8-core, 16-thread part based on Intel's 14 nm Coffee Lake Refresh design, with both chips holding a 59th percentile ranking among all CPUs. The benchmark data reveals a clear split: the Ryzen 9 dominates multi-threaded workloads, while the Core i9-9900KS holds a consistent edge in lightly-threaded and single-core tests. This head-to-head analysis breaks down those differences using the exact scores from the Fact Pack.

Head-to-Head Benchmarks

The Ryzen 9 3950X delivers its most emphatic victory in Cinebench R15 multi-core, where it scores 4002 against the Core i9-9900KS's 1657. That is a 141.5% advantage, the largest delta in the entire comparison. The 16-core part also wins 3DMark Max Threads by a wide margin, scoring 10719 versus 7360, a 45.6% lead. In Geekbench multi-core, the Ryzen 9 posts 12088, which is 23.7% higher than the Intel's 9771. The 3DMark 16-thread test also goes to AMD, with 9338 versus 7376, a 26.6% win. These four victories for the Ryzen 9 all come in tests that scale with core count, reflecting its 16 cores and 32 threads.

The Core i9-9900KS, despite having half the cores, wins six of the ten head-to-head benchmarks. Its largest single win is in 3DMark 2 Threads, where it scores 1670 against 1436, a 14% advantage. The Intel chip also takes 3DMark 4 Threads with 3276 versus 2795, a 14.7% lead, and 3DMark 8 Threads with 5787 versus 5299, an 8.4% margin. In single-threaded tests, the Core i9-9900KS is consistently ahead: 3DMark Single Thread shows 841 versus 726 (13.7% higher), Cinebench R15 Single Core shows 233 versus 209 (10.3% higher), and Geekbench Single Core shows 1715 versus 1454 (15.2% higher). These wins indicate that the Intel part has a stronger per-core performance, which is also visible in its higher boost clock of 5.00 GHz compared to the Ryzen 9's 4.70 GHz.

The average benchmark scores tell a similar story. The Ryzen 9 3950X has an average score of 4807, while the Core i9-9900KS averages 4738, a difference of less than 1.5%. The nearest rivals for the Ryzen 9 include the Intel Xeon E-2386G (0.2% ahead) and the AMD Ryzen 7 5800HS (0.4% behind), showing it sits in a tight cluster. For the Core i9-9900KS, the nearest rivals are the Intel Core i7-6950X (0.1% ahead) and the Intel Core i9-10900E (0.6% ahead), indicating a similar level of competition. These margins suggest that neither chip is overwhelmingly faster overall, but their strengths are sharply divided by thread count.

Architecture Differences

The most significant architectural difference is the core count: the Ryzen 9 3950X has 16 cores and 32 threads, while the Core i9-9900KS has 8 cores and 16 threads. This doubling of resources is the primary reason for the Ryzen 9's multi-threaded dominance. The process node also differs substantially, with AMD using TSMC's 7 nm process for the Matisse chip, while Intel uses its own 14 nm process for Coffee Lake-R. This node advantage helps explain the Ryzen 9's lower TDP of 105 watts despite having twice the cores, compared to the Core i9-9900KS's 127-watt TDP.

Cache configurations also diverge. The Ryzen 9 3950X has 64 KB of L1 cache per core, 512 KB of L2 cache per core, and a large 64 MB L3 cache. The Core i9-9900KS has the same 64 KB L1 per core, but only 256 KB of L2 per core and 16 MB of shared L3 cache. The Ryzen 9's larger L3 cache is likely a factor in its ability to feed 16 cores effectively. The Intel part also has a smaller die size of 180 mm², while the Ryzen 9 uses a chiplet design with two 74 mm² dies, totaling 148 mm², and contains 7,600 million transistors.

Memory bandwidth differs as well, with the Ryzen 9 offering 51.2 GB/s versus the Core i9-9900KS's 42.7 GB/s, both over dual-channel DDR4. PCIe support is another differentiator: the Ryzen 9 supports PCIe Gen 4 with 24 lanes, while the Core i9-9900KS is limited to PCIe Gen 3 with 16 lanes. The Intel chip includes integrated UHD 630 graphics, whereas the Ryzen 9 has no integrated graphics and requires a discrete GPU. Both processors have unlocked multipliers, but the Core i9-9900KS uses the Intel Socket 1151, while the Ryzen 9 uses AMD Socket AM4. The Ryzen 9 is still in active production, while the Core i9-9900KS is marked as end-of-life, and neither supports ECC memory.

The launch MSRP for the Ryzen 9 3950X was $749, while the Core i9-9900KS launched at $513. The Ryzen 9 also has a more recent release date of November 24, 2019, compared to the Intel part's October 27, 2019 launch.

The Verdict

The data shows a clear choice based on workload. For any heavily multi-threaded task, the Ryzen 9 3950X is the superior processor. Its 141.5% lead in Cinebench R15 Multi Core and 45.6% lead in 3DMark Max Threads are decisive, and the 23.7% advantage in Geekbench Multi Core confirms the trend. Users running video rendering, 3D modeling, or other parallel workloads should choose the Ryzen 9, as it scores 12088 in Geekbench Multi Core versus 9771 for the Intel part. The Ryzen 9 also has the advantage of being a 7 nm part with a lower 105-watt TDP, making it more power-efficient per core.

For users prioritizing single-threaded performance or gaming with lower thread counts, the Core i9-9900KS wins every single-core test. It leads by 13.7% in 3DMark Single Thread (841 versus 726), 10.3% in Cinebench R15 Single Core (233 versus 209), and 15.2% in Geekbench Single Core (1715 versus 1454). The Intel chip also wins 3DMark 2, 4, and 8 Thread tests, suggesting it is better for applications that use up to eight threads, which covers many gaming scenarios. The Core i9-9900KS's boost clock of 5.00 GHz is a key factor in these wins, while the Ryzen 9's boost clock tops out at 4.70 GHz.

The overall average scores are nearly identical, with the Ryzen 9 at 4807 and the Core i9-9900KS at 4738, a difference of roughly 1.4%. This means the decision should not be about which is generally faster, but which fits the user's specific workload. The Ryzen 9 also offers more future-proofing with PCIe Gen 4 support and a larger 64 MB L3 cache, while the Core i9-9900KS is end-of-life. Strictly from the benchmark data, the Ryzen 9 3950X is the pick for productivity, and the Core i9-9900KS is the pick for low-thread-count performance.

FAQ

Q: Which processor wins in multi-core benchmarks?

A: The AMD Ryzen 9 3950X wins all multi-core tests, including a 141.5% lead in Cinebench R15 Multi Core (4002 versus 1657), a 45.6% lead in 3DMark Max Threads (10719 versus 7360), and a 23.7% lead in Geekbench Multi Core (12088 versus 9771).

Q: Which processor has the higher single-thread score?

A: The Intel Core i9-9900KS wins every single-thread test, with a 13.7% lead in 3DMark Single Thread (841 versus 726), a 10.3% lead in Cinebench R15 Single Core (233 versus 209), and a 15.2% lead in Geekbench Single Core (1715 versus 1454).

Q: How many cores and threads does each processor have?

A: The AMD Ryzen 9 3950X has 16 cores and 32 threads, while the Intel Core i9-9900KS has 8 cores and 16 threads.

Q: What is the process node for each chip?

A: The AMD Ryzen 9 3950X is built on TSMC's 7 nm process, while the Intel Core i9-9900KS uses Intel's 14 nm process.

Q: Which chip has integrated graphics?

A: The Intel Core i9-9900KS includes Intel UHD 630 integrated graphics, while the AMD Ryzen 9 3950X does not have integrated graphics.

Q: What is the TDP of each processor?

A: The AMD Ryzen 9 3950X has a TDP of 105 watts, while the Intel Core i9-9900KS has a TDP of 127 watts.

Where Each One Wins

The AMD Ryzen 9 3950X is the clear winner in all multi-threaded scenarios. The data shows it is 141.5% faster in Cinebench R15 Multi Core, 45.6% faster in 3DMark Max Threads, and 23.7% faster in Geekbench Multi Core. These results make it the better choice for professional workloads like video encoding, 3D rendering, and software compilation, where all 16 cores and 32 threads can be utilized. Its 64 MB L3 cache and 51.2 GB/s memory bandwidth provide additional headroom for data-intensive tasks. The Ryzen 9 also wins the 3DMark 16 Thread test by 26.6%, showing its advantage extends to moderately threaded applications that use a full 16 threads.

The Intel Core i9-9900KS wins in all tests with eight threads or fewer. It takes 3DMark 2 Threads by 14%, 3DMark 4 Threads by 14.7%, and 3DMark 8 Threads by 8.4%. For single-core performance, it is 13.7% faster in 3DMark Single Thread, 10.3% faster in Cinebench R15 Single Core, and 15.2% faster in Geekbench Single Core. This makes it the better choice for gaming, legacy applications, or any software that relies on high clock speeds rather than core count. The Core i9-9900KS's 5.00 GHz boost clock and 8 cores are well-suited to these tasks, and its integration of UHD 630 graphics means it can run with a display even without a discrete GPU. Users who primarily play games or run lightly-threaded productivity apps should favor the Intel part, while those who render or encode should pick the Ryzen 9.