AMD Ryzen Threadripper 3990X vs Intel Core i5-9400F Comparison

The Intel Core i5-9400F and the AMD Ryzen Threadripper 3990X represent two extreme ends of the desktop processor spectrum. The data shows a 6-core, 6-thread Coffee Lake part from Intel facing off against a 64-core, 128-thread Zen 2 behemoth from AMD. While both share a 68th percentile ranking among all CPUs, their performance profiles could not be more different, with the Threadripper dominating every single benchmark in this comparison.

FAQ

Q: Which processor has more cores and threads?

A: The AMD Ryzen Threadripper 3990X has 64 cores and 128 threads, while the Intel Core i5-9400F has just 6 cores and 6 threads. This is a 58-core and 122-thread difference in favor of the AMD part.

Q: What is the performance gap in multi-core workloads?

A: The Threadripper 3990X wins all multi-core benchmarks by a significant margin. For example, in Cinebench R23 multi-core, the AMD part scores 68124 compared to the Intel's 8040, a delta of -88.2% for the i5-9400F. In Geekbench multi-core, the gap is -75.6%.

Q: Is the Threadripper 3990X also faster in single-core tests?

A: Yes, the data indicates the Threadripper wins all single-core tests as well, though by a smaller margin. In Geekbench single-core, the AMD scores 1472 versus the Intel's 1344, a delta of -8.7%. The gap is larger in Cinebench R23 single-core, where the AMD scores 9617 against the Intel's 1135.

Q: What are the key architectural differences?

A: The i5-9400F uses Intel's 14 nm Coffee Lake architecture with 6 cores, while the 3990X uses AMD's 7 nm Zen 2 architecture with 64 cores. The AMD part also features a much larger 256 MB L3 cache, quad-channel memory, and PCIe Gen 4 with 64 lanes, compared to the Intel's 9 MB L3 cache, dual-channel memory, and PCIe Gen 3 with 16 lanes.

Q: Which processor has a higher boost clock?

A: The AMD Ryzen Threadripper 3990X has a higher boost clock of 4.30 GHz, while the Intel Core i5-9400F boosts up to 4.10 GHz. Both have the same base clock of 2.90 GHz.

Q: What is the production status of each processor?

A: The Intel Core i5-9400F is marked as end-of-life, while the AMD Ryzen Threadripper 3990X is listed as active in production.

Architecture Differences

The architectural divide between these two processors is massive. The Intel Core i5-9400F is built on Intel's 14 nm process node, using the Coffee Lake architecture. It features 6 physical cores and 6 threads, meaning no hyper-threading is enabled. The processor has a 9 MB shared L3 cache, with 64 KB of L1 and 256 KB of L2 per core. It uses a dual-channel memory bus supporting DDR4, providing 42.7 GB/s of bandwidth.

In contrast, the AMD Ryzen Threadripper 3990X is built on TSMC's 7 nm process node, using the Zen 2 architecture codenamed Castle Peak. This is a fundamentally different design with 64 cores and 128 threads, enabled by simultaneous multithreading. The chip contains 30,400 million transistors spread across 8x 74 mm² dies. Its cache hierarchy is dramatically larger, with 256 MB of L3 cache and 512 KB of L2 per core. The Threadripper also uses a quad-channel memory bus, doubling the bandwidth to 102.4 GB/s.

The memory and I/O capabilities diverge sharply. The Intel chip supports PCIe Gen 3 with 16 lanes from the CPU, while the AMD part supports PCIe Gen 4 with 64 lanes. Both processors lack integrated graphics, but the Threadripper has an unlocked multiplier for overclocking, whereas the i5-9400F is locked. The Threadripper's foundry is TSMC, while Intel produces the i5-9400F in-house. The transistor count for the Intel chip is not listed, but the AMD part's 30,400 million transistors highlight the scale difference.

Where Each One Wins

Given the benchmark results, the AMD Ryzen Threadripper 3990X wins in every category tested. There are zero wins for the Intel Core i5-9400F in the head-to-head comparison. The Threadripper's dominance is most pronounced in heavily threaded workloads like Cinebench R23 multi-core, where it scores 68124, an 88.2% advantage over the i5-9400F's 8040.

The use-case split is therefore clear. The Threadripper 3990X is designed for extreme multi-threaded productivity, rendering, scientific computing, and any workload that can leverage 128 threads. Its massive 256 MB L3 cache and 102.4 GB/s memory bandwidth support this mission. The i5-9400F, despite its 68th percentile ranking, is a more modest desktop part suited for general computing, light gaming, and tasks that do not scale beyond 6 threads.

Even in single-core tests, the Threadripper holds the advantage, though the margin is smaller. In Geekbench single-core, the AMD scores 1472 versus the Intel's 1344, an 8.7% difference. This suggests the Zen 2 architecture's IPC advantage outweighs the i5-9400F's simpler design in this comparison. The data shows no scenario where the Intel part is the recommended choice based on performance alone.

Specification Differences

The specification sheet highlights the extreme differences between these two processors. The core count is the most obvious distinction: 6 cores and 6 threads for the Intel versus 64 cores and 128 threads for the AMD. The base clocks are identical at 2.90 GHz, but the boost clocks differ, with the Threadripper reaching 4.30 GHz versus the i5-9400F's 4.10 GHz.

Thermal design power (TDP) scales accordingly. The Intel chip is rated at 65 watts, while the AMD part is rated at 280 watts. The sockets are incompatible: Intel Socket 1151 for the i5-9400F versus AMD Socket TRX4 for the Threadripper. The process node advantage goes to AMD with 7 nm, compared to Intel's 14 nm.

Cache and memory specifications diverge significantly. The L2 cache is 256 KB per core on the Intel and 512 KB per core on the AMD. L3 cache is 9 MB shared versus 256 MB, respectively. Memory support is DDR4 for both, but the bus widths differ: dual-channel for Intel and quad-channel for AMD, yielding 42.7 GB/s versus 102.4 GB/s bandwidth. PCIe support also differs: Gen 3 with 16 lanes versus Gen 4 with 64 lanes. The Threadripper has an unlocked multiplier, while the i5-9400F does not. The release dates are also distinct, with the Intel launching in January 2019 and the AMD in February 2020.

Head-to-Head Benchmarks

The benchmark results paint a picture of complete dominance by the AMD Ryzen Threadripper 3990X. In Cinebench R15 multi-core, the AMD scores 6866 against the Intel's 810, a delta of -88.2% for the i5-9400F. The same delta appears in Cinebench R15 single-core, where the AMD's 969 dwarfs the Intel's 114.

Moving to Cinebench R20, the pattern holds. The AMD scores 28612 in multi-core versus the Intel's 3376, again an 88.2% deficit. In single-core, the AMD's 4039 is nearly 8.5 times the Intel's 476. Cinebench R23 shows the largest absolute gap: 68124 for the AMD versus 8040 for the Intel in multi-core, and 9617 versus 1135 in single-core.

Geekbench results show a slightly narrower margin. In multi-core, the AMD scores 20912 against the Intel's 5106, a delta of -75.6%. This is the smallest percentage gap in multi-core tests, though still a massive 4x advantage. The single-core Geekbench test is the closest comparison in the entire dataset, with the AMD scoring 1472 and the Intel scoring 1344, a delta of only -8.7%.

The data shows a total of 8 wins for the AMD Ryzen Threadripper 3990X and 0 wins for the Intel Core i5-9400F. The average benchmark score for the Intel part is 13041, while the AMD part sits at 12786, which explains why both are in the 68th percentile despite the Threadripper's overwhelming victory in every head-to-head test. The Threadripper's nearest rivals include the Intel Xeon Gold 6348 and AMD EPYC 7502, while the i5-9400F's rivals are more mainstream parts like the Intel Core i7-10750H and Core i5-8500. This contrast in rival pools underscores the fundamentally different market positions of these two processors.