Intel Core i5-8400 vs Intel Core i5-9500 Comparison

Where Each One Wins

The recorded benchmark data splits these two six-core processors into distinct roles. The Intel Core i5-9500 takes the majority of wins, 11 out of 19 head-to-head comparisons, while the Intel Core i5-8400 claims 8. The split is not arbitrary. The i5-9500 dominates in workloads that stress memory bandwidth, encryption, floating point, and integer throughput, while the i5-8400 holds a narrow but consistent edge in rendering workloads and physics simulations.

The i5-9500 wins the Geekbench multicore test by 6.2% and the Geekbench singlecore test by 7%. It also leads in PassMark data encryption by 10.7%, floating point math by 8.1%, integer math by 7.8%, and single thread by 8.2%. These are the largest margins in the comparison, and they point to a processor that extracts more performance from identical core and thread counts through higher clocks. The i5-8400, by contrast, wins every Cinebench generation tested: R15, R20, and R23, in both multicore and singlecore variants, with margins of 1.7% to 1.8%. It also wins PassMark physics by 2.5% and find prime numbers by 2.7%.

The pattern suggests the i5-8400 has a slight advantage in sustained rendering loops, while the i5-9500 pulls ahead in bursty, latency-sensitive operations and in workloads that benefit from higher boost clocks. The i5-9500's wins are larger in magnitude than the i5-8400's wins. The largest i5-8400 victory is 1.8%, while the i5-9500 has multiple victories above 7%. This means the i5-9500 is the better overall performer, but the i5-8400 remains competitive in specific rendering scenarios.

Architecture Differences

Both processors share the same fundamental design. They are six-core, six-thread parts built on Intel's 14 nm process, using the Coffee Lake architecture. Both use the Intel Socket 1151, support DDR4 memory in dual-channel configuration, and offer 42.7 GB/s of memory bandwidth. Both have 64 KB of L1 cache per core, 256 KB of L2 cache per core, and 9 MB of shared L3 cache. Neither supports ECC memory, neither has an unlocked multiplier, and both integrate Intel graphics: UHD 630 for the i5-9500 and UHD Graphics 630 for the i5-8400.

The differences are in clocks, release timing, and one physical detail. The i5-9500 has a base clock of 3.00 GHz and a boost clock of 4.30 GHz. The i5-8400 has a base clock of 2.80 GHz and a boost clock of 4.00 GHz. That is a 200 MHz advantage in base clock and a 300 MHz advantage in boost clock for the i5-9500. Both have a 65 W TDP, so the i5-9500 achieves its higher clocks within the same power envelope. The i5-8400 has a recorded die size of 154 mm², while no die size is recorded for the i5-9500. Both are marked as end-of-life production status. The i5-9500 is part of the Coffee Lake Refresh generation, released in October 2018, while the i5-8400 is the original Coffee Lake part, released in October 2017. The i5-8400 has a recorded launch MSRP of $182; the i5-9500 has no launch MSRP recorded in the database.

The process node, foundry, cache hierarchy, memory support, PCIe configuration (Gen 3, 16 lanes from the CPU), and integrated graphics are identical. The practical difference is clock speed and a one-year generational refresh. There is no core count difference, no thread count difference, and no cache capacity difference. The i5-9500 is effectively a higher-clocked revision of the same silicon, with the 200 to 300 MHz clock advantage explaining most of its benchmark lead.

Head-to-Head Benchmarks

The Cinebench results are the i5-8400's territory, and they are consistent across all three versions of the test. In Cinebench R15 multicore, the i5-8400 scores 790 against 776 for the i5-9500, a 1.8% margin. In R15 singlecore, the i5-8400 scores 111 against 109, again 1.8%. In R20 multicore, the i5-8400 scores 3295 against 3236, a 1.8% margin. In R20 singlecore, it scores 464 against 456, a 1.7% margin. In R23 multicore, the i5-8400 scores 7847 against 7705, and in R23 singlecore, it scores 1107 against 1087, both 1.8% margins. These are small but repeatable wins. The i5-8400 also wins PassMark physics with 635 against 619, a 2.5% margin, and find prime numbers with 37 against 36, a 2.7% margin.

The i5-9500 answers with larger margins across the rest of the suite. Geekbench multicore shows 5402 against 5088, a 6.2% win. Geekbench singlecore shows 1448 against 1353, a 7% win. PassMark data compression goes to the i5-9500 at 136283 against 129951, a 4.9% margin. Data encryption is the biggest gap: 3125 against 2824, a 10.7% win for the i5-9500. Extended instructions score 12088 against 11543, a 4.7% margin. Floating point math scores 23788 against 22006, an 8.1% margin. Integer math scores 27574 against 25573, a 7.8% margin. PassMark multithread scores 9826 against 9225, a 6.5% margin. Random string sorting scores 16894 against 15952, a 5.9% margin. Single thread scores 2565 against 2371, an 8.2% margin.

The average benchmark score in the database reflects the overall picture. The i5-9500 has an average score of 13452, while the i5-8400 has 12765. Both sit at the 68th percentile among all CPUs. The nearest rivals for the i5-9500 are the Intel Core 3 N355 at 13492 (0.3% behind the i5-9500), the Intel Core i3-12100F at 13494 (0.3% behind), the Intel Core i7-1250U at 13351 (0.8% ahead), and the Intel Core 5 120UL at 13594 (1% behind). The nearest rivals for the i5-8400 are the Intel Xeon Gold 6348 at 12746 (0.2% ahead), the AMD Ryzen Threadripper 3990X at 12786 (0.2% behind), the Intel Core i3-1210U at 12795 (0.2% behind), and the AMD EPYC 7502 at 12709 (0.4% ahead). In short, the i5-9500 sits in a slightly higher performance tier than the i5-8400, despite both being in the same percentile.

FAQ

Q: Which processor is faster in Cinebench rendering tests?

A: The Intel Core i5-8400 wins all six Cinebench comparisons. In R15, R20, and R23, both multicore and singlecore, the i5-8400 leads by 1.7% to 1.8%. For example, Cinebench R23 multicore scores 7847 for the i5-8400 versus 7705 for the i5-9500.

Q: Where does the Intel Core i5-9500 show its biggest advantage?

A: The largest win for the i5-9500 is in PassMark data encryption, where it scores 3125 against 2824, a 10.7% margin. It also leads by 8.2% in PassMark single thread and 8.1% in floating point math.

Q: Do the two processors have the same core and thread configuration?

A: Yes. Both have 6 cores and 6 threads. They also share the same 14 nm process node, 9 MB of shared L3 cache, 64 KB L1 cache per core, and 256 KB L2 cache per core.

Q: What is the clock speed difference between the two?

A: The i5-9500 has a base clock of 3.00 GHz and a boost clock of 4.30 GHz. The i5-8400 has a base clock of 2.80 GHz and a boost clock of 4.00 GHz. Both have a 65 W TDP.

Q: How do the average benchmark scores compare?

A: The i5-9500 has an average benchmark score of 13452, while the i5-8400 has 12765. Both are at the 68th percentile of all CPUs.

Q: Which processor wins more head-to-head benchmarks?

A: The i5-9500 wins 11 of the 19 head-to-head comparisons. The i5-8400 wins 8.

The Verdict

The data points to the Intel Core i5-9500 as the stronger overall processor. It wins 11 of 19 benchmarks, and its victories are consistently larger than those of the i5-8400. The i5-9500 leads by 10.7% in encryption, 8.2% in single thread, 8.1% in floating point, 7.8% in integer math, 7% in Geekbench singlecore, and 6.5% in multithread. Its average benchmark score of 13452 is about 5.4% higher than the i5-8400's 12765. The higher base and boost clocks, 3.00 GHz and 4.30 GHz versus 2.80 GHz and 4.00 GHz, explain the advantage within the same 65 W TDP and the same 14 nm Coffee Lake architecture.

The Intel Core i5-8400 is not without merit. It wins all Cinebench tests, with margins of 1.7% to 1.8%, and it wins PassMark physics by 2.5% and find prime numbers by 2.7%. For users focused on rendering workloads, the i5-8400 is marginally ahead. But those wins are narrow, and they do not offset the i5-9500's broad lead in general computing, encryption, and math workloads.

The choice depends on the workload. For rendering and physics simulation, the i5-8400 is the better pick by a small margin. For everything else, including single-threaded performance, encryption, compression, and integer math, the i5-9500 is clearly ahead. The i5-9500 also has the advantage of a later release date, October 2018 versus October 2017, as part of the Coffee Lake Refresh. Both processors are end-of-life, so availability is a practical concern, but from a pure performance standpoint, the i5-9500 is the superior part. The i5-8400 remains a capable option for Cinebench-style workloads, but the i5-9500 offers the better balance of speed across the full benchmark suite.