Fortnite

The Intel Core i5-9400 is a six-core, six-thread desktop processor based on the Coffee Lake architecture, running on the Intel Socket 1151 platform. It has a base clock of 2.90 GHz and a boost clock of 4.10 GHz, with a 65 W TDP. The chip includes 9 MB of shared L3 cache and 64 KB of L1 and 256 KB of L2 cache per core. In synthetic benchmarks, this CPU scores 6629 points in Cinebench R23 multi-core and 935 points in single-core, along with a Geekbench multi-core score of 5141 and a single-core score of 1389. Its average benchmark score is 2254, placing it at the 47th percentile among all CPUs. The nearest rivals in average score are the Intel Core i7-1068NG7 at 2259 (-0.2% delta), the Intel Core i7-10710U at 2248 (+0.3% delta), the AMD Ryzen 5 PRO 1500 at 2246 (+0.4% delta), and the Intel Core i3-10305 at 2264 (-0.4% delta). This places the i5-9400 in a tight performance cluster where the differences between the four competing chips are under half a percent, indicating that in pure compute tasks, any of these processors will deliver nearly identical results.

In the context of Fortnite, this CPU is the limiting factor at lower resolutions despite the presence of a very powerful GPU. The data shows that at 1080p Low settings, the combo achieves 290 FPS, but this figure drops to 232 FPS at High and 161 FPS at Ultra settings. The pattern of FPS decreasing as settings increase, while the GPU load presumably decreases, suggests the CPU is the bottleneck. The i5-9400's six threads are adequate for modern gaming, but its single-core performance (935 points in Cinebench R23) and the fact that Fortnite is a title that benefits from higher clock speeds and stronger per-core throughput mean that the CPU cannot fully feed the RTX 5080 at lower resolutions. The 47th percentile ranking confirms the CPU is mid-pack in overall compute ability, and in a fast-paced Battle Royale, this translates to a ceiling on achievable frame rates that is well below what the GPU alone could deliver.

FAQ

Q: Is the Intel Core i5-9400 a bottleneck for the RTX 5080 in Fortnite?

A: Yes, the data strongly indicates that the i5-9400 is the limiting component in this pairing. At 1080p Low settings, the combo produces 290 FPS, but at 1080p Ultra, it drops to 161 FPS. If the GPU were the bottleneck, the FPS would remain relatively flat across settings, as the GPU load would be the constraint. Instead, the FPS scales with settings, which is a classic sign of CPU limitation. The i5-9400's 47th percentile ranking and its average benchmark score of 2254, which is nearly identical to the Intel Core i7-1068NG7 (2259, -0.2%), indicate that it lacks the headroom to push frame rates higher.

Q: How does the i5-9400 compare to its nearest CPU rivals in terms of raw performance?

A: The i5-9400 is virtually tied with its closest competitors. Its average benchmark score of 2254 is 0.2% lower than the Intel Core i7-1068NG7 (2259), 0.3% higher than the Intel Core i7-10710U (2248), and 0.4% higher than the AMD Ryzen 5 PRO 1500 (2246). The Intel Core i3-10305 is slightly ahead at 2264, a 0.4% delta. For Fortnite, these differences are negligible, meaning that swapping between these CPUs would not meaningfully change the measured FPS; the bottleneck would remain the same.

Q: What is the best resolution to use with this combo to avoid CPU bottlenecking?

A: The data shows that the higher the resolution, the less the CPU limits the frame rate. At 4K High settings, the combo achieves 82 FPS, while at 1080p High it reaches 232 FPS. The gap between 1440p (155 FPS) and 4K (82 FPS) at High settings is substantial, indicating that at 4K the GPU is doing more work and the CPU has more time to prepare frames. For a smoother experience, 1440p Medium (201 FPS) or 4K Medium (106 FPS) appear to be the sweet spots where the GPU is utilized more effectively, though 4K Ultra (54 FPS) shows the GPU struggling to keep up in the most demanding settings.

Q: Does the RTX 5080's massive performance advantage show up in Fortnite with this CPU?

A: Not fully. The RTX 5080 has an average benchmark score of 56083, placing it at the 87th percentile among all GPUs. It is 0.6% ahead of the AMD Radeon 8060S (55757) and 0.7% ahead of the AMD Radeon RX 6750 GRE 12 GB (55698), but 2.2% behind the AMD Radeon RX 9070 GRE (57367). However, in Fortnite, the i5-9400 prevents the GPU from reaching its full potential. At 1080p Low, the combo hits 290 FPS, which is high, but the GPU could likely push much further if the CPU were faster. The GPU's 56.28 TFLOPS of FP32 performance and 960.0 GB/s memory bandwidth are largely underutilized at 1080p, as the CPU becomes the limiting factor.

Q: How much FPS do you lose by increasing settings from Low to Ultra at each resolution?

A: At 1080p, the drop from Low (290 FPS) to High (232 FPS) is 58 FPS, and from High to Ultra (161 FPS) is another 71 FPS. At 1440p, Low is 250 FPS, High is 155 FPS, and Ultra is 103 FPS, representing a 147 FPS total drop from Low to Ultra. At 4K, Low is 150 FPS, High is 82 FPS, and Ultra is 54 FPS, a 96 FPS total drop. The percentage decrease is largest at 1080p because the CPU bottleneck is most severe there, while at 4K the GPU starts to become more relevant, though it still cannot maintain high frame rates at Ultra.

Q: Is this combo better suited for 1080p high-refresh gaming or 4K gaming?

A: Based on the data, 1440p is the best compromise. At 1080p, the CPU limits the framerate, but the FPS is still very high (290 at Low, 232 at High), so it works for high-refresh monitors, but you are leaving GPU performance on the table. At 4K, the FPS drops significantly, with Ultra at 54 FPS, which is below the threshold for smooth competitive play. At 1440p, you get 250 FPS at Low, 201 FPS at Medium, and 155 FPS at High, which are all playable and show a more balanced load between CPU and GPU. The 4K Medium setting (106 FPS) is also viable for a more immersive experience without dropping too low.

Resolution Scaling

The measured FPS data reveals a clear pattern of resolution scaling that highlights the CPU bottleneck at lower resolutions. At 1080p Low settings, the combo achieves 290 FPS. Moving to 1440p Low, the FPS drops to 250, a decrease of 40 FPS or roughly 14%. At 4K Low, the FPS falls to 150, which is a 100 FPS drop from 1080p Low and a 40% reduction from the 1440p figure. This scaling suggests that as resolution increases, the GPU is being tasked with more pixel work, which relieves some pressure from the CPU, but the CPU still holds back the maximum achievable frame rate.

The scaling behavior changes with settings. At High settings, 1080p yields 232 FPS, 1440p yields 155 FPS (a 33% drop), and 4K yields 82 FPS (a 47% drop from 1440p). At Ultra settings, the pattern is similar: 1080p is 161 FPS, 1440p is 103 FPS, and 4K is 54 FPS. The consistent pattern of FPS dropping by roughly a third when moving from 1080p to 1440p, and then dropping by another 40-50% from 1440p to 4K, indicates that the GPU is becoming the primary constraint at higher resolutions, but the CPU's six threads and 9 MB of cache still cannot keep up with the RTX 5080's raw power at 1080p. The Medium settings data, which includes minimum and maximum FPS values, shows a similar trend: 1080p Medium averages 255 FPS (min 216, max 293), 1440p Medium averages 201 FPS (min 171, max 231), and 4K Medium averages 106 FPS (min 90, max 122). The spread between min and max FPS at 4K Medium (32 FPS) is smaller than at 1080p Medium (77 FPS), suggesting that frame pacing is more consistent at higher resolutions where the CPU is less of a limiting factor.

How This Combo Ranks

The Intel Core i5-9400 and NVIDIA GeForce RTX 5080 combination ranks 510th out of 3700 tested combos in Fortnite. This places it in the top 14% of all system configurations tested for this game. The rank is impressive given the CPU's mid-pack compute performance (47th percentile), which shows that the RTX 5080's strength is enough to push the combo into the upper echelon despite the CPU holding it back. However, it is important to note that the ranking reflects the actual measured performance, which is bottlenecked by the CPU at lower resolutions. The GPU's high percentile (87th) and its nearest rivals (AMD Radeon 8060S at +0.6%, AMD Radeon RX 6750 GRE 12 GB at +0.7%, AMD Radeon Pro W5700X at +2.3%, and AMD Radeon RX 9070 GRE at -2.2%) indicate that the GPU is a top-tier part, but the CPU's limitations cap the combo's potential.

In practical terms, a rank of 510 out of 3700 means this combo is faster than the vast majority of systems tested, but there is a significant gap to the top-ranked configurations, which likely pair the RTX 5080 with a much stronger CPU. The data suggests that the i5-9400 is the weak link, as the GPU alone is capable of far higher frame rates. If this combo were paired with a CPU with better single-core performance, it would likely rank much higher, as the GPU has the headroom to deliver more FPS. The measured FPS figures, particularly at 1080p, are solid but not exceptional, which aligns with the rank.

GPU Role

The NVIDIA GeForce RTX 5080 is a flagship GPU based on the Blackwell 2.0 architecture, manufactured on a 5 nm process at TSMC. It features 10752 shading units, 336 texture mapping units, and 112 raster output units, along with 84 ray tracing cores and 336 tensor cores. The GPU has a base clock of 2295 MHz and a boost clock of 2617 MHz, with memory running at 1875 MHz (30 Gbps effective). It is equipped with 16 GB of GDDR7 memory on a 256-bit bus, providing 960.0 GB/s of bandwidth. The GPU delivers 56.28 TFLOPS of FP32 performance and a texture rate of 879.3 GTexel/s. Its average benchmark score is 56083, placing it at the 87th percentile among all GPUs. The nearest rivals are the AMD Radeon 8060S (55757, +0.6% delta), the AMD Radeon RX 6750 GRE 12 GB (55698, +0.7% delta), the AMD Radeon Pro W5700X (54828, +2.3% delta), and the AMD Radeon RX 9070 GRE (57367, -2.2% delta).

In Fortnite, the RTX 5080's role is to render the game's visuals, and its performance is directly tied to resolution and settings. The GPU's 16 GB of VRAM is more than sufficient for Fortnite, even at 4K Ultra, and the 960.0 GB/s bandwidth ensures textures load quickly. However, the measured FPS shows that the GPU is not the bottleneck at 1080p, where the CPU limits performance to 290 FPS at Low. As resolution increases, the GPU's workload increases, and the FPS drops accordingly. At 4K Ultra, the combo achieves only 54 FPS, which indicates that the GPU is struggling with the most demanding settings at the highest resolution. The GPU's 87th percentile ranking and its benchmark scores (e.g., 36565 in Passmark G3D, 8637 in 3DMark Steel Nomad DX12) confirm it is a top-tier part, but the data shows that its full potential is not realized with this CPU.

Measured FPS Breakdown

The following data is from measured tests of the Intel Core i5-9400 and NVIDIA GeForce RTX 5080 in Fortnite. All figures are average FPS unless otherwise noted.

At 1920x1080 (1080p):

• Low settings: 290 FPS
• Medium settings: 255 FPS (minimum 216, maximum 293)
• High settings: 232 FPS
• Ultra settings: 161 FPS

At 2560x1440 (1440p):

• Low settings: 250 FPS
• Medium settings: 201 FPS (minimum 171, maximum 231)
• High settings: 155 FPS
• Ultra settings: 103 FPS

At 3840x2160 (4K):

• Low settings: 150 FPS
• Medium settings: 106 FPS (minimum 90, maximum 122)
• High settings: 82 FPS
• Ultra settings: 54 FPS

The data shows a clear hierarchy: 1080p Low is the fastest setting at 290 FPS, while 4K Ultra is the slowest at 54 FPS. The Medium settings provide the only min/max data, which reveals that the minimum FPS at 1080p (216) is higher than the average FPS at 1440p High (155) and 4K High (82). This indicates that even in the worst-case frames at 1080p, the system is still faster than the average performance at higher resolutions. The gap between Low and Ultra settings is largest at 1080p (129 FPS difference) and smallest at 4K (96 FPS difference), reinforcing that the CPU is the primary constraint at lower resolutions. At 4K, the GPU's workload is so high that the CPU has more time to catch up, which is why the FPS drop from Low to Ultra is less severe in percentage terms (150 to 54, a 64% drop) compared to 1080p (290 to 161, a 44% drop). Ultimately, this combo is best used at 1440p or 4K with Medium to High settings, where the balance between CPU and GPU allows for frame rates above 100 FPS without sacrificing too much visual quality.