Doom

FAQ

Q: What is the best settings preset for this CPU/GPU combo in Doom at 4K?

A: The measured data shows High settings at 3840x2160 produce an average of 81 FPS, which is comfortably above the 60 FPS threshold for smooth play. Ultra drops to 67 FPS average, while Medium sits at 96 FPS. High is the sweet spot for 4K, offering a 14 FPS improvement over Ultra while remaining well within playable territory.

Q: How does this combo rank against other tested configurations in Doom?

A: This combo ranks 823rd out of 3,712 tested combinations, placing it in the top 22% of all tested systems. While the RTX 4090 is a flagship GPU, the mobile Core Ultra 7 155H processor holds the combo back from top-tier positioning in this specific title.

Q: Is the Intel Core Ultra 7 155H a bottleneck at 1080p?

A: Yes, the data strongly suggests CPU limitation at lower resolutions. At 1920x1080 with Low settings, the combo achieves 316 FPS average, but the gap between Low and Ultra settings (316 vs 190 FPS) indicates the CPU is struggling to feed the RTX 4090 at high frame rates. The 16-core, 22-thread processor with a 3.80 GHz base and 4.80 GHz boost clock appears to be the limiting factor.

Q: What is the FPS difference between 1080p and 4K at High settings?

A: At High settings, the combo delivers 232 FPS at 1920x1080, 150 FPS at 2560x1440, and 81 FPS at 3840x2160. That represents a 65% drop from 1080p to 4K, which is a typical scaling pattern for a GPU-bound scenario at higher resolutions.

Q: Does the RTX 4090's 24 GB of memory matter for Doom?

A: For a 2016 title like Doom, the 24 GB GDDR6X memory and 1.01 TB/s bandwidth are far beyond what the game requires. The data shows no memory-related performance anomalies, and the bottleneck shifts to the CPU at lower resolutions rather than any memory constraint.

Q: Is this combo better suited for 1440p or 4K gaming in Doom?

A: Both are viable. At 2560x1440 with Ultra settings, the combo averages 123 FPS, which is excellent for high-refresh displays. At 4K Ultra, the 67 FPS average is still playable but leaves less headroom. For competitive play, 1440p High at 150 FPS offers a better balance; for visual fidelity, 4K High at 81 FPS is the recommended choice.

How This Combo Ranks

The measured data places this Intel Core Ultra 7 155H + RTX 4090 combination at rank 823 out of 3,712 tested combos for Doom. That is a solid top-quartile position, though not the absolute top tier one might expect from pairing a flagship GPU with a modern mobile processor.

The RTX 4090 alone sits at the 88th percentile among all GPUs, with an average benchmark score of 60,347. Its nearest rivals in the database are the Intel Arc Pro A60 (delta 0%), AMD Radeon Pro Vega 48 (0.3% slower), and AMD Radeon PRO V710 (2.9% slower). This GPU is clearly capable of extreme performance in most scenarios.

The CPU, however, tells a different story. The Core Ultra 7 155H ranks at the 83rd percentile among all CPUs, with an average benchmark score of 32,697. Its nearest rivals — the Intel Core i5-14600T (0% delta), AMD Ryzen AI 7 PRO 360 (0.1% faster), AMD Ryzen 5 7400F (0.2% faster), and AMD Ryzen 7 PRO 6850H (0.4% faster) — are all desktop or high-end mobile parts that perform similarly in synthetic benchmarks.

The 823rd rank out of 3,712 indicates that while this combo is strong, many other CPU/GPU pairings achieve higher frame rates in Doom. The gap between this combo's potential and its actual rank is likely due to the CPU's mobile nature — a 28W TDP part with a 7nm process node that, while capable, cannot sustain the same throughput as higher-power desktop processors when paired with a 450W flagship GPU.

Settings Recommendations

For this specific combo in Doom, the settings choice depends heavily on your target resolution and refresh rate.

At 3840x2160, High settings deliver 81 FPS average, which is the best balance of visual quality and performance. Medium runs at 96 FPS but sacrifices visual fidelity, while Ultra drops to 67 FPS — still playable but with less margin for demanding scenes. Low at 111 FPS is unnecessary at 4K since High already clears 80 FPS.

At 2560x1440, High settings are again the recommended choice. The 150 FPS average is ideal for 144Hz displays, and the jump to Ultra (123 FPS) is not worth the visual difference for most players. Medium at 178 FPS and Low at 204 FPS are options for competitive play, but the CPU begins to limit gains above 150 FPS.

At 1920x1080, the data shows diminishing returns from lower settings. High settings at 232 FPS are already far beyond what most monitors can display. Low at 316 FPS and Medium at 275 FPS offer marginal gains, but the CPU bottleneck becomes apparent — the spread from Low to Ultra (316 to 190 FPS) is narrower than the 1440p spread, indicating the processor is the limiting factor.

The measured data supports High as the universal recommendation across all three resolutions. It provides the best frame rate per visual quality trade-off, and the RTX 4090's headroom means High settings never drop below playable thresholds.

Measured FPS Breakdown

3840x2160 (4K):

• Low: 111 FPS average
• Medium: 96 FPS average, with min 82 FPS and max 111 FPS
• High: 81 FPS average
• Ultra: 67 FPS average

2560x1440 (1440p):

• Low: 204 FPS average
• Medium: 178 FPS average, with min 151 FPS and max 205 FPS
• High: 150 FPS average
• Ultra: 123 FPS average

1920x1080 (1080p):

• Low: 316 FPS average
• Medium: 275 FPS average, with min 234 FPS and max 316 FPS
• High: 232 FPS average
• Ultra: 190 FPS average

The min/max data available for Medium settings across all resolutions shows consistent frame delivery. At 4K Medium, the minimum of 82 FPS is still above 60 FPS, indicating no severe frame drops. At 1440p Medium, the minimum of 151 FPS ensures smooth gameplay even in demanding scenes. At 1080p Medium, the minimum of 234 FPS is exceptionally high.

The progression from Low to Ultra at each resolution follows a predictable pattern, with Ultra typically costing about 40-45% of the Low setting's frame rate. At 4K, Low to Ultra drops from 111 to 67 FPS (a 40% reduction); at 1440p, 204 to 123 FPS (a 40% reduction); at 1080p, 316 to 190 FPS (a 40% reduction). This consistency suggests the GPU is the primary scaling factor across settings at each resolution.

Resolution Scaling

The measured FPS data reveals clear scaling patterns when moving from 1080p to 4K.

At High settings, the combo delivers 232 FPS at 1080p, 150 FPS at 1440p, and 81 FPS at 4K. That is a 35% drop from 1080p to 1440p, and a 65% drop from 1080p to 4K. The scaling from 1440p to 4K (46% reduction) is steeper than from 1080p to 1440p (35% reduction), which is typical for GPU-bound workloads where pixel count increases disproportionately.

At Low settings, the pattern shifts: 316 FPS at 1080p, 204 FPS at 1440p, and 111 FPS at 4K. The drop from 1080p to 1440p is 35%, and from 1080p to 4K is 65% — nearly identical to High settings. This similarity across settings indicates that resolution scaling is consistent regardless of graphical load.

The limiting component analysis is revealing. At 1080p, the CPU's role becomes more pronounced — the Core Ultra 7 155H's 16 cores and 22 threads with a 4.80 GHz boost clock cannot fully saturate the RTX 4090 at low settings. The fact that Low settings only reach 316 FPS (versus what a desktop flagship CPU might achieve) points to CPU limitation.

At 4K, the GPU becomes the bottleneck. The RTX 4090's 82.58 TFLOPS FP32 performance and 1.01 TB/s memory bandwidth are taxed heavily, and the CPU has enough headroom to keep up. This is why the FPS drop from 1080p to 4K is consistent across settings — the GPU is doing the heavy lifting at higher resolutions.

The 24 MB of shared L3 cache and 89.6 GB/s memory bandwidth on the CPU side are sufficient for Doom's demands, but the mobile processor's thermal and power constraints (28W TDP) limit its sustained performance at high frame rates.

CPU Role

The Intel Core Ultra 7 155H is a 16-core, 22-thread mobile processor based on the Meteor Lake architecture, built on a 7nm process. It features a base clock of 3.80 GHz and a boost clock of 4.80 GHz, with 112 KB L1 cache per core, 2 MB L2 cache per core, and 24 MB shared L3 cache.

In Doom, this CPU's role is most evident at 1080p with lower settings. The measured data shows that reducing settings from Ultra to Low at 1920x1080 only increases FPS from 190 to 316 (a 66% improvement), whereas at 4K the same settings change yields 67 to 111 FPS (a 66% improvement). This parallel scaling suggests the CPU is consistently providing the same frame generation ceiling regardless of resolution.

The CPU's single-thread performance, as measured by benchmarks like Cinebench R23 single-core (1,743 points) and PassMark single-thread (3,468 points), is adequate but not exceptional. Doom's engine benefits from strong single-core performance, and the 4.80 GHz boost clock helps, but the mobile processor's power envelope limits sustained boost behavior.

The 28W TDP is a significant constraint. Desktop processors in the same performance class (like the Intel Core i5-14600T, the closest rival at 0% delta) typically have higher sustained power limits. In Doom, this means the CPU can generate high frame rates initially but may throttle during extended gaming sessions, particularly at 1080p where the CPU is the bottleneck.

The 22 threads and 16 cores are more than sufficient for Doom, which is not heavily multithreaded. The data suggests the CPU's single-core performance, not core count, is the limiting factor. The PassMark physics score of 1,727 and multithread score of 24,873 indicate strong overall throughput, but the single-thread score of 3,468 is what matters most for this game.

At 1440p and 4K, the CPU's role diminishes as the GPU takes over. The RTX 4090's massive compute resources — 16,384 shading units, 512 TMUs, and 176 ROPs — dominate performance at higher resolutions. The measured FPS at 4K High (81) is roughly one-third of the 1080p High figure (232), aligning with the GPU's workload scaling rather than CPU limitations.

For builders considering this combo, the data indicates the CPU will not hold back the GPU at 4K, but at 1080p with competitive settings, a desktop CPU with higher single-thread performance would yield better results.