CPU_VS_GPU / 2026-09-11
Intel Core i5-9400FvsNVIDIA GTX 1070
Complete bottleneck analysis at 1080p, 1440p, Ultrawide (UWQHD/SUWQHD), and 4K with estimated FPS for popular games.
40%
ESTIMATED GPU BOTTLENECK
Your GPU (GTX 1070) severely limits the system at 2560x1440, leaving the Core i5-9400F heavily underused. A faster GPU would improve performance dramatically.
Load estimated by the model, not measured on your PC.
- PROCESSORIntel Core i5-9400F
- GRAPHICSNVIDIA GTX 1070
- MEMORY16GB DDR4/DDR5
- RESOLUTION2560x1440
Average across the demanding titles at 2560x1440.
Average across the competitive titles, where the processor leads.
What the build draws (365 W) plus headroom.
DEEP-DIVE ANALYSIS
GENERATED BY THE ENGINEThis page breaks down, number by number, what happens when you run an Intel Core i5-9400F alongside an NVIDIA GTX 1070. The processor scores 46/100 and the graphics card 13/100 in our model — the interesting part is how they split the workload at each resolution.
Verdict: 1080p is playable, not smooth
The GTX 1070 sets the limit at both ends of the range: a ~12% GPU bottleneck at 1080p that widens to ~70% at 4K. Straight up: this combination does not deliver a steady 60 FPS in AAA games. 1080p at about 36 FPS is the best compromise, and dropping a setting or two — or turning on DLSS/FSR — turns that into a comfortable frame rate.
Resolution reshuffles the priorities. At 1080p the Core i5-9400F's single-thread speed calls the shots; at 4K it's the raw muscle of the GTX 1070 that matters. That shift shows up in the numbers: 88% efficiency at 1080p versus 30% at 4K.
Down to real numbers: In esports titles like Valorant this pair flies — around 275 FPS at 1080p, plenty for a high-refresh monitor. At the other end, a demanding AAA like Alan Wake 2 drops to ~5 FPS at 4K, which is where the GTX 1070's ceiling really shows. Overall, expect about 36 FPS average in AAA games at 1080p and around 13 FPS at 4K.
[CPU] Core i5-9400F
On the CPU side: the Core i5-9400F rates 46/100 for gaming in this model and brings 6 cores and 6 threads. At lower resolutions it's the one setting the pace for the whole system.
[GPU] GTX 1070
The GTX 1070 scores 13/100 on this model's gaming scale. Its 8 GB of GDDR5 set how far it can go on resolution and texture quality before video memory runs short. It draws every pixel, so its weight grows the higher you push the resolution.
On the chemistry of the pair: The processor is considerably newer than the graphics card (3 years), so you have plenty of headroom to drop in a stronger GPU later. You're combining an Intel platform with an NVIDIA GPU — a perfectly valid mix that imposes no penalty.
DO YOU NEED TO CHANGE ANYTHING?
At 1440p the GTX 1070 sets the frame rate. No card in our catalogue clears the bar we use for a recommendation: at least 25% more frames while the Core i5-9400F still keeps it fully fed. The closest, the NVIDIA RTX 5090, adds about 93% in this model. So there is no card we would tell you to buy for this pairing.
PRICE OF EACH PART
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SPECIFICATIONS
CATALOGUE DATA[CPU] Intel Core i5-9400F
- Cores6C / 6T
- Clock2.9 – 4.1 GHz
- TDP65 W
- SocketLGA1151
- Single-thread2,421
- Multi-thread9,457
- L3 cache9 MB
[GPU] NVIDIA GTX 1070
- VRAM8 GB GDDR5
- Memory bus256-bit
- TDP150 W
- G3D Mark13,391
- Memory bandwidth256.3 GB/s
BOTTLENECK BY RESOLUTION
SYNERGY · AVERAGE FPSYour GPU (GTX 1070) is a slight limiting factor at 1920x1080, with limited real-world impact. Most titles will run smoothly.
Your GPU (GTX 1070) severely limits the system at 2560x1440, leaving the Core i5-9400F heavily underused. A faster GPU would improve performance dramatically.
Your GPU (GTX 1070) severely limits the system at 3440x1440 (Ultrawide 21:9), leaving the Core i5-9400F heavily underused. A faster GPU would improve performance dramatically.
Your GPU (GTX 1070) severely limits the system at 5120x1440 (Super Ultrawide 32:9), leaving the Core i5-9400F heavily underused. A faster GPU would improve performance dramatically.
Your GPU (GTX 1070) severely limits the system at 4K, leaving the Core i5-9400F heavily underused. A faster GPU would improve performance dramatically.
ESTIMATED FPS BY GAME
1920x1080SYSTEM DIAGNOSTICS
POWER · VRAM & PCIe · RAMPOWER ESTIMATION
The Core i5-9400F (65W) and GTX 1070 (150W) add up to roughly 215W under load. Adding 150W for the rest of the system gives 365W, and with a 30% transient margin, 550W is the safe figure.
VIDEO MEMORY AND PCIe
The GTX 1070's memory bus (256-bit) and bandwidth (256.3 GB/s) describe its own video memory, meaning how fast the card reads its 8 GB of GDDR5, not the PCIe link to the processor. The PCIe link depends on the card, the processor and the motherboard slot together; our catalogue does not record PCIe generation or lane count, so the model does not estimate it. It matters most for cards with an eight-lane interface in older PCIe 3.0 boards: check the card's and the board's specifications.
SYSTEM MEMORY
This page assumes 16 GB in dual channel. At 1080p, the resolution recommended above, that meets the model's capacity target of 16 GB (enough for three in four of the games it covers), so more capacity would add little or nothing there. The target stays at 16 GB even at 4K, so a larger kit is for heavy multitasking or mods, not for these games. Memory speed and a second channel act on the processor's ceiling instead: they matter in the games the CPU limits, by an amount that depends on the game, and the calculator lets you enter your own kit.
HOW THIS PAGE IS CALCULATED
ENGINE v2026.08 · 2026-09-11CALCULATED, NOT WRITTEN
Every figure and every sentence comes from the same deterministic engine, driven by the catalogue specifications. That is what makes it reproducible: with the same engine version (2026.08) and the same catalogue, the same pairing always gives the same result. When either changes, the version and date above change with it, and the changelog says why.
WHERE THE DATA COMES FROM
Specifications come from the official AMD, Intel and NVIDIA datasheets together with PassMark and TechPowerUp. The gaming indices are calibrated against frame rates published by review outlets (TechPowerUp, TechSpot / Hardware Unboxed, Tom's Hardware, Gamers Nexus, Digital Foundry) rather than synthetic scores. That data is compiled, not measured here: this site runs no test bench of its own.
STATED LIMITS
Figures estimate native raster performance at high/ultra quality, with no ray tracing, upscaling or frame generation. We do not yet publish an externally validated error margin — the accuracy page states exactly where that stands.
* Affiliate disclosure: the Amazon links exist to show pricing. As an Amazon Associate we earn from qualifying purchases at no extra cost to you. Recommendation order is decided by the engine and does not depend on commission.
TRY WITH YOUR OWN HARDWARE
Customize RAM, resolution, and discover upgrade recommendations.
FREQUENTLY ASKED QUESTIONS
5Does the Intel Core i5-9400F bottleneck the NVIDIA GTX 1070?
The GTX 1070 sets the limit at both ends of the range: a ~12% GPU bottleneck at 1080p that widens to ~70% at 4K. Overall, the GPU is the limit at high resolution, with 47% average efficiency across the 12 resolutions our model tests. 1080p is the highest resolution that stays playable, at about 36 FPS on average in AAA titles.
How many FPS do the Core i5-9400F and GTX 1070 get at 1080p?
At 1080p this combination averages about 36 FPS in AAA games and around 161 FPS in esports titles. In Valorant we estimate up to 275 FPS.
Is this pairing good for 4K gaming?
Not for AAA titles at native high settings: about 13 FPS on average at 4K. It would take upscaling, much lower settings or faster hardware.
What power supply do I need for the Core i5-9400F and GTX 1070?
With an estimated combined draw of 215W across CPU and GPU, we recommend at least a 550W 80+ Gold supply (ideally ATX 3.0) to run with headroom.
Is the GTX 1070's 8 GB of VRAM enough?
8 GB falls short at 1440p for 3 of the 11 games the model tracks, and for 6 at 4K. In those titles expect to lower texture settings, or to see frame-time spikes if you do not.