Like it or not, upscaling is a cornerstone of a modern gaming PC. Much to the chagrin of vocal commenters, tools like DLSS and FSR are the backbone of PC gaming today. It's ubiquitous among AAA (and many AA and indie) releases, and essential for feeding the cutting-edge ultra-high refresh rate monitors in the most demanding games. Nvidia claims that over 80% of RTX users turn on DLSS, and even if you believe that metric is hogwash, there’s clearly demand.
Nvidia has been defined more by what DLSS can do than what its silicon can do over the past two generations, and AMD has cut down its lineup of graphics hardware while continuing to double down on FSR. Buy a new AAA game, and there’s almost a guarantee that it will have at least one upscaling feature, and usually multiple.
As GPU features, performance for upscalers is (rightfully) framed around graphics cards , but upscaling has a lot of implications for your CPU, as well. Your GPU takes up much less total render time when the upscaler is turned on, but that also means it needs instructions from your CPU faster. As the resolution drops and your GPU is able to churn through frames, your CPU has to keep it fed. If you push down your upscaler to extreme lows, you can easily run into a complete CPU bottleneck because it just can’t keep pace with the number of frames your GPU is able to render.
That’s the floor, but I wanted to investigate the ceiling. As you climb in resolution with DLSS enabled, at what point does CPU scaling disappear? All but the most CPU-bound games show almost no scaling at native 4K due to the massive workload put on the GPU. But in the age of upscalers, native 4K isn’t the way everyone plays games. According to Nvidia, at least, the vast majority of players don’t play that way, in fact.
That’s what we’re going to look at here, using five recent games from our test suite to see how CPU scaling works with DLSS in the equation. In addition to providing insight into one of the most important tools for modern PC gaming, we’ll also answer the question of how much CPU performance really matters for gaming above 1080p. If this is the way most PC gamers are playing their games — and that seems to be the case — it’s worth looking into. After all, if you assume CPU performance doesn’t matter at 1440p or 4K, you can easily create a bottleneck with DLSS enabled.
We’re mainly concerned with resolution here and how it impacts CPU performance as it goes down. As our testing reveals, however, resolution isn’t the only factor. Upscaling models have some overhead, which seems particularly pronounced with DLSS. We didn’t test FSR, though there’s a good chance we’d see less overhead with older, algorithmic versions of FSR compared to DLSS.
Swipe to scroll horizontally Row 0 - Cell 0 Scale Factor Render Scale Input resolution Output resolution Quality 1.5x 66.7% 1280 x 720 1706 x 960 2560 x 1440 1920 x 1080 2560 x 1440 3840 x 2160 Balanced 1.7x 58% 1129 x 635 1506 x 847 2259 x 1270 1920 x 1080 2560 x 1440 3840 x 2160 Performance 2x 50% 960 x 540 1280 x 720 1920 x 1080 1920 x 1080 2560 x 1440 3840 x 2160 Ultra Performance* 3x 33.3% 640 x 360 854 x 480 1280 x 720 1920 x 1080 2560 x 1440 3840 x 2160
*Optional; not included in every game
The table above illustrates why we’re so concerned with resolution. The highest possible resolution with DLSS turned on — short of native resolution with DLAA — is 1440p. Unless you have a 4K output, turning on DLSS means your internal render resolution is always below 1080p. As resolution drops, your CPU should become the performance bottleneck, and we’re taking a look at how that dynamic plays out in real-world tests here.
Swipe to scroll horizontally CPUs Core i5-14400, Core i7-14700K, Ryzen 5 9600X, Ryzen 5 9850X3D GPU RTX 4080 Super Motherboards MSI MPG Z790 Carbon Wi-Fi (LGA1700), MSI MPG X870E Carbon Wi-Fi (AM5) Cooler Corsair iCue Link H150i Elite Cappalix Storage 2TB Sabrent Rocket 4 Plus RAM 2x16GB G.Skill Trident Z Neo RGB DDR5-6000 PSU MSI MPG A1000GS Game settings Mixture of High/Ultra DLSS settings Quality (66.7%), Performance (50%)
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