Ray Tracing vs DLSS: No Competition!

Ever since the arrival of 2018’s RTX 20-series GPUs from Nvidia, there’s been endless hype around their ray tracing features. Welcome to the wonderful world of ray-traced reflections and ever more realistic lighting effects! Marvel at the neon lights bouncing off Cyberpunk 2077’s rain-soaked streets! Admire the glint of a lantern’s flame reflected by the barrel of your Kalash rifle in Metro Exodus Enhanced Edition! You could almost hear the salivating in the gaming press offices.

It looked great in the screenshots. God rays, improved depth of field, richer shadows and highlights. An extra splash of realism that almost justified spending hundreds of dollars to upgrade your graphics card. 

Except the reality doesn’t quite match the hype. That extra level of detail is lost when you’re frantically shooting at moving targets, darting left and right, instead of standing still to admire how a glass surface reflects the ambient light onto a puddle on the floor. The lack of proper RTX support in games didn’t help at launch, although things have gradually improved with more compatible games hitting the market and devs adding features to some older games. Even then, the whole ray-tracing phenomenon just felt a bit flat.

Beauty and the beastly frame rates

For me though, the biggest drawback of ray tracing is the performance hit. When my 970 started to show its age I was persuaded to upgrade to a 2070 Super, a card which I’d expected a lot more from when I fired up Cyberpunk 2077. While the ray tracing looked pretty the frame rate drop was shocking. It was only DLSS that salvaged the situation and even then the ray tracing wasn’t worth the performance hit.

Switching off ray tracing but keeping DLSS enabled was like an epiphany. Suddenly DLSS wasn’t trying to mask ray tracing’s performance penalty. Now it was acting like a free performance boost with barely any reduction in graphical quality. Those four letters were, for me, the most important piece of new technology to have hit the PC gaming market in a long time. 

When I bought my 2070 Super I was expecting a bigger jump in raw performance over my old 970. On those titles that support DLSS (which are more common than those doing a good job of ray tracing), there is a significant boost in frame rates. Nvidia’s Deep Learning Super Sampling (DLSS) may have been intended to make ray tracing a viable option for gamers, off-setting the computational cost, but ditch the ray tracing and you’re left with a system that can deliver significantly higher framerates at bigger resolutions. Cyberpunk, Metro, Hitman – suddenly they went from so-so performance to rock-steady 60 FPS at 1440p.

DLSS allows the graphics card to render each frame at a lower native resolution and use the A.I.-powered Tensor cores in the GPU upscale it to a higher one. So, for a 1440p screen, you’d render at 1080p and let the DLSS technology upscale it to 1440p. The results are almost identical to rendering at native resolution but the performance gains can be as much as 20-25%.  With DLSS, 20-series cards like my own can keep up with the demands of modern gaming and I don’t have to pay extra for the privilege.

An added advantage? If you cap your refresh rates to, say, 60 FPS the GPU is having an easier time of it. That means less electricity is being sucked into your gaming rig. In turn that means less heat output for your case fans to deal with. It also means less pain when it comes to paying your electricity bill!

Bring On DLSS 3

Nvidia’s 40-series cards and their Ada Lovelace architecture introduce the next generation of upscaling tech in the form of DLSS 3. It uses new Frame Generation technology and it’s going to be a huge step forward for PC gaming performance. The fourth generation Tensor cores enable the A.I.-powered algorithm to create entire images from scratch, rather than filling in blanks as the earlier versions did. 

We’re already familiar with the Super Resolution tech that upscales a lower-resolution image to our monitor’s native resolution. Now the A.I. scans two consecutive frames, adds motion vectors to decide which bits of the image are moving and to where and then generates an entirely new image to sit between the two ‘real’ frames. Between Super Resolution and Frame Generation, the A.I. in DLSS 3 is rendering 7 out of 8 pixels in the on-screen image, taking the strain away from the native hardware and providing a potentially huge boost in framerate.

DLSS > Ray Tracing

A huge boost? How huge? Well, I haven’t got first-hand experience but the claims from Nvidia are astonishing. Taking Cyberpunk 2077 as an example, they’ve released footage that shows the average framerate almost triples after enabling DLSS 3. That’s with all the bells and whistles turned on!

Running on the powerhouse RTX 4090m Nvidia claim increases from mid-40 FPS to almost 150 FPS! This makes the upgrade from a 30-series GPU to a 40-series seem like one hell of a leap when compared to the relatively mundane step from the 20-series to the 30-series.

The RTX 4090 is a massively powerful piece of kit even without its A.I. box of tricks but it costs four figures, an insane amount for the average gamer. Those of us with shallower pockets need to keep an eye on the 4060 and 4070 GPUs to see if they return similar increases with DLSS 3, particularly at 1080p and 1440p.

One criticism of the new tech, like a lot of criticism aimed at A.I.-powered images, is that it’s not real. If DLSS 3 creates fake frames between 2 real frames it gives the impression of greater FPS but the extra images aren’t real. They’re best guesses at what might happen in between. 

Does it matter if the extra frames aren’t real if you can’t tell the difference? And does it matter if the card can produce these images faster than the human eye can detect? Isn’t it a good thing that a card equipped with DLSS 3 can produce 60 FPS gaming without stressing the GPU and without requiring a small solar farm to feed its insatiable appetite for power?

Ray Tracing vs DLSS: A Clear Winner!

One thing’s for sure, the stand-out feature of the RTX cards is not the one they were originally sold on. You can take your ray tracing and shove it where the perfectly rendered sun doesn’t shine. Ask me to pick a side in Ray Tracing vs DLSS and I’ll take every bit of DLSS-assisted performance boost you can give me.

Nvidia has only just started with DLSS 3. There’ll be plenty of driver updates to come and we’ll see support for DLSS 3 spreading further into the PC games library. Our games will gradually become more playable, more efficient, and capable of running at higher resolutions on lesser hardware. That ultimately means PC gaming gets cheaper! Surely that’s worth far more than a few shiny reflections on a damp city street?