AMD’s WAR on Input Lag
AMD’s first move in the war against input lag was Radeon Anti-Lag. That was back in 2019, and as I showed in my original video covering that, Anti-Lag can make a difference. It isn’t completely night and day, and it depends on the game too, but it doesn’t hurt to turn on, and in that video I saw a 35% reduction in input latency which is a massive difference. Now, AMD has stepped their game up with HYPR-RX. This part in particular is limited to 7000 series GPUs or newer, so I’m using this Asus RX 7600 for my testing. AMD claims that with HYPR-RX you can get 78% more performance, and 54% lower latency. Those are some pretty bold claims, so let’s dive in and see if that’s the case.
HYPR-RX itself isn’t really anything new – it’s basically a one click toggle for Radeon Super Resolution, Radeon Anti-Lag and Radeon Boost. The thing that’s new here is the ability to enable both RSR and Radeon Boost at the same time. That’s the part that’s locked to 7000 series GPUs. The performance benefits of those underlying technologies are what gives you any performance uplift you might be seeing – and those are pretty well documented by people who are better than me at collecting useful data.
There are a couple of things I want to dispel here though, specifically surrounding the input lag figure. Input lag is just the time it takes for an action you input, like left clicking your mouse to fire your gun, to that gun being fired on screen. The lower the latency, the more responsive the game will feel, and the faster you can react to what’s happening in game – it’s often easier to aim too. The thing is, part of that latency is all about how much FPS you are getting – or more specifically how long each frame is taking to render. At, say a stable 165 FPS, you will see a new frame every 6 milliseconds. At 30 FPS though? Yeah that’s more like 33 milliseconds. If we take the two figures AMD presented, 78% more FPS and 54% lower latency, and suppose the starting performance was 60 FPS, well 78% more FPS would be 107 FPS. In frame times, that’s 16.7ms and 9.3ms. That’s already 44% faster latency, just from the FPS improvement. If you add on the anti-lag features it’s pretty reasonable to expect 50% lower latency when you’ve almost doubled the performance. This is a great example of how your performance can make a big difference in your input latency, so for competitive games you’ll definitely want to turn the settings down to both get better outright performance, and help lower your latency!
So if HYPR-RX isn’t anything new, what’s the deal here? Well the secret sauce here is something that ISN’T locked to 7000 series GPUs, which is Radeon Anti-Lag… PLUS! This is an addition to the existing Anti-Lag feature which now uses game-specific tweaks to help lower your latency even more. These are all the supported titles at launch, although it sounds like plenty more titles will be on their way soon. Of course I had to put this to the test, so I’ve picked three games I’ve got some experience in, and can use my Open Source Latency Testing Tool – available at OSRTT.com by the way – to measure. Those being Apex Legends, Overwatch 2 and Fortnite. I’ll start with the latter there.
Fortnite has always been pretty bad for input latency. More recent updates seem to have improved things a bit, with my results coming back at around 32.5 milliseconds average, with a few spiking up to more like 45 to 55 milliseconds. This isn’t too bad, although I’d hope to see more consistency. Turning HYPR-RX on though, which enables Anti-Lag and Anti-Lag+, the average drops to 20 milliseconds. That’s 37% faster – and that isn’t from the frame rate running faster. Both were running at around 150 FPS, so this is a driver and in-engine tweak that is helping cut over 10 milliseconds off of the average input latency. That’s fantastic!
Moving on to Apex Legends, I’m happy to report that at 1440p and high/ultra settings, a 7600 will still run around 170 FPS even with HYPR-RX off. The latency ain’t bad either, with an average of 23 milliseconds of input lag. Admittedly the considerable swinging we’ve got here isn’t the best, but that’s pretty good. Now switching HYPR-RX on, again there wasn’t much if any more performance on tap here which is a little strange, but the latency average does go down – but only by a touch. It drops to 20 milliseconds, down from 23ms. That isn’t world-changing, although lower is better. The trend does show the Anti-Lag+ on results as generally better with occasional higher hiccups, which is promising.
As for Overwatch 2.. Well.. That ran at 25.2 milliseconds with HYPR-RX off, and just 24.9 milliseconds with it on. Yeah, that’s functionally identical. You might make the argument that the anti-lag on results are more consistent – and I’d agree with you there – but it isn’t exactly world-changing performance either. Both settings ran at around 230 FPS or so, so what’s going on here?
Well first you need to understand what these Anti-Lag type features are doing. Anti-lag in itself can’t make the GPU render the frame any faster – that’s what boost, RSR and FSR are there for – so they have to be doing something else. The main aim of these features – both vanilla and spicy Anti-Lag – is to reduce overhead that’s getting in the way of the frame processing inputs. At the driver level, the regular Anti-Lag mode, that might mean trying to queue CPU workloads more efficiently to reduce latency. In games that might be something like discarding partially rendered frames when an input is detected – although to be clear that’s an example I’m making up of something that could help reduce latency, not necessarily what the game engines are doing. Hopefully you get the idea though.
The thing is, that sort of bottlenecking depends a lot on the game, and what hardware you have in your system. Me pairing an RX 7600 with a Ryzen 9 7900X means the CPU isn’t likely to be holding up the GPU very often, and so the results I got here aren’t all that impressive. With the balance the other way, managing the CPUs resources more effectively to let the GPU rip as much as it can is likely to give you a better improvement. Of course, I’d recommend leaving at very least Anti-Lag and Anti-Lag+ on if you’ve got an AMD GPU anyway, as it doesn’t seem to have any major drawbacks, and if it gives you an improvement then that’s great. If it doesn’t, ah well.
As for HYPR-RX, I had a weird bug where I assume due to RSR and boost running at the same time – both affect the render resolution so if they’re fighting over what resolution to use that might explain it – where the visuals would get super low res and it’d run at almost slideshow type performance, then it’d kick back to normal. Of course this is AMD’s drivers to give them some time to cook.
