Site icon Libretro

RetroArch 1.7.2 – Released!

RetroArch 1.7.2 has just been released! Grab it here.

This latest version has also been uploaded to the Google Play Store.

If you’d like to show your support, consider donating to us. Check here in order to learn more.

Highlights

Runahead latency reduction – better latency than the real hardware

A visual representation by Durante of how the runahead system works in practice.

This might just be our biggest release yet, thanks in no small part to the new runahead latency reduction system. This feature has already been all the rage over the Internet. Well known people like Durante of DSfix fame praised it and the popular site Ars Technica has dedicated an entire article to this game-changing feature.

We ran an article on this new feature before, and since then, several facts have changed on the ground which bears pointing out. First of all, several performance improvements have been made since. Secondly, the feature has now been enabled for the vast majority of the RetroArch platform ports.

The versions that have this feature enabled and exposed now includes:

Here are some basic things you should know:

How to check the amount of lag frames a game has

RetroArch has the ability to pause a core and advance it frame by frame. Perform the following steps to determine the amount of lag frames of a game:

The number of k presses before you get a reaction should be the number of lag frames you can safely remove with run ahead.

Performance, scalability

So, how well does all this scale? Of course, the more expensive hardware you throw at a latency reduction approach like this the better, but how low can we actually go in terms of specs and still obtain good results? To figure out a basic answer to this question, I decided to test the runahead system on two old game consoles that are not exactly powerhouses at this point. The first of the lot is the Xbox OG, powered by a fairly mundane Pentium 3/Celeron 733MHz CPU. The second is the PlayStation3. Its PPU is roughly equivalent to a Pentium 4 2.4GHz CPU in terms of real-world performance, and even that comparison is probably pushing it. So this is not exactly powerful hardware.

Street Fighter Alpha 3 FBAlpha 2012 No runahead 104fps PS3
Street Fighter Alpha 3 FBAlpha 2012 Runahead – 1 frame 57fps PS3
Mega Man 2 QuickNES No runahead 124fps PS3
Mega Man 2 QuickNES runahead – 1 to 6 frames 124fps PS3
Mega Man 2 Nestopia No runahead 124fps PS3
Mega Man 2 Nestopia Runahead – 1 frame 76fps PS3
Mega Man 2 Nestopia Runahead – 2 frames 54fps PS3
Super Mario World Snes9x 2010 No runahead 113fps PS3
Super Mario World Snes9x 2010 Runahead – 1 frame 78fps PS3
Super Mario World Snes9x 2010 Runahead – 2 frames 65fps PS3
Super Mario World Snes9x 2010 Runahead – 3 frames 56fps PS3
Sonic 1 Genesis Plus GX No runahead 116fps PS3
Sonic 1 Genesis Plus GX Runahead – 1 frame 51fps PS3
Bomberman 94 Mednafen PCE Fast No runahead 124fps PS3
Bomberman 94 Mednafen PCE Fast Runahead – 1 frame 83fps PS3
Bomberman 94 Mednafen PCE Fast Runahead – 2 frames 66fps PS3
Sonic 1 SMS Gearsystem No runahead 120fps PS3
Sonic 1 SMS Gearsystem Runahead – 1 frame 63fps PS3
Sonic 1 SMS Genesis Plus GX Runahead – 1 to 6 frames 124fps PS3
Mega Man 2 QuickNES Runahead – 1 to 6 frames Fullspeed Xbox OG
Mega Man 2 FCEUMM Runahead – 1 frame Fullspeed Xbox OG
Mega Man 2 FCEUMM Runahead – 2 frames Not fullspeed Xbox OG
Sonic 2 Genesis Plus GX No runahead Fullspeed Xbox OG
Sonic 2 Genesis Plus GX Runahead – 1 frame Not fullspeed Xbox OG

We consider any PC from the year 2005/2006 (whether desktop or laptop) to be significantly more powerful than either of those consoles, so these test results bode quite well for the scalability and feasibility of the runahead method.

Features like the runahead system will also naturally increase the demand for ever faster cores so that people on lower specced hardware can use runahead with more frames in advance.

CRT Switch Res – GroovyMAME-like features for 15KHz capable CRT monitors!

Thanks to forum-user Alphanu, RetroArch now has the ability to query cores for their exact video timing data, which can be used to switch to native-resolution, 15 kHz modelines for use with standard-definition CRT TVs.

This is a big step for retro purists, as RetroArch can now output “pixel-perfect” video with accurate timing to compatible displays, even quickly switching between interlaced and non-interlaced modes on the fly.

This capability is currently Windows-only and requires modelines to be created in advance by CRT_EmuDriver or Custom Resolution Utility with a compatible GPU. Linux support is coming soon.

In case you’d like to learn more, follow these links:

Direct3D improvements, additions, and a new Direct3D10 driver

With RetroArch 1.7.1, we really stepped our game up to finally start treating Windows as a first-class citizen platform. You have seen this in the form of dedicated Direct 3D 11/12 video drivers that had the ability to run the same shaders as Vulkan, our new slang shader spec that is made possible by the impressive Khronos/ARM-backed project SPIRV-Cross.

Increased backwards compatibility

Previously, the Direct3D 11 driver required that your graphics card driver supported at least Shader Model 5.0. We have since downgraded this requirement to Shader Model 4.0. As a result, I am now able to use the Direct3D 11 video driver on an old 2010 laptop GPU that only supports Shader Model 4.0 (it’s an ATI Mobility Radeon HD 4300). We also try to support more D3D11 feature levels instead of just defaulting to 11.0.

New Direct3D 10 video driver

On some systems, though, you won’t be able to make use of the Direct3D 11 driver no matter what. One of those systems happened to be another old laptop I had lying around here. This one has a Geforce 9200M GS, and the specs state that it supports up to Direct X 10 and Shader Model 4.0. Direct3D 11 is a no go on this GPU even with the increased backwards compatibility.

It’s for this purpose that me and aliaspider spent some time to finally make the Direct3D 10 driver feature-complete. Direct3D 10 should be available from Windows Vista and up, whereas Direct3D 11 is available from Windows 7 and up. The Direct 3D 10 driver should be feature complete and identical to the Direct3D 11 driver, with the sole exception of hardware rendering contexts not being available right now with Direct3D 10.

Which brings us to the last Direct3D-related subject…

Direct3D-powered libretro cores are now possible!

This feature is easily worth its own article, but since we already covered this before and because 1.7.2 has so many huge features, we will relegate this to a side note. Nevertheless, it is none the less important.

Up until now, if you wanted to use hardware-accelerated 3D rendering in a libretro core, your options were OpenGL and/or Vulkan. There is now a third option – Direct3D 11, and the first libretro core that supports this is the PPSSPP core!

With all these features, we now have everything in place to really do an UWP version of RetroArch justice.

Input remapping system improvements

The input remapping system (available from Quick Menu -> Controls) had many obvious limitations previously. Some of these included:

Most of these restrictions have now been lifted at long last thanks to radius, and the visual representation is also much improved now.

To read more about this, also visit the related forum thread here.

Do note that all your existing remap files are now obsolete, and you should start from scratch. This was a necessary evil unfortunately in order to progress.

Various Quality-Of-Life improvements

We have tried to do various consequential Quality-of-Life improvements for this release:

Exit mobile version