Nvidia’s RTX 5090 can’t run older games, but this user found an expensive fix

Fans of PhysX on 32-bit CUDA are not ready to let go of the capability for the RTX 5090 GPU. Gamers have become inventive by rigging the already expensive graphics card with additional, compatible GPUs to regain PhysX function on their gaming setups.

Nvidia recently announced that it is halting support for the legacy GPU-accelerated physics simulation technology, PhysX on newer graphics cards. This indicated that many popular older games would not be compatible with the RTX 5090 GPU and beyond in terms of detailed simulation and rendering. Without PhysX support, legacy games perform at significantly lower frame rates and aren’t able to properly execute many particle effects, including moving smoke, cloth, liquids, and shattering glass.

Tom’s Hardware previously noted it was possible to keep PhysX support going on a PC running an RTX 50 series GPU and beyond by pairing it with an RTX 40 series or older graphics card, only tapping the latter component in to work on the Nvidia control panel when necessary. This is exactly what Reddit user, jerubedo did– purchasing an RTX 3050 graphics card to pair with an RTX 5090 GPU. The enthusiast shared their results on the Nvidia forum.

RTX 3050 pairing results

The gamer tested the two GPUs on several legacy games, including Mafia II Classic, Batman Arkham, Borderlands 2, Assassin’s Creed IV: Black Flag, and Mirror’s Edge to varied results. Overall, the test yielded that the PhysX performance on the RTX 5090 GPU suffered without the help of the RTX 3050.

The RTX 5090 ran on its own with significantly low frame rates. With Borderlands 2, the user reported that PhysX would not run at all. Meanwhile, the RTX 5090 run with support from the RTX 3050, experienced much-elevated frame rates and improved support for effects. With Assassin’s Creed IV: Black Flag, the gamer indicated the frame rates were relatively the same between the two setups, at approximately 62fps.

However, other games saw extreme differences. The Redditor reported that Mirror’s Edge saw a frame rate of 12fps without the RTX 3050, with the game pausing for 49 seconds during a scene of glass shattering. In comparison, the RTX 5090 and RTX 3050 pair had a frame rate of 171fps.

No PhysX replacement

Notably, the RTX 5090 retails for approximately $2,000, which is quite costly for a computing component. The GPU is already in limited quantity and high demand, making it even more unfortunate that Nvidia is stripping away long-appreciated functionalities from the graphics system. While purchasing an additional GPU to regain PhysX function is an interesting feat, it’s not a move every enthusiast wants to make when they expect their already expensive components to just work.

The commentators at Digital Foundry podcast noted that without PhysX or a dedicated GPU, the RTX 5090 has essentially lost backward compatibility when running older games. They added that without legacy support, the rendering that used to be run by PhysX is now taken up by aspects of the CPU, which does not function as well. While they would have expected CPU support to have caught up to the decades-old PhysX they don’t find this to be the case– making the retiring for this technology all the more disappointing for many. Additionally, the team noted there doesn’t seem to be any PhysX replacement in the pipeline, suggesting hardware rigging such as jerubedo’s experiment may be fans’ only option to retain the high-end rendering they desire.