Testing shows why the Steam Machine’s 8GB of graphics RAM could be a problem

By Valve’s admission, its upcoming Steam Machine desktop isn’t swinging for the fences with its graphical performance. The specs promise decent 1080p-to-1440p performance in most games, with 4K occasionally reachable with assistance from FSR upscaling—about what you’d expect from a box with a modern midrange graphics card in it.

But there’s one spec that has caused some concern among Ars staffers and others with their eyes on the Steam Machine: The GPU comes with just 8GB of dedicated graphics RAM, an amount that is steadily becoming more of a bottleneck for midrange GPUs like AMD’s Radeon RX 7060 and 9060, or Nvidia’s GeForce RTX 4060 or 5060.

In our reviews of these GPUs, we’ve already run into some games where the RAM ceiling limits performance in Windows, especially at 1440p. But we’ve been doing more extensive testing of various GPUs with SteamOS, and we can confirm that in current betas, 8GB GPUs struggle even more on SteamOS than they do running the same games at the same settings in Windows 11.

The good news is that Valve is working on solutions, and having a stable platform like the Steam Machine to aim for should help improve things for other hardware with similar configurations. The bad news is there’s plenty of work left to do.

The numbers

We’ve tested an array of dedicated and integrated Radeon GPUs under SteamOS and Windows, and we’ll share more extensive results in another article soon (along with broader SteamOS-vs-Windows observations). But for our purposes here, the two GPUs that highlight the issues most effectively are the 8GB Radeon RX 7600 and the 16GB Radeon RX 7600 XT.

These dedicated GPUs have the benefit of being nearly identical to what Valve plans to ship in the Steam Machine—32 compute units (CUs) instead of Valve’s 28, but the same RDNA3 architecture. They’re also, most importantly for our purposes, pretty similar to each other—the same physical GPU die, just with slightly higher clock speeds and more RAM for the 7600 XT than for the regular 7600.