4090 graphics cards came with 24gb of memory. As the AI boom sucked up everything on the market, some modders (mostly in China) learned you could upgrade the VRAM on a 4090 from 24GB to 48GB. These mods were often done poorly and had high failure rates; but people were desperate for more VRAM for AI uses. Soon, better quality modders come online – including these guys in Michigan that seem to be reputable and stand behind their modding.

Still, it’s an odd world. The world is quickly aligning to standards of fitting their models into 32, 96, 128, or 256 of ram – so these 48gb variants might not be as interesting as they once were. Also add to the fact that the processor in the 4090’s isn’t nearly as fast as a 5090, and while expensive, 5090’s are now generally available. Still, someone locally was selling one of these cards recently. (Update: still hasn’t sold in 6 weeks)