Owners of the new NVIDIA GTX 970 graphics card have been complaining that it doesn’t seem to be using any more than 3.5GB of available memory when playing games at Quad-HD or 4K resolutions, which is lower than the 4GB of VRAM that NVIDIA claimed the card comes with.
NVIDIA mentions in the official spec-sheet that the GTX 970 comes with 4GB of VRAM, which is why owners didn’t expect the card to run out of memory when playing games at high resolutions. While not most games will make use of more than 3GB VRAM, some games that do and in those games the performance degrades when they require more than the 3.5GB VRAM that the GTX 970 can use.
According to NVIDIA, the whole issue is due to a miscommunication between various departments regarding the GTX 970 architecture. The GTX 970 doesn’t come with the same ROPs and L2 cache as the flagship GTX 980 card. The GTX 970 comes with 56 ROPs and a maximum 1792KB of L2 cache. In comparison, the GTX 980 card comes with 64 ROPs and 2048KB L2 cache. It is due to the reduced ROPs over the GTX 980 that the GTX 970 memory subsystem cannot handle more than 3.5GB VRAM at once. The 4GB of VRAM that the GTX 970 comes with is split into two different segments of 3.5GB and 512MB each. For most games, the card only uses the 3.5GB segment that also happens to be much faster. The slower 512MB segment is used only when a game requires more than 3.5GB of memory. However, since the secondary memory segment is slower, it results in a performance loss.
Meanwhile, owners of the GTX 970 graphics card aren’t too happy with the disparity in claimed memory and actual performance, having started an online petition against NVIDIA to claim a refund for their GTX 970. The petition has been signed by over 2,900 users so far.