When discussing the largest games for 7.9GB dual-layer DVDs, it's essential to note that both the PS2 and Xbox 360 used different types of discs. The PS2 used DVDs, while the Xbox 360 used a proprietary format called Xbox Game Discs. However, the Xbox 360's standard disc capacity was typically around 7GB for single-layer discs and up to 8.13GB for dual-layer discs (XGD3 format) introduced later in its lifecycle8.
For the PS2, one of the largest games was Gran Turismo 4, which utilized a dual-layer DVD to store over 9GB of data1. However, this exceeds the typical capacity of a dual-layer DVD-R DL, which is generally around 7.7 to 7.9GB when burned4. Other large PS2 games might not have reached this size due to the limitations of standard DVD technology.
For the Xbox 360, games like Tekken Tag Tournament 2 had an optional installation size of 7.9GB, which is typical for the console's standard disc capacity5. However, the Xbox 360's discs were not exactly dual-layer DVDs but rather proprietary formats like XGD2 and XGD3, with the latter allowing up to 8.13GB of data8. Games were generally optimized to fit within these capacities.
In summary, while Gran Turismo 4 for the PS2 is notable for its large size, the Xbox 360's games were typically optimized to fit within the console's disc capacity, with Tekken Tag Tournament 2 being a notable example of a game that could optionally install up to 7.9GB.