I took a look at the standard, and it's a 7x44 connector for each channel of memory. That gives 308 connection points, which is slightly more than 288 on a DIMM

I took a look at the standard, and it's a 7x44 connector for each channel of memory. That gives 308 connection points, which is slightly more than 288 on a DIMM. Dual-channel modules (as shown in the article) simply double the number of pins to a 14x44 connector (616 pins)