MSI is the first motherboard manufacturer to support 32GB DDR4 DIMMs on its Z390 motherboards. With the help of a small BIOS update, MSI Z390 motherboard owners can now use up to 128GB of memory in their systems.
Previously, you could only dream of using 128GB of memory on HEDT (High-End Desktop) platforms, such as Intel X299 or AMD X399, making that capability on a mainstream motherboard with only four memory slots an exciting breakthrough. While HEDT motherboards are usually more generous with memory slots (eight as opposed to four), the cost of building a HEDT platform is considerably higher so it might not be for everyone.
There have been efforts to support higher memory capacity on motherboards with limited memory slots, such as the most recent DC (Double Capacity) DIMM standard. However, the proprietary DC DIMM format is a non-JEDEC solution limited to only a handful of Asus Z390 motherboards. MSI's support, on the other hand, complies with JEDEC standards and is available for its complete Z390 motherboard lineup ranging from the entry-level Z390-A Pro that costs $130 to the crème de la crème MEG Z390 Godlike, which carries a ridiculous $570 price tag.
With memory prices how they are right now, it costs a small fortune to build up to 128GB of memory on a Z390 motherboard. Samsung's DDR4-2133 32GB stick, which is the most economical option at the moment, goes for $270. Multiply that by four, and you'll end up spending $1,080 on just memory. Nevertheless, it's comforting to know that the option is there when you need it, particularly if memory pricing continues to fall.