Samsung SSD 850 EVO TurboWrite SLC Buffer Size Unsurprisingly, TurboWrite is also present in the 850 EVO. The idea of running a small portion of the NAND in SLC mode was nothing new, but it was the first time it truly made sense because the 840 EVO used slower TLC NAND and hence the SLC buffer could provide significant improvements to write performance and user experience. TurboWrite is a feature that Samsung brought to the 840 EVO to increase write performance. It's an interesting choice nevertheless, but I suspect Samsung's packaging technology is advanced and mature enough that it's more cost efficient to use high die count packages and small PCBs instead of larger PCBs with more and less dense NAND packages. The use of octal-die packages is actually true for all capacities. Decoding the part number reveals that the packages are equipped with eight chip enablers (CEs), so a single NAND package is viable since all eight dies can be accessed simultaneously. Interestingly enough, both use octal-die packages, meaning that the 120GB 850 EVO only has a single 128GB (8*16GB) NAND package. The 120GB and 250GB models (above) use a tiny PCB with room for two NAND packages (one on each side).

There are three different PCB designs in the 850 EVO lineup.

Samsung 850 evo ssd drives for mac