DRAM Typical Read/Write Speed: 17ns （3000x faster than SSD）
SSD Typical Read/Write Speed: 50us
DRAM limited to 2-D arrays ~16G
SSD 3D-arrays ~2T
every 64ms refresh one time. each refresh takes 3ms (row after row)
DRAM Typical Read/Write Speed: 17ns （3000x faster than SSD）
SSD Typical Read/Write Speed: 50us
DRAM limited to 2-D arrays ~16G
SSD 3D-arrays ~2T
every 64ms refresh one time. each refresh takes 3ms (row after row)
