user: ### NOW ANSWER:
Question: Which controller is NAND type 25nm MLC-HET with sequential read/write MB/s of 270/210?
Columns: ['Model', 'Codename', 'Capacities (GB)', 'NAND type', 'Interface', 'Form factor', 'Controller', 'Seq. read/write MB/s', 'Rnd 4KB read/write IOPS (K)', 'Introduced']
Types: ['text', 'text', 'text', 'text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['X18-M/X25-M', 'Ephraim', '80/160', '50nm MLC', 'SATA 3 Gbit/s', '1.8"/2.5"', 'Intel', '250 / 70', '35 / 3.300–0.35', 'Sept 2008 (now EOL )']
SQL:

assistant: SELECT "Controller" FROM "Table" WHERE "NAND type" = '25nm MLC-HET' AND "Seq. read/write MB/s" = '270/210';