http://www.intel.com/content/dam/www/public/us/en/documents/datasheets/4th-gen-core-family-mobile-u-y-processor-lines-vol-1-datasheet.pdf
Section 5.5, Table 23.
For Y processors, 11.5W TDP @ 1.3-1.4 GHz, no SDP.
9.5W TDP @ 800 MHz, with an SDP of either 6W or 4.5W.
Note that the Atom Z3770...