Table: amd_chipsets
Columns: model
codename
released
fab_nm
sata
usb_2_0_1_1
usb_3_0
parallel_ata_1
raid
gb_ethernet_mac
package
tdp_w

Question: What is the TDP (w) of the chipset with a codename sb850?
SQL: SELECT COUNT("tdp_w") FROM amd_chipsets WHERE "codename" = 'sb850'