EDIT:
there are 2 types of RX 560 card from sapphire:
11267-00 --> 90W edition
11267-01 --> 45W edition
Maybe the SAD edition (the 11267-01) has only 14 compute units...
No, 45W version is the one without external PCI-E connector, so
its restricted to draw max 75W (from board) while 90W one can use
max 150W (75W from motherboard and 75W from PCI-E 6-pin connector)
Radeon RX 560 Radeon RX 460
Shaders 1024 vs 896
Compute Units 16 vs 14
TMUs 64 vs 56