This is true that this line does eminate from the 5VSB line of the
PSU ( avery important area of the
PSU for S3 functionality).
Side note - Systems with poor power supplies with bad 5VSB areas always fail WHQL WLP2.0 testing due to their inability to stably complete S3 functions - so to say - bad
PSU's are oft the cause of bad S3 functionality (along side poor windows install or bad windows maintenance).
CWT320W I am using has a REAL 3 amps of 5VSB.