i did that originally, but something is writing to my drives as i can hear them "wake up" every 15 minutes or so. i figured in standby, no programs can access the drives since nothings running.
but i answered my own question. after a few hours of standby i popped the case side and the drives are ice cold and dead...so they must be powered down.
im trying to prevent excess heat buildup on the drives while my case fan is turned down during inactivity (if my cheapo motherboard had a fan controller this wouldnt be an issue). in standby mode, my drives are cold to the touch and my CPU hovers at about 37C....acceptable