4-6 500mg tablets within a 24 hour period
On top of that daily use brings it down to 3-5, preferably 4 or less of those a day. And they last less than 6 hours.
The 8h extended release is 650mg a tablet, and you can have 3-4 a day daily. And if you have any experience taking them you can feel the first half of the extended dose wear off before the extended one kicks in, which leads to basically NEEDING 4 a day, and staggered start times.