It's possible to pull a pound off a 600 watt light, but it's not easy, and you won't hit that number with that grow, but it has been done. The most important ingredients to hitting that number are strain selection and canopy control. That is assuming all other variables are also good, temps, RH, ventilation, circulation, nutrients, pot size, etc. Strain is important. There are definitely really high yielding strains and low yielding ones, and usually the highest quality strains are not super high yielding. Then you have canopy control. It's vital that you train the plants in some way by either topping, LST, SCROG, or a combination of all of them. You have to get the maximum number of bud sites into the prime high lumen area nearest to the light source. If you grow normally with no training you will have only the main cola in that prime area, the rest of the plant will generally be below it and produce much less. That's why SOG grows yield so well. It's a bunch of small plants, but there is a high number of bud sites in the optimal area close to the bulb. SCROG, LST, SOG, and topping all operate under the same principle.
Here's a pic of a properly done scrog. Notice the nearly perfectly even canopy, that is what you are trying to achieve.