The time a slow cooker needs to create its magic varies based on several factors. When a small roast is involved, such as a nice eye of round, the time changes depending on overall poundage, the temperature range of the cooker and the settings you choose. In general, when talking about this cut of meat and a slow cooker, 4 to 8 hours is a good range to start.
Low and Slow
Slow cookers work at temperatures ranging from 170 to 200 degrees Fahrenheit on the low setting and 280 to 300 F on high. They are designed to maintain a steady simmer for several hours. The constant temperature and lengthy cooking time works wonders on tough muscle meat like the eye of round roast, slowly breaking down the fibers and tissues into fork-tender, stewed meat.
Time to Cook
A 2 1/2- to 4-pound eye of round roast will take 8 to 18 hours to cook when using only the low setting, or about 4 1/2 hours per pound. Use the high setting and cooking time drops to about 1 1/2 hours per pound, or about 4 to 6 hours total. Some cooks will start cooking on high for about an hour to get things started and then drop to the low setting to finish the roast. Always check for a finished temperature of at least 145 F for beef.