Hard Errors are almost always permanent physical faults. They can be shorts or open points, or other defects in the DRAM silicon, or imperfections elsewhere in the BGA package. The hard error might have been originally present in the component when it was released from the manufacturer, or it might have arisen due to aging, electrical or thermal stress. The key aspect of intermittent errors is clear. They are inconsistent. A specific memory location sometimes is correct, but is sometimes incorrect. Errors may be correct at room temperature, but show an increase of error rates at high temperature. Also, some errors occur more often with particular DRAM timing conditions, such as if the length of time that elapses between when a cell is refreshed becomes longer. Soft errors most often occur due to external causes, such as radiation. Some examples of this can be large, strong particles of radiation, or powerful electromagnetic forces. Most often, no damage occurs, so as soon as the cause disappears, errors stop, too.