A 60-minute television program in standard definition requires about 1GB of storage data. According to hard drive manufacturer Seagate, one of its 1TB DVRs stores about 1,000 hours of standard-definition television. Since a 1TB DVR has about twice the capacity of a 500GB DVR, the 500GB drive would hold about 500 hours of programming. However, Comcast states that its 500GB DVR holds 300 hours of SD programming, so there's no set standard and the actual capacity depends on the specific DVR. High Definition Seagate surmises that HD programming requires up to five times as much storage space as SD programming.