Reconstruction times for a 1 TB sata drive on an almost idle system will be about 10 hours. But system load and configuration will have a significant impact on the reconstruction time. In the very few cases where I had a 1 TB disk failure reconstruction took 20-25 hours.
Since you also notice higher latencies I think you system load normally is already high.
Reconstruction time depends from disk size, RAID group size, RAID settings and workload. For 1TB SATA disk with default RAID group size, default RAID settings, and no other workload present reconstruction time 12 hours!!!