Real time performance
On this page, the amount of transferred (read and written) data are displayed both in the current session and since installation. By using this, the daily average write and read amount values are displayed also.
Hard Disk Sentinel continuously monitors the current write and read speeds and it checks how the current usage is stressing for the hard disk. This is displayed in a percentage (%) value, just like the user can examine the CPU usage in the task manager.
When Hard Disk Sentinel detects a write operation, a red “led” and the current write speed are displayed. In case of a read operation the read speed and a green “led” are displayed. Of course these colors are independent from the hard disk health status.
Based on the current transfer rate and the current disk usage the application estimates a possible (theoretical) maximum transfer rate, which may be reached as a peak transfer rate for a short time. This value is calculated by this formula: (estimated max. transfer rate) = (current transfer rate) / (current disk usage %). For example, if the disk is transferring data with 20 MB/sec and the current disk usage is 50%, then the estimated maximum transfer rate is 40 MB/sec. To increase precision, the values calculated by low disk usage are automatically ignored. This is a theoretical maximum value, some devices, caches or other applications may affect this value.
The current disk transfer rate and the disk usage graphs can be useful in many cases. For example:
When using two or more hard disks, it can be examined which disks are active and which speed they are operating. Eg. if the system is installed on the first hard disk and the other hard disk(s) have an application which generates huge traffic, the disk usage for the application can be checked easily. During a constant load, the current usage of the system hard disk can be also examined, revealing too much virtual memory usage.
During a copy between two different hard disks. The transfer rate and speed of the two disks can be compared and this may reveal which drive is slower than the other.
During burning data to optical storage: to verify the real data transfer rate (burn speed) and to check how big the disk usage is. Lower disk usage means that a higher burning speed can be selected.
On a server (file or database server with huge load) it is possible to examine the usage and the transfer rate of the disk(s). This will help the administrator to decide if a new (faster) hard disk is required in case of adding new clients.
If during a constant speed operation (for example burning to DVD) the disk usage is constantly rising and falling (there are many spikes in the graph), the data on the hard disk may be very fragmented and defragmentation is recommended. (also too high virtual memory usage may cause this problem).
Note: the real time performance monitoring depends on the current operating system. It is not available under Windows 95/98/ME. On some external disks (for example, pendrive or memory card) this function is not supported.