Benchmarking programs indicate that my hard drive is performing slower than expected

Comparing benchmarking programs to performance specifications for hard drives is not a realistic way of determining if a hard drive is performing optimally. Poor or slow performance is usually caused by system configuration issues. It is very rare that the performance issue is directly related to the hard drive. To ensure that the computer system is configured for optimal performance, we recommend checking the following:

  • Test the hard drive with Data Lifeguard Diagnostics

  • Ensure DMA mode is enabled for the hard drive

  • Ensure that the BIOS settings are correct for the hard drive

  • Check that the drive is not running in MS-DOS compatibility mode

  • Replace the IDE, Serial ATA, FireWire, ThunderBolt, or USB cable

  • Defragment the drive

  • If EIDE, remove any other devices on the same data cable

  • Update system Motherboard and Windows drivers for EIDE, Serial ATA, ThunderBolt, and USB.

  • Update the BIOS of the computer or motherboard

There are several myths regarding benchmarking programs and hard drive performance. Most hard drive manufacturers provide three major performance specifications; Maximum Buffer to Host Rate, Maximum Buffer to Disk Rate, and lastly the Implied Speed of the Connection Interface (EIDE, Serial ATA, FireWire 400, FireWire 800, ThunderBolt, USB 1.1, USB 2.0, USB 3.0, USB 3.1). Benchmarking results are very system dependent and the results can vary from system to system. This is why many hard drive manufacturers do not provide a "Sustained Transfer Rate" for hard drives.

To understand each transfer rate, you first must understand how the Drive Buffer works.

Drive Buffer (also known as Cache or drive Memory):The buffer on the hard drive (the buffer of Western Digital hard drives can be 2 MB, 8 MB, 16 MB, 32 MB, 64 MB, 128 MB, 256 MB) acts as a temporary staging area for data that is to be read from or written to the hard drive. Most modern hard drives have intelligent buffer management functionality built into hard drive indicating that the most commonly used data is held in the drive buffer for better performance of data access.

Drive specific performance specifications.

Maximum Buffer to Host Rate: Indicates the maximum rate that data can be transferred from the Buffer memory to the EIDE, Serial ATA, USB, ThunderBold or FireWire bridge (still contained within the physical hard drive). Realistically, this value is reached very seldom during normal computer operations as most data needs to be read/written directly from the platters of the hard drive.

Maximum Buffer to Disk Rate: Indicates the maximum rate that data can be transferred from the Buffer memory to the platters on the hard drive. This value is usually much less than the Maximum Buffer to Host Rate because the data must be written to or read from the rotating platters of the hard drive. Reading and writing data to and from the platters of a hard drive take much longer than reading and writing data to the Buffer (as the Buffer does not use moving parts to read/write data).

Implied Speed of the Connection Interface: There are several interface types for Western Digital hard drives. EIDE, Serial ATA, FireWire 400, FireWire 800, ThunderBolt, USB 1.1, USB 2.0, USB 3.0, USB 3.1. This performance value indicates the Maximum Burst Rate of data traveling through the Interface data cable to and from the hard drive. Under any connection type, the data will transfer much slower than the implied speed of the interface because of many factors including, but not limited to how the hard drive is set up (partitions and type of format), computer hardware, interface type, what function the drive performs (if programs are running from the drive), and the data currently on the drive.

Several independent review websites regularly review and test our hard drives with numerous utilities. These websites include: Tom's Hardware, Extreme Tech Weekly, and Storage Review. Although the systems detailed in these reviews are not the same as yours, the methodology performed is consistent. This provides for accurate comparisons between hard drives. For truly accurate comparative benchmarking results, you can build a like system and compare the results with these review websites.

In case the answer did not answer your question, you can always visit the WD Community for help from WD users.

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