Hotfix to Increase Maximum Transfer Size of Windows 7 SP1 USB Storage Devices to 2MB

Microsoft has released an update to increase the maximum transfer size of USB storage devices in Windows 7 or in Windows Server 2008 R2. According to Microsoft, deploying the KB2581464 hotfix will introduce "a new feature that enables you to update the maximum transfer size of USB storage devices in Windows 7 or in Windows […]

Microsoft has released an update to increase the maximum transfer size of USB storage devices in Windows 7 or in Windows Server 2008 R2. According to Microsoft, deploying the KB2581464 hotfix will introduce "a new feature that enables you to update the maximum transfer size of USB storage devices in Windows 7 or in Windows Server 2008 R2.

After you install this update, you can increase the maximum transfer size from 64 kilobytes (KB) to 2 megabytes (MB) in the Usbstor.sys driver."

"For some USB storage devices, performance can be improved if the maximum transfer size is increased from the default 64 KB. This update supports this change when the hardware vendor provides a device information file (INF) to set this value for the USB storage devices," the software giant said.

To apply this hotfix, you must be running one of the following operating systems:

  • Windows 7
  • Windows 7 Service Pack 1 (SP1)
  • Windows Server 2008 R2
  • Windows Server 2008 R2 Service Pack 1 (SP1)

Microsoft says that you first download the hotfix, then follow the steps under to increase the maximum transfer size of USB storage devices manually:

  • Click Start, type regedit in the Start Search box, and then press Enter.
  • Locate and then click the following registry subkey:
    HKLM\SYSTEM\CurrentControlSet\Control\usbstor\VVVVPPPP
  • Click Edit, point to New, and then click DWORDValue.
  • Type MaximumTransferLength, and then press Enter.vClick Edit, and then click Modify.
  • In the Value data box, type a value to specify the maximum transfer size between 64KB and 2MB. For example, you select Decimal and type a value between 65535 (64K) and 2097120 (2M).
  • Exit Registry Editor.
  • Notes:

    • VVVV represents device descriptor idVendor in hexadecimal.
    • PPPP represents device descriptor idProduct in hexadecimal.

[Source: KB2581464]