hit counter script
Asus P8P67-M User Manual
  1. Manuals
  2. Brands
  3. Asus Manuals
  4. Motherboard
  5. P8P67-M PRO
  6. User manual
Asus P8P67-M User Manual

Asus P8P67-M User Manual

Hide thumbs Also See for P8P67-M:
Table of Contents

Advertisement

Quick Links

P8P67-M

Advertisement

Table of Contents
loading

Related Manuals for Asus P8P67-M

Summary of Contents for Asus P8P67-M

  • Page 1 P8P67-M...
  • Page 2 Product warranty or service will not be extended if: (1) the product is repaired, modified or altered, unless such repair, modification of alteration is authorized in writing by ASUS; or (2) the serial number of the product is defaced or missing.

  • Page 3: Table Of Contents

    Contents Notices ......................vi Safety information ..................vii About this guide ..................vii P8P67-M specifications summary ............. ix Chapter 1: Product introduction Welcome! ..................1-1 Package contents ................. 1-1 Special features ................1-1 1.3.1 Product highlights ............1-1 1.3.2 Innovative ASUS features ..........1-3 Before you proceed ..............
  • Page 4 Managing and updating your BIOS ..........2-1 2.1.1 ASUS Update utility ............2-1 2.1.2 ASUS EZ Flash 2 ............2-2 2.1.3 ASUS CrashFree BIOS 3 utility ........2-3 2.1.4 ASUS BIOS Updater ............2-4 BIOS setup program ..............2-7 Main menu .................. 2-11 2.3.1 System Language ............2-11...
  • Page 5 Option ROM Messages ..........2-27 2.7.4 Setup Mode ..............2-27 2.7.5 Boot Option Priorities ............ 2-28 2.7.6 Boot Override ..............2-28 Tools menu ................. 2-29 2.8.1 ASUS EZ Flash 2 ............2-29 2.8.2 ASUS O.C. Profile ............2-29 Exit menu ..................2-30...

  • Page 6: Notices

    Complying with the REACH (Registration, Evaluation, Authorisation, and Restriction of Chemicals) regulatory framework, we published the chemical substances in our products at ASUS REACH website at http://csr.asus.com/english/REACH.htm. DO NOT throw the motherboard in municipal waste. This product has been designed to enable proper reuse of parts and recycling.

  • Page 7: Safety Information

    Safety information Electrical safety • To prevent electric shock hazard, disconnect the power cable from the electric outlet before relocating the system. • When adding or removing devices to or from the system, ensure that the power cables for the devices are unplugged before the signal cables are connected. If possible, disconnect all power cables from the existing system before you add a device.

  • Page 8: Conventions Used In This Guide

    Refer to the following sources for additional information and for product and software updates. ASUS websites The ASUS website provides updated information on ASUS hardware and software products. Refer to the ASUS contact information. Optional documentation Your product package may include optional documentation, such as warranty flyers, that may have been added by your dealer.

  • Page 9: P8P67-M Specifications Summary

    Extreme Memory Profile (XMP) ® The maximum 32GB memory capacity can be supported with 8GB or above DIMMs. ASUS will update the memory QVL once the DIMMs are available in the market. ** Hyper DIMM support is subject to the physical characteristics of individual CPUs.
  • Page 10 SFS (Stepless Frequency Selection): overclocking - BCLK/PEG frequency tuning from 80MHz up to 300MHz at features 1MHz increment Overclocking protection: - ASUS C.P.R. (CPU Parameter Recall) ASUS unique 100% All High-quality Conductive Polymer Capacitors features ASUS Turbo V Auto Tuning...
  • Page 11 P8P67-M specifications summary Internal connectors/ 3 x USB 2.0/1.1 connectors support additional 6 USB 2.0/1.1 ports switches 1 x IDE connector 2 x SATA 6Gb/s connectors 4 x SATA 3Gb/s connectors 1 x CPU fan connector 1 x Chassis fan connector...

  • Page 13: Chapter 1: Product Introduction

    ® The motherboard delivers a host of new features and latest technologies, making it another standout in the long line of ASUS quality motherboards! Before you start installing the motherboard, and hardware devices on it, check the items in your package with the list below.
  • Page 14 I/O jacks and notifies users of inappropriate connection, which means there will be no more confusion of Line-in, Line-out, and Mic jacks. ASUS P8P67-M...

  • Page 15: Innovative Asus Features

    Get your system up and running in no time. ASUS TurboV Feel the adrenaline rush of real-time OC-now a reality with the ASUS TurboV. This easy OC tool allows you to overclock without exiting or rebooting the OS; and its user-friendly interface makes overclock with just a few clicks away.

  • Page 16: Asus Mylogo2

    BIOS file using the bundled support DVD or USB flash disk that contains the latest BIOS file. ASUS EZ Flash 2 ASUS EZ Flash 2 is a utility that allows you to update the BIOS without using an OS-based utility. C.P.R. (CPU Parameter Recall) The BIOS C.P.R.

  • Page 17: Before You Proceed

    ErP requires products to meet certain energy efficiency requirements in regards to energy consumptions. This is in line with ASUS vision of creating environment-friendly and energy-efficient products through product design and innovation to reduce carbon footprint of the product and thus mitigate environmental impacts.

  • Page 18: Motherboard Overview

    Screw holes Place six screws into the holes indicated by circles to secure the motherboard to the chassis. Do not overtighten the screws! Doing so can damage the motherboard. Place this side towards the rear of the chassis P8P67-M ASUS P8P67-M...

  • Page 19: Motherboard Layout

    EATX12V USB3_12 DRAM_LED SB_PWR asmedia SPDIF_O2 1042 USB56 F_ESATA3G _USB34 LAN1_USB12 8111E Lithium Cell AUDIO CHA_FAN1 CMOS Power AAFP P8P67-M PCIEX16_1 asmedia PCIEX1_1 VT6308P ASM1083 32Mb Super Intel BIOS ® SATA6G_2 SATA6G_1 PCI1 SATA3G_2 SATA3G_1 SATA3G_4 SATA3G_3 PCIEX16_2 SPDIF_OUT 887-VD2...

  • Page 20: Central Processing Unit (Cpu)

    Contact your retailer immediately if the PnP cap is missing, or if you see any damage to the PnP cap/socket contacts/motherboard components. ASUS will shoulder the cost of repair only if the damage is shipment/transit-related. • Keep the cap after installing the motherboard. ASUS will process Return Merchandise Authorization (RMA) requests only if the motherboard comes with the cap on the LGA1155 socket.
  • Page 21 Lift the load lever in the direction of the arrow until the load plate is completely lifted. Load plate Remove the PnP cap from the CPU socket by lifting the tab only. PnP cap Position the CPU over the socket, ensuring that the gold triangle is on the bottom-left corner of the socket, and CPU notches...
  • Page 22 Close the load plate (A), and then push down the load lever (B), ensuring that the front edge of the load plate slides under the retention knob (C). Insert the load lever under the retention tab. ASUS P8P67-M 1-10...

  • Page 23: Installing The Cpu Heatsink And Fan

    1.6.2 Installing the CPU heatsink and fan The Intel LGA1155 processor requires a specially designed heatsink and fan assembly to ® ensure optimum thermal condition and performance. • When you buy a boxed Intel processor, the package includes the CPU fan and ®...

  • Page 24: Uninstalling The Cpu Heatsink And Fan

    Connect the CPU fan cable to the connector on the motherboard labeled CPU_FAN. CPU_FAN P8P67-M P8P67-M CPU fan connector Do not forget to connect the CPU fan connector! Hardware monitoring errors can occur if you fail to plug this connector.

  • Page 25: System Memory

    DDR2 DIMM socket. DDR3 modules are developed for better performance with less power consumption. The figure illustrates the location of the DDR3 DIMM sockets: Channel Sockets Channel A DIMM_A1 and DIMM_A2 Channel B DIMM_B1 and DIMM_B2 P8P67-M P8P67-M 240-pin DDR3 DIMM sockets 1-13 Chapter 1: Product introduction...

  • Page 26: Memory Configurations

    • The maximum 32GB memory capacity can be supported with 8GB or above DIMMs. ASUS will update the memory QVL once the DIMMs are available in the market. • The default memory operation frequency is dependent on its Serial Presence Detect (SPD), which is the standard way of accessing information from a memory module.
  • Page 27 P8P67-M Motherboard Qualified Vendors Lists (QVL) DDR3-2200(O.C.) MHz capability DIMM socket support (Optional) SS/DS Chip Vendors Part No. Size Brand Chip NO. Timing Voltage G.SKILL F3-17600CL8D-4GBPS(XMP) 4GB(2 x 2GB) DS 8-8-8-24 1.65V • KINGMAX FLKE85F-B8KJAA-FEIS(XMP) 2GB • • Kingmax FLKE85F-B8KHA EEIH(XMP) 4GB(2 x 2GB) DS 1.5V-1.7V •...
  • Page 28 • • Mushkin 998659(XMP) 6GB(3 x 2GB) DS - 9-9-9-24 • • • Mushkin 998659(XMP) 6GB(3 x 2GB) DS - 9-9-9-24 1.5~1.6V • • • PATRIOT PGS34G1600LLKA 4GB(2 x 2GB) DS - 7-7-7-20 1.7V • • • ASUS P8P67-M 1-16...
  • Page 29 DDR3-1333 MHz capability DIMM socket Chip support (Optional) Vendors Part No. Size Chip NO. Timing Voltage Brand AD30908C8D-151C A-Data AD31333001GOU A-Data • • • E0906 A-Data AD31333G001GOU 3GB(3 x 1GB) SS 8-8-8-24 1.65-1.85V • • AD30908C8D-151C A-Data AD31333002GOU A-Data • •...
  • Page 30 8-8-8-24 1.5V • • • TAKEMS TMS2GB364D081-107EY 7-7-7-20 1.5V • • TAKEMS TMS2GB364D081-138EY 8-8-8-24 1.5V • • • TAKEMS TMS2GB364D082-138EW 8-8-8-24 1.5V • • UMAX E41302GP0-73BDB UMAX U2S24D30TP-13 • • • WINTEC 3WVS31333-2G-CNR AMPO AM3420803-13H • • • ASUS P8P67-M 1-18...
  • Page 31 • C*: Supports two pairs of modules inserted into both the blue slots and the black slots as two pairs of dual-channel memory configuration. Visit the ASUS website at www.asus.com for the latest QVL. 1-19 Chapter 1: Product introduction...

  • Page 32: Installing A Dimm

    Press the retaining clip outward to unlock the DIMM. Support the DIMM lightly with your fingers when pressing the retaining clip. The DIMM might get damaged when it flips out with extra force. Remove the DIMM from the socket. ASUS P8P67-M 1-20...

  • Page 33: Expansion Slots

    Expansion slots In the future, you may need to install expansion cards. The following sub-sections describe the slots and the expansion cards that they support. Unplug the power cord before adding or removing expansion cards. Failure to do so may cause you physical injury and damage motherboard components.

  • Page 34: Jumpers

    Normal Clear RTC (Default) P8P67-M Clear RTC RAM To erase the RTC RAM: 1. Turn OFF the computer and unplug the power cord. 2. Move the jumper cap from pins 1-2 (default) to pins 2-3. Keep the cap on pins 2-3 for about 5-10 seconds, then move the cap back to pins 1-2.

  • Page 35: Connectors

    1.10 Connectors 1.10.1 Rear panel connectors 4 5 6 7 PS/2 Mouse port (green). This port is for a PS/2 mouse. USB 2.0 ports 3 and 4. These two 4-pin Universal Serial Bus (USB) ports are for USB 2.0 devices. LAN (RJ-45) port.
  • Page 36 • USB 3.0 devices can only be used as data storage only. • We strongly recommend that you connect USB 3.0 devices to USB 3.0 ports for faster and better performance for your USB 3.0 devices. PS/2 Keyboard port (purple). This port is for a PS/2 keyboard. ASUS P8P67-M 1-24...

  • Page 37: Internal Connectors

    Legacy AC’97 pin definition compliant definition P8P67-M Front panel audio connector • We recommend that you connect a high-definition front panel audio module to this connector to avail of the motherboard’s high-definition audio capability. • If you want to connect a high-definition front panel audio module to this connector, set the Front Panel Type item in the BIOS setup to [HD].
  • Page 38 PRI_EIDE P8P67-M NOTE:Orient the red markings on the IDE ribbon cable to PIN 1. P8P67-M IDE connector If any device jumper is set as “Cable-Select,” ensure that all other device jumpers have the same setting. LPT connector (26-1 pin LPT) The LPT (Line Printing Terminal) connector supports devices such as a printer.
  • Page 39 • If you are uncertain about the minimum power supply requirement for your system, refer to the Recommended Power Supply Wattage Calculator at http://support.asus. com/PowerSupplyCalculator/PSCalculator.aspx?SLanguage=en-us for details. Serial port connector (10-1 pin COM1) This connector is for a serial (COM) port.
  • Page 40 • The CPU_FAN connector supports a CPU fan of maximum 2A (24 W) fan power. • Only the CPU_FAN and CHA_FAN1 connectors support the ASUS Q-Fan 2 feature. • If you install two VGA cards, we recommend that you plug the rear chassis fan cable to the motherboard connector labeled CHA_FAN1 for better thermal environment.
  • Page 41 Gb/s signal cables. SATA6G_2 SATA6G_1 P8P67-M P8P67-M Intel SATA 6.0 Gb/s connectors ® • These connectors are set to [AHCI Mode] by default. If you intend to create a Serial ATA RAID set using these connectors, set the SATA Mode item in the BIOS to [RAID Mode].
  • Page 42 SATA3G_1 SATA3G_4 SATA3G_3 P8P67-M P8P67-M Intel SATA 3.0 Gb/s connectors ® • These connectors are set to [AHCI Mode] by default. If you intend to create a Serial ATA RAID set using these connectors, set the SATA Mode item in the BIOS to [RAID Mode].

  • Page 43: Ieee 1394A Connector

    P8P67-M PIN 1 PIN 1 PIN 1 P8P67-M USB2.0 connectors Never connect a 1394 cable to the USB connectors. Doing so will damage the motherboard! The USB module cable is purchased separately. IEEE 1394a connector (10-1 pin IE1394_1) This connector is for an IEEE 1394a port. Connect the IEEE 1394a module cable to this connector, then install the module to a slot opening at the back of the system chassis.

  • Page 44: System Panel Connector

    IDE_LED PWRSW RESET * Requires an ATX power supply P8P67-M System panel connector • System power LED (2-pin PLED) This 2-pin connector is for the system power LED. Connect the chassis power LED cable to this connector. The system power LED lights up when you turn on the system power, and blinks when the system is in sleep mode.

  • Page 45: Onboard Switches

    If the installed DIMMs still fail to boot after the whole tuning process, the DRAM_LED lights continuously. Replace the DIMMs with ones recommended in the Memory QVL (Qualified Vendors Lists) in this user manual or on the ASUS website at www.asus.com.

  • Page 46: Onboard Leds

    P8P67-M Standby Power Powered Off P8P67-M Onboard LED DRAM LED DRAM LED checks the DRAM in sequence during motherboard booting process. If an error is found , the LED next to the error device will continue lighting until the problem is solved.

  • Page 47: Software Support

    The contents of the Support DVD are subject to change at any time without notice. Visit the ASUS website at www.asus.com for updates. To run the Support DVD Place the Support DVD to the optical drive.
  • Page 48 ASUS P8P67-M 1-36...

  • Page 49: Chapter 2: Bios Information

    BIOS in the future. Copy the original motherboard BIOS using the ASUS Update utility. 2.1.1 ASUS Update utility The ASUS Update is a utility that allows you to manage, save, and update the motherboard BIOS in Windows environment. ®...

  • Page 50: Asus Ez Flash 2

    Follow the onscreen instructions to complete the updating process. 2.1.2 ASUS EZ Flash 2 The ASUS EZ Flash 2 feature allows you to update the BIOS without using an OS-based utility. Before you start using this utility, download the latest BIOS file from the ASUS website at www.asus.com.

  • Page 51: Asus Crashfree Bios 3 Utility

    2.1.3 ASUS CrashFree BIOS 3 utility The ASUS CrashFree BIOS 3 is an auto recovery tool that allows you to restore the BIOS file when it fails or gets corrupted during the updating process. You can restore a corrupted BIOS file using the motherboard support DVD or a USB flash drive that contains the updated BIOS file.

  • Page 52: Asus Bios Updater

    2.1.4 ASUS BIOS Updater The ASUS BIOS Updater allows you to update BIOS in DOS environment. This utility also allows you to copy the current BIOS file that you can use as a backup when the BIOS fails or gets corrupted during the updating process.
  • Page 53 The BIOS Updater backup screen appears indicating the BIOS backup process. When BIOS backup is done, press any key to return to the DOS prompt. ASUSTek BIOS Updater for DOS V1.18 Current ROM Update ROM BOARD: P8P67-M BOARD: Unknown VER: 0221 VER:...
  • Page 54 • Ensure to load the BIOS default settings to ensure system compatibility and stability. Select the Load Optimized Defaults item under the Exit menu. Refer to section 2.9 Exit menu for details. • Ensure to connect all SATA hard disk drives after updating the BIOS file if you have disconnected them. ASUS P8P67-M...

  • Page 55: Bios Setup Program

    • The BIOS setup screens shown in this section are for reference purposes only, and may not exactly match what you see on your screen. • Visit the ASUS website at www.asus.com to download the latest BIOS file for this motherboard.

  • Page 56: Bios Menu Screen

    Power Saving mode Loads optimized default Selects the boot device priority Normal mode ASUS Optimal mode Displays the system properties of the selected mode on the right hand side Selects the boot device priority • The boot device options vary depending on the devices you installed to the system.

  • Page 57: Advanced Mode

    The Advanced Mode provides advanced options for experienced end-users to configure the BIOS settings. The figure below shows an example of the Advanced Mode. Refer to the following sections for the detailed configurations. To access the EZ Mode, click Exit, then select ASUS EZ Mode. Back button Menu items...

  • Page 58: Menu Items

    You cannot select an item that is not user-configurable. A configurable field is highlighted when selected. To change the value of a field, select it and press <Enter> to display a list of options. 2-10 ASUS P8P67-M...

  • Page 59: Main Menu

    Main menu The Main menu screen appears when you enter the Advanced Mode of the BIOS Setup program. The Main menu provides you an overview of the basic system information, and allows you to set the system date, time, language, and security settings. EFI BIOS Utility - Advanced Mode Exit Main...

  • Page 60: Administrator Password

    To clear the user password, follow the same steps as in changing a user password, but press <Enter> when prompted to create/confirm the password. After you clear the password, the User Password item on top of the screen shows Not Installed. 2-12 ASUS P8P67-M...

  • Page 61: Ai Tweaker Menu

    Ai Tweaker menu The Ai Tweaker menu items allow you to configure overclocking-related items. Be cautious when changing the settings of the Ai Tweaker menu items. Incorrect field values can cause the system to malfunction. The configuration options for this section vary depending on the CPU and DIMM model you installed on the motherboard.

  • Page 62: Memory Frequency

    Turbo Mode [Enabled] This item appears only when you set the Enhanced Intel SpeedStep Technology item to [Enabled]. [Enabled] Allows processor cores to run faster than marked frequency in specific conditions. [Disabled] Disables this function. 2-14 ASUS P8P67-M...

  • Page 63: Offset Mode Sign

    The following five items appear only when you set both the Enhanced Intel SpeedStep Technology and Turbo Mode items to [Enabled]. Turbo Ratio [Auto] Allows you to manually adjust the Trubo CPU ratio. [Auto] All Turbo ratio are set by Intel CPU default settings. [Maximum Turbo Ratio setting in OS] All numbers of active cores will be set to one single Turbo ratio in OS.

  • Page 64: Dram Voltage

    Calibration] [75% Calibration] [Full Calibration] The actual performance boost may vary depending on your CPU specification. 2.4.11 CPU Spread Spectrum [Auto] [Auto] Automatic configuration. [Disabled] Enhances the BCLK overclocking ability. [Enabled] Sets to [Enabled] for EMI control. 2-16 ASUS P8P67-M...

  • Page 65: Advanced Menu

    Advanced menu The Advanced menu items allow you to change the settings for the CPU and other system devices. Be cautious when changing the settings of the Advanced menu items. Incorrect field values can cause the system to malfunction. EFI BIOS Utility - Advanced Mode Exit Ai Tweaker Main...

  • Page 66: Cpu Configuration

    Disables this function. Enhanced Intel SpeedStep Technology [Enabled] Allows you to enable or disable the Enhanced Intel SpeedStep Technology (EIST). ® [Disabled] The CPU runs at its default speed. [Enabled] The operating system controls the CPU speed. 2-18 ASUS P8P67-M...

  • Page 67: System Agent Configuration

    Turbo Mode [Enabled] This item appears only when you set the Enhanced Intel SpeedStep Technology item to [Enabled] and allows you to enable or disable the Intel Turbo Mode Technology. ® [Enabled] Allows processor cores to run faster than marked frequency in specific condition.

  • Page 68: Sata Configuration

    USB controller legacy mode is enabled. If no USB device is detected, the legacy USB support is disabled. Legacy USB3.0 Support [Enabled] [Enabled] Enables the support for USB 3.0 devices on legacy operating systems (OS). [Disabled] Disables the function. 2-20 ASUS P8P67-M...

  • Page 69: Onboard Devices Configuration

    XHCI Hand-off [Enabled] This item appears only when you set the Legacy USB3.0 Support item to [Enabled]. [Enabled] Enables the support for operating systems without an XHCI hand-off feature. [Disabled] Disables the function. EHCI Hand-off [Disabled] [Enabled] Enables the support for operating systems without an EHCI hand-off feature.

  • Page 70: Serial Port Configuration

    Device Mode [STD Printer Mode] Allows you to select the Printer Port mode. Configuration options: [STD Printer Mode] [SPP Mode] [EPP-1.9 and SPP Mode] [EPP-1.7 and SPP Mode] [ECP Mode] [ECP and EPP 1.9 Mode] [ECP and EPP 1.7 Mode] 2-22 ASUS P8P67-M...

  • Page 71: Apm

    2.5.8 Restore AC Power Loss [Power Off] [Power On] The system goes into on state after an AC power loss. [Power Off] The system goes into off state after an AC power loss. [Last State] The system goes into either off or on state, whatever the system state was before the AC power loss.

  • Page 72: Monitor Menu

    The onboard hardware monitor automatically detects and displays the CPU, chassis, and power fan speeds in rotations per minute (RPM). If the fan is not connected to the motherboard, the field shows N/A. Select Ignore if you do not wish to display the detected speed. 2-24 ASUS P8P67-M...
  • Page 73 2.6.3 CPU Q-Fan Control [Enabled] [Disabled] Disables the CPU Q-Fan control feature. [Enabled] Enables the CPU Q-Fan control feature. CPU Fan Speed Low Limit [600 RPM] This item appears only when you enable the CPU Q-Fan Control feature and allows you to disable or set the CPU fan warning speed.

  • Page 74: Cpu Voltage, 3.3V Voltage, 5V Voltage, 12V Voltage

    The onboard hardware monitor automatically detects the voltage output through the onboard voltage regulators. Select Ignore if you do not want to detect this item. 2.6.6 Anti Surge Support [Enabled] This item allows you to enable or disable the Anti Surge function. Configuration options: [Disabled] [Enabled] 2-26 ASUS P8P67-M...

  • Page 75: Boot Menu

    [Enabled] Enables the full screen logo display feature. [Disabled] Disables the full screen logo display feature. Set this item to [Enabled] to use the ASUS MyLogo 2™ feature. 2.7.3 Option ROM Messages [Force BIOS] [Force BIOS] The third-party ROM messages will be forced to display during the boot sequence.

  • Page 76: Boot Option Priorities

    • To select the boot device during system startup, press <F8> when ASUS Logo appears. • To access Windows OS in Safe Mode, do any of the following: - Press <F5>...

  • Page 77: Tools Menu

    > ASUS O.C. Profile 2.8.1 ASUS EZ Flash 2 Allows you to run ASUS EZ Flash 2. When you press <Enter>, a confirmation message appears. Use the left/right arrow key to select between [Yes] or [No], then press <Enter> to confirm your choice.

  • Page 78: Exit Menu

    Load Optimized Defaults Save Changes & Reset Discard Changes & Exit ASUS EZ Mode Launch EFI Shell from filesystem device Load Optimized Defaults This option allows you to load the default values for each of the parameters on the Setup menus.

  • Page 79: Asus Contact Information

    +1-510-739-3777 +1-510-608-4555 Web site usa.asus.com Technical Support Telephone +1-812-282-2787 Support fax +1-812-284-0883 Online support support.asus.com ASUS COMPUTER GmbH (Germany and Austria) Address Harkort Str. 21-23, D-40880 Ratingen, Germany +49-2102-959911 Web site www.asus.de Online contact www.asus.de/sales Technical Support Telephone (Component) +49-1805-010923*...

Table of Contents

Save PDF