Foxconn Q45M - Manual (Page 42)

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PCI doesn't actually care much which addresses are used, but by convention the PC platform
puts them at the top of the 32-bit address space. For many years it wasn't possible or practical
to put that much RAM into a PC. But now it is, so it's up to the memory controller and host
bridge to figure out what to do. Many systems cause that high RAM to simply be ignored,
resulting in the loss of effective RAM. More complex systems will take the RAM that would
occupy that 3.5-4GB address space and re-map it into the 4.0-4.5 address space. The RAM
doesn't care because it's just an array of storage cells, it's up to the memory controller to as-
sociate addresses with those storage cells.
Of course, that only works if you're using a 64-bit (or 32bit physical address extension (PAE)
enabled) OS that can deal with physical addresses larger than 32 bits.
Once this option is enabled, the BIOS can see 4096MB of memory.
► Memory Frequency (Available when Intel® Management Engine function is disabled)
This item is used to select memory frequency. Options are: [Auto], [667 MHz] and [800 MHz].
► Memory Timing By (Available when Intel® Management Engine function is disabled)
This item is used to select the provision of DRAM timing by SPD device. The Serial Presence
Detect (SPD) device is a small EEPROM chip, mounted on a memory module. It contains
important information about the module's speed, size, addressing mode and various other pa-
rameters, so that the motherboard memory controller (chipset) can better access the memory.
When “Memory Timing By” is set to [Setup], the following four items will appear:
► CAS# Latency(tCL)
This item dispalys the CAS Latency time. The CAS Latency is the number of clock cycles that
elapse from the time the request for data is sent to the actual memory location until the data is
transmitted from the module.
► RAS# Active Time(tRAS)
This item dispalys the precharge delay time (in clock cycles).
► Row Precharge Time(tRP)
This item dispalys the DRAM RAS precharge time (in clock cycles).
► RAS# to CAS# Delay(tRCD)
This item dispalys the delay time (in clock cycles) between the CAS and RAS strobe signals.
► IGD Memory
This item is used to select the IGD(Integrated Graphics Device) share memory size. Default
value is [32MB].
► DVMT Memory
This item is used to select the DVMT(Dynamic Video Memory Technology) mode memory size
or the FIXED mode memory size used by internal graphics device. Default value is [256MB].
► PCI Express X16 Port
This item is used to enable or disable the PCI Express X16 port.
► Initial Graphic Adapter
This item is used to select which graphics controller is used as the primary boot device.
► VT-d
This item is used to enable or disable VT-d (Intel ® Virtualization Technology for Directed I/O).
Intel ® Virtualization Technology for Directed I/O (VT-d) extends Intel’s Virtualization Technology
(VT) roadmap by providing hardware assists for virtualization solution. VT-d continues from the
existing support for IA-32 (VT-x) and Itanium
® processor (VT-i) virtualization adding new sup-
port for I/O-device virtualization.
Intel VT-d can help end users improve security and reliability of the systems and also improve