We just got information that the new RD790, RD780 & RX780 chipsets will have a new option in BIOS that will allow to get a few extra performance. This is something like NVIDIA's LinkBoost feature but goes a step further in tweaking.


Feature Options: ON (default) / OFF / Custom
Upon selecting CUSTOM option - 3 options that have no submenus appear (the details listed below are hidden). These options only have two modes ON or OFF. Selecting ON selects ALL functions in that mode.

  • o CPU (ON default /OFF)
  • o XpressRoute (ON default/OFF)
  • o MemBoost (ON default/OFF)



Sub Section Name: CPU (ON / OFF)

  • Function 1: To Maximize CPU performance
  • Detail: Change CPU ClkDivisor to “Divide-by-1” mode
  • Limitation: For Phenom (K10) CPU only


Sub Section Name: XpressRoute (ON / OFF)

  • Function 1: To accelerate transfers of data to and from graphics
  • Detail: Increase PCIE clock for Graphic cards with certain device ids. Internal qualification has been done on R600 and R580+ cards and has shown stability at 150Mhz-160Mhz on the PCIE bus (Gen1). Corner lot testing has shown that 125Mhz should be the recommended default to cover worst case scenarios.
  • Limitation: For RD780 and RD790 only.



  • Function 2: To accelerate transfers of data b/w graphics (most notably in SW CrossFire)
  • Detail: Enable BIOS setting to allow P2P transfers
  • Limitation: For RD780 and RD790 only


  • Function 3: To maximize transfer bandwidth of graphics data with a HT1 CPU
  • Detail: Enable BIOS setting to double pump graphics data across HyperTransport
  • Limitation: For RD780 and RD790 only. For HT1 CPUs only (disable for HT3 CPUs)



Sub Section Name: MemBoost (ON / OFF)

  • Function 1: To accelerate memory bandwidth performance with DDR2-800 or higher DIMMs with K8 CPUs
  • Detail: Alter memory timings for DDR2-800 or higher DIMMs
  • Limitation: For RD780 and RD790 only. For DDR2-800 or higher DIMMS. For K8 CPUs only.


Fine tuning adjustments:
Trc, reduce by 2
Twr, reduce by 2
Trrd, reduce by 1
Tref, 7.8us instead of 3.9us
Twtr, reduce by 1
BankSwizzleMode, Enable
Queue Bypass Max. increase to 7
  • Function 2: Disable DRAM PowerDown mode
  • Detail: Change register to 0
  • Limitation: For RD780 and RD790 only.



  • Function 3: Read Enthusiast DIMMs with multiple SPDs
  • Detail: Read Performance SPD that gives maximum performance
  • Limitation: For RD790 only.



Stay tuned as i will have test to show performance gains

Source: Chilehardware