AMD RD790, RD780 & RX780 BIOS to feature AutoXpress

Our colleagues from Chile Hardware discovered motherboards based on the AMD RD790, RD780 and RX780 will have a special BIOS option called AutoXpress.

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.

CPU (ON default /OFF)

XpressRoute (ON default/OFF)

MemBoost (ON default/OFF)

CPU (ON / OFF)

Function 1: To Maximize CPU performance

Detail: Change CPU ClkDivisor to "Divide-by-1" mode

Limitation: For Phenom (K10) CPU only

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)

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.

Information on the performance gains will follow soon.