2-8.3 Jfsb2: Ddr Dimm Turbo Mode(Optional) - SOLTEK 85DR2-DC Manual

85DR2-DC / 85DR2-DCL
Further Notes on CPU Overclocking:
1. If you have successfully booted system, with or without CPU overclock,
you still can try another CPU overclock in BIOS Setup. Please enter
BIOS Setup, choose "Frequency/Voltage Control" menu, then configure
the "CPU Clock" item to raise your CPU clock.
2. CPU overclocking should take all components on board into account. If
you fail in BIOS overclocking, you will not be able to restart system. In
such case, Power off system and clear CMOS by JBAT1 and then re-
start your system. And remember to reconfigure whatever should be
reconfigured.
3. If your system is already fixed in a cabinet or case, you may not like to
take the trouble to clear CMOS. Then power on your system with the
power button on the PC case and simultaneously press down the "In-
sert" key on the keyboard until you see the initial bootup screen appear.
And remember you should also enter CMOS BIOS Setup instantly and
choose "Load Optimized Defaults" to restore default BIOS .

2-8.3 JFSB2: DDR DIMM Turbo Mode(Optional)

JFSB2 is a design for raising the DDR DIMM performance
without doing CPU overclock.
1. Read the Identification Legend on the CPU, find the de-
fault (Max) FSB which is provided on the P4 CPU. If this
FSB is divided by 4, the result is the default CPU clock.
With a 133MHz CPU, JFSB2 can raise the DDR DIMM
frequency to 1.33 x 133MHz.
2. Setting JFSB2 to 1-2 closed will set the DDR DIMM to
Auto Select Mode. With this mode, the onboard DDR
DIMM Frequency will take the 133MHz default value.
3. Setting JFSB2 to 2-3 closed will set the DDR DIMM Frequency to Turbo
Mode. With this Turbo Mode, the onboard DDR DIMM Frequency is equal
to 1.33 x CPU Clock (resulting in a DIMM Frequency overclocking).
4. Turbo Mode with a 100MHz CPU is not a workable overclocking be-
cause the resulting frequency is lower than that of DDR DIMM.
5. Turbo Mode with a 133MHz CPU will generate a 1.33 x 133MHz (177MHz)
Frequency to DDR DIMM. However, this frequency will overrun the DDR
266/333 SDRAM. In this case, DDR 266/333 will possibly not boot the
system. Only when DDR 400 SDRAM is on board, will it be able to
accomodate the 1.33x133MHz overclocking and thus gain the DIMM
performance raise.
Note: In "Advanced Chipset Features" of BIOS Setup, there is also a "Turbo
Mode" option with the same function of DIMM Performance Raise. Use
either JFSB2 setting or BIOS to enable the Turbo Mode on DDR DIMM.
28
JFSB2:
DDR DIMM
Turbo Mode
(Optional)
1
(default)
1-2 closed
Auto Select
1
2-3 closed
Turbo Mode
with
133Mhz CPU