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One of
the questions I get asked a lot is what BIOS settings should I use?
There is not hard and fast rule to this, and to be truthful, there
is a slight misconception that BIOS tweaking will solve all your
stability problems.
The truth
is that while the BIOS can certainly help in matters of system stability,
crashes occuring due to overclocking tend to be caused by memory,
peripherals or the Level 2 cache on the CPU itself.
With
that said, they are certain things you can do to improve things.
So, by
popular demand here are the settings I use - don't forget all systems
are different, and your mileage (and you BIOS depending on your
board type and BIOS revision) will vary!!
BX6 Softmenu:
Recommend
settings for Klamath Class CPU's - The L2 cache on Klamath is
only rated to run up to 333Mhz.
| CPU Operating Speed |
User Define |
| |
|
| - External Clock |
83Mhz |
| - Multiplier Factor |
x4 |
| - AGP/CLK |
2/3 |
| Speed Hold Error |
Disabled |
| |
|
| |
|
| CPU Power Supply |
User Define |
| - Core Voltage |
2.90v |
Recommend settings
for Celeron 300a @ 4.5 x 103
| CPU Operating Speed |
User Define |
| |
|
| Turbo Frequency |
Enabled |
| - External Clock |
100Mhz |
| - Multiplier Factor |
x4.5 |
| - AGP/CLK |
2/3 |
| Speed Hold Error |
Disabled |
| |
|
| |
|
| CPU Power Supply |
User Define |
| - Core Voltage |
2.1v |
Turbo Frequency
only appears at 66 and 100 Mhz and
gives 68.5 and 103Mhz speeds when selected.
Recommend
settings for Celeron 266 @ 4 x 112
| CPU Operating Speed |
User Define |
| |
|
| - External Clock |
112Mhz |
| - Multiplier Factor |
x4 |
| - AGP/CLK |
2/3 |
| Speed Hold Error |
Disabled |
| |
|
| |
|
| CPU Power Supply |
User Define |
| - Core Voltage |
2.2v |
Recommend settings
for P2-333 @ 4 x 100
| CPU Operating Speed |
User Define |
| |
|
| Turbo Frequency |
Disabled |
| - External Clock |
100Mhz |
| - Multiplier Factor |
x4 |
| - AGP/CLK |
2/3 |
| Speed Hold Error |
Disabled |
| |
|
| |
|
| CPU Power Supply |
User Define |
| - Core Voltage |
2.1v |
The above are just examples but can easily be adapted
to other processors and speeds.
Note: AGP/CLK speed is only applicable to AGP cards. Most AGP
cards will not run at 1/1. G200 will run at 1/1 up to 112Mhz. See table.
BH6 Softmenu:
Recommend settings for Klamath Class CPU's - The L2 cache on Klamath is only rated to run up to 333Mhz.
| CPU Operating Speed |
User Define |
| |
|
| - External Clock |
83Mhz |
| - Multiplier Factor |
x4 |
| - AGP/CLK |
2/3 |
| - SEL 100/66# |
High |
| Speed Hold Error |
Disabled |
| |
|
| |
|
| CPU Power Supply |
CPU Default |
| - Core Voltage |
2.8 v |
Recommend settings for Celeron 300a @ 4.5 x 103
| CPU Operating Speed |
User Define |
| |
|
| Turbo Frequency |
Enabled |
| - External Clock |
100Mhz |
| - Multiplier Factor |
x4.5 |
| - AGP/CLK |
2/3 |
| - SEL 100/66# |
High |
| Speed Hold Error |
Disabled |
| |
|
| |
|
| CPU Power Supply |
CPU Default |
| - Core Voltage |
2.1v |
Recommend settings for Celeron 266 @ 4 x 112
| CPU Operating Speed |
User Define |
| |
|
| Turbo Frequency |
Enabled |
| - External Clock |
112Mhz |
| - Multiplier Factor |
x4 |
| - AGP/CLK |
2/3 |
| - SEL 100/66# |
High |
| Speed Hold Error |
Disabled |
| |
|
| |
|
| CPU Power Supply |
CPU Default |
| - Core Voltage |
2.2v |
Recommend settings for P2-333 @ 4 x 100
| CPU Operating Speed |
User Define |
| |
|
| Turbo Frequency |
Disabled |
| - External Clock |
100Mhz |
| - Multiplier Factor |
x4 |
| - AGP/CLK |
2/3 |
| - SEL 100/66# |
High |
| Speed Hold Error |
Disabled |
| |
|
| |
|
| CPU Power Supply |
CPU Default |
| - Core Voltage |
2.2v |
The above are just examples but can easily be adapted
to other processors and speeds.
Notes:
- AGP/CLK speed is only applicable
to AGP cards. Most AGP cards will not run at 1/1. Matrox G200 will run at
1/1 up to 112Mhz
When you set
up your system among other things you may be able determine the
speed of you AGP clock.
Note: The AGP
clock is related to the external clock of your CPU, not the PCI
clock.
| Bus
Speed |
AGP/CLK
setting |
AGP
speed |
| 66
Mhz |
N/A |
66 Mhz |
| 75
Mhz |
N/A |
75 Mhz |
| 83
Mhz |
N/A |
83 Mhz |
| 100mhz |
1/1 |
100 MHz |
| 100mhz |
2/3 |
66.6 MHz |
| 112mhz |
1/1 |
112 MHz |
| 112mhz |
2/3 |
74 MHz |
| 124mhz |
1/1 |
124 Mhz |
| 124mhz |
2/3 |
82 Mhz |
| 133mhz |
1/1 |
133 Mhz |
| 133mhz |
2/3 |
88 Mhz |
Note AGP/CLK does not affect PCI speed.
| Bus Speed |
PCI speed |
| 66 MHz |
33 MHz |
| 68 MHz* |
34 MHz |
| 75 MHz |
37.5 MHz |
| 83 MHz |
41.5 MHz |
| 100 MHz |
33 MHz |
| 103 MHz* |
34 MHz |
| 112 MHz |
37 MHz |
| 124 Mhz |
41 Mhz |
| 133 MHz |
44 MHz (/4 PCI divider runs
at 33 Mhz) |
*turbo setting
- SEL100/66# unlocks hidden multipliers on Pentium2 350/400 only!! This
switch, which toggles to High or Low enables
multipliers of up to 5x on these CPU's.
| SDRAM CAS Latency Time |
2 |
| SDRAM Precharge |
Disabled |
| DRAM Data Integrity Mode |
Non-ECC |
| System BIOS Cacheable |
Enabled |
| Video BIOS Cacheable |
Enabled |
| Video RAM Cacheable |
Disabled |
| 8 Bit I/O Recovery Time |
1 |
| 16 Bit I/O Recovery Time |
1 |
| Memory Hole at 15M-16M |
Disabled |
| Passive Release |
Enabled |
| Delayed Transaction |
Enabled |
| AGP Aperture Size(MB) |
64 |
| Spread Spectrum Modulation |
Disabled |
Notes:
- Setting 8/16 Bit I/O Recovery
Time to 2 / 4 or greater can solve some keyboard / ISA problems.
- SDRAM CAS Latency Time should
be set to 3 for 133Mhz bus speed. A setting of 3 can also enable PC66 SDRAM to run at 100,103 and 112 Mhz bus speed.
If in doubt, always select 3.
- DRAM Data Integrity Mode: Setting
this to non-ECC can speed up systems with ECC RAM slightly at the expense of data integrity.
- Video BIOS Cacheable: Should
normally be enabled, but some cards, notably the Riva128 should run disabled. If in doubt contact your video board
manufacturer.
- SDRAM Precharge can increase performance with some
SDRAM.
| CPU Level1 Cache |
Enabled |
| CPU Level2 Cache |
Enabled |
| CPU L2 Cache ECC Checking |
Disabled |
Notes:
- Disabling CPU Level2 Cache can enable the running
of higher speeds i.e P2-333 up to 4 x 112 rather than 4 x 103. The speed hit however does not compensate for the
higher speed in Mhz.
- CPU L2 Cache ECC Checking will
enable or disable ECC onboard chance(only the P2-300 or higher has this, apart from a few P2-266's). Disabling
this will increase performance, with a possible loss of stabiliy.
| Force Update ESCD |
Disabled |
| PnP OS Installed |
No |
| Resources Controlled by |
Manual |
|
** IRQ DMA Assign to PnP / ISA PnP **
|
| IRQ 3 : N |
IRQ 4 : N |
IRQ 5 : Y |
IRQ 7 : N |
| IRQ 9 : Y |
IRQ 10 : Y |
IRQ 11 : Y |
IRQ 12 : Y |
| IRQ 14 : N |
IRQ 15 : N |
DMA 0 : Y |
DMA 1 : Y |
| DMA 2 : Y |
DMA 3 : Y |
DMA 4 : Y |
DMA 5 : Y |
| Assign IRQ For VGA |
Auto |
| PCI IDE Card 2nd Channel |
Disabled |
| PCI IDE Card Map To |
ISA |
| |
|
| Onboard IDE Controller |
Enabled |
| -Master Drive Mode: |
Auto |
| -Slave Drive Mode: |
PIO mode 4 |
Notes:
- PnP OS Installed: No can solve some ISA card problems. Also note the
PCI IDE card settings.
- To use Resources Controlled by, select Manual
and move the cursor to the bottom or top of the screen. Your cursor will then appear within the IRQ/DMA resources
which can then be set to either Y or N with Page Up or Page Down. This is useful for configuring
legacy ISA (non-plug and play) devices.
- Setting Force Update ESCD
to enabled forces the BIOS to clear Plug and Play information.
- The example for Slave Drive Mode:PIO mode 4
is useful for solving booting lockups for hard drives that do not like 83/112/124
and 133 bus speeds.
- Setting Onboard IDE Controller
to Disabled will free up IRQ 14 and 15 on all SCSI (non-ide) systems
| Power Management |
User Define |
| PM Control by APM |
Yes |
| Video Off Method |
DPMS |
| Video Off After |
Standby |
| CPU Fan Off Option |
Always On |
| Modem Use IRQ |
NA |
| |
|
| Doze Mode |
Disable |
| Standby Mode |
Disable |
| Suspend Mode |
Disable |
| IDE HDD Power Down |
Disable |
| Throttle Duty Cycle |
50.0% |
| Power Button Override |
Enabled |
| Resume by LAN |
Disabled |
| Power On by Ring |
Disabled |
| Power On by Ring |
Disabled |
See the FAQ for more information on Power Management.
Power Management enabled will generally result in slightly reduced performance.
Summary:
The main settings that can aid stability are:
SDRAM CAS Latency Time:
Setting this to 3 will slow down your RAM slightly. You will not notice a performance
hit!!
SDRAM RAS-to-CAS Delay:
Memory can be viewed as a "grid" with rows and columns. There is a small delay necessary when changing from one Row to the next column. Normally this should be set to 3, but good RAM will run just fine at a delay or 2. Setting to 2 will give a very small performance boost.
SDRAM RAS Precharge Time:
As above, when addressing a new row, a small delay is necessary. Settings of either 2 or 3 are applicable, with a setting of 2 being slightly faster than 3.
Auto Detect DIMM/PCI Slot
This setting will turn off any DIMM or PCI slots not in use. It has no impact on performance.
Core Voltage:
If you get Windows Protection Errors or VXD errors on loading or while running Windows,
try upping your core voltage by another notch.
AGP/CLK:
Set this to 2/3 if you are having problems with your AGP card at higher bus speeds.
DRAM Data Integrity Mode:
Setting this to non-ECC can speed up systems with ECC cache slightly. When used with high
bus speeds and EEC RAM this can increase SDRAM stability.
CPU L2 Cache ECC Checking:
Disable this for a speed boost on systems with ECC L2 cache.
Disk PIO mode:
Set to PIO4 from Auto to enable some sensitive drives to function at the expense of drive
performance.
BIOS Quick
FAQ's
1)
Why is my computer beeping at me at boot up?
Many BIOS
implementations contain an array of warning beeps to alert the
user to problems. Note however, that the Award BIOS does not have
any documented beep codes past one warning (beep-beep-beeeeeeep)
which alerts to a failure to initialise the graphics card. Award
say that any other beep may indicate a RAM problem.
ta
thing to realise is that this setting does not alter your PCI
bus speed!
2) What does Spread Spectrum Modulation
in the BIOS do?
Computers
emit electrical noise, which can be commonly heard as radio interference.
This setting modulates or varies the bus speed around the setting
selected in the BIOS, ensuring that the computer does not emit
radio interference at a continuous frequency.
This setting
can hurt your performance slightly!
3) What is AGP Aperture BIOS setting
for? Is 64 megs a good setting?
AGP cards
work by dynamically allocating system memory to the video card.
The GART transfers graphics data from system memory, to video
memory. As far as the AGP card is concerned, the system memory
allocated is contiguous (e.g. starting at 0K megs going up to
64k megs in the case of a 64 meg aperture size). In actual fact
the system memory can be fragmented, but the GART maps it as one
contiguous block.
64 megabytes
is the default setting but you will not "free up" 32
megabytes of memory by setting the Aperture size to 32. The Aperture
can be thought of as a "virtual" memory block, so it
is not physically taking anything away from your system memory.
4) What does SDRAM Precharge do?
Precharge
is the amount of time in nanoseconss (ns). that the RAS and CAS
lines must be inactive before a fresh memory access can talk place.
If precharge
is enabled the precharge will be performed immediately after a
write access. This setting can therefore increase performance
on some SDRAM very slightly, especially when accessing RAM in
bursts.
5) What is Passive Release for?
Passive release
is a setting which controls how the PCI bus is accessed.
Passive release
is designed to reduce CPU utilisation by allowing bus master devices
to access the system RAM interleaved with CPU accesses. This setting
can reduce CPU utilisation when playing MPEG's or other streamed
multimedia data.
6) What is Delayed Transaction for?
Delay Transaction is a function of Intels' PIIX4 chipset. Essentially this setting alters the PCI and ISA timings slightly, and can help solve some problems with certain legacy ISA cards.
Copyright
1998/9 Andy Drake
BXBoards
http://bxboards.com
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