P4B Question

I have a plain P4B motherboard. Does someone know the highest speed P-4
processor it will take.

Thanks

In article , "Crhoff"
wrote:

I have a plain P4B motherboard. Does someone know the highest speed P-4
processor it will take.

Thanks

You can look it up here. It says P4 2.6GHz FSB400.

http://www.asus.com.tw/support/cpusu...pusupport.aspx

If the board is overclockable on the FSB, you might also
consider a FSB533 processor, but it could not be a Prescott
or a Celeron D (90nm). The board is likely to work with
Northwood processors (0.13u). I cannot find any good examples
in Google, of someone doing this, and the only reason I
suggest it, is to give your processor as much bandwidth
as possible from the memory to the core. Above 1.8GHz, the
processor would be pretty starved if it was using PC100
memory, and some PC133 memory and a FSB533 bus would be the
best conditions you could arrange for it. PC133 and FSB400
would be second best, and PC100 plus FSB400 the lowest of
the lot. (If running the bus at FSB533, the CPU clock is
133MHz, and the CPU/Memory divider in the BIOS should be
set to 1:1, which is the lowest it will go. Thus, you need
PC133 memory.)

To see how the FSB can be pushed, start he

http://www.cpudatabase.com/CPUdb

Select P4 1.8A from the pulldown menu in the Intel section.
There is an entry there, where a P4B motherboard is used
to run a SL63X 1.8GHz FSB400 processor at 2.7GHz. That
means the FSB is running at (2.7/1.8)*400 = FSB600 and
implies to me that buying a FSB533 processor might work.
You may have to set the clock manually, if the board
doesn't do the right thing when the FSB533 processor is
plugged in.

You can look up SLxxx codes on processorfinder.intel.com
to get details on processor models.

In terms of the fastest processor you can buy, there is
a P4 2.8GHz FSB400 processor for sale at Powerleap.com .
They stockpiled some of them, for sale to owners of
FSB400 boards. If you go this route, you are treating
the busses conservatively, and will get the full 2.8GHz
performance on CPU bound calculations. But if you were
running Photoshop or other memory intensive program
under those conditions, or perhaps using PC100 memory,
don't expect to see that much of a difference from
your current processor, as the processor will spend
a lot of time "stalled" waiting for memory access to
complete.

In terms of why the Asus list may stop at a certain
processor speed, the Vcore circuit will have some
limit as to how much current it can source. You can
guess at this limit, by looking up the fastest processor
listed in the Asus list, and seeing the characteristics
on the processorfinder site.

This is a Powerleap 2.8GHz processor. 68.4W/~1.5V=45.6 amps
http://processorfinder.intel.com/scr...ALL&CorSpd=ALL

This is Asus 2.6GHz processor. 62.6W/1.53V=40.9 amps
http://processorfinder.intel.com/scr...ALL&CorSpd=ALL

By working out the current in amps for the various processors
that are rated to work in the board, you'll get an idea
of how far over or under spec your new processor would be.
Unfortunately Asus does not list the max current figure used
to design the Vcore circuit, so this is the only way I know
of, to guess at the limit.

If you don't want to do any research at all, stick with
the 2.6GHz FSB400 processor, as listed on the Asus
cpusupport page. Your choice.

In terms of the "dip switch" settings offered in the manual,
be careful not to select a setting that runs the PCI above
37.5MHz. For example, the 120/80/40 setting is not a good one,
and could cause IDE disk corruption. Whether set with the dip
switches or not, that setting would be a problem. Also, the
multiplier section of the dip switch won't do anything,
because the processors are multiplier locked. Only if somehow
you got an Intel "Engineering Sample" ES processor, would you
need to set a particular multiplier, so you can ignore the
multiplier and focus on the processor clock choices.

Good luck and good hunting,
Paul

Thanks a bunch, Your info helped a lot


"Paul" wrote in message
...
In article , "Crhoff"
wrote:

I have a plain P4B motherboard. Does someone know the highest speed P-4
processor it will take.

Thanks

You can look it up here. It says P4 2.6GHz FSB400.

http://www.asus.com.tw/support/cpusu...pusupport.aspx

If the board is overclockable on the FSB, you might also
consider a FSB533 processor, but it could not be a Prescott
or a Celeron D (90nm). The board is likely to work with
Northwood processors (0.13u). I cannot find any good examples
in Google, of someone doing this, and the only reason I
suggest it, is to give your processor as much bandwidth
as possible from the memory to the core. Above 1.8GHz, the
processor would be pretty starved if it was using PC100
memory, and some PC133 memory and a FSB533 bus would be the
best conditions you could arrange for it. PC133 and FSB400
would be second best, and PC100 plus FSB400 the lowest of
the lot. (If running the bus at FSB533, the CPU clock is
133MHz, and the CPU/Memory divider in the BIOS should be
set to 1:1, which is the lowest it will go. Thus, you need
PC133 memory.)

To see how the FSB can be pushed, start he

http://www.cpudatabase.com/CPUdb

Select P4 1.8A from the pulldown menu in the Intel section.
There is an entry there, where a P4B motherboard is used
to run a SL63X 1.8GHz FSB400 processor at 2.7GHz. That
means the FSB is running at (2.7/1.8)*400 = FSB600 and
implies to me that buying a FSB533 processor might work.
You may have to set the clock manually, if the board
doesn't do the right thing when the FSB533 processor is
plugged in.

You can look up SLxxx codes on processorfinder.intel.com
to get details on processor models.

In terms of the fastest processor you can buy, there is
a P4 2.8GHz FSB400 processor for sale at Powerleap.com .
They stockpiled some of them, for sale to owners of
FSB400 boards. If you go this route, you are treating
the busses conservatively, and will get the full 2.8GHz
performance on CPU bound calculations. But if you were
running Photoshop or other memory intensive program
under those conditions, or perhaps using PC100 memory,
don't expect to see that much of a difference from
your current processor, as the processor will spend
a lot of time "stalled" waiting for memory access to
complete.

In terms of why the Asus list may stop at a certain
processor speed, the Vcore circuit will have some
limit as to how much current it can source. You can
guess at this limit, by looking up the fastest processor
listed in the Asus list, and seeing the characteristics
on the processorfinder site.

This is a Powerleap 2.8GHz processor. 68.4W/~1.5V=45.6 amps

http://processorfinder.intel.com/scr...ALL&CorSpd=ALL

This is Asus 2.6GHz processor. 62.6W/1.53V=40.9 amps

http://processorfinder.intel.com/scr...ALL&CorSpd=ALL

By working out the current in amps for the various processors
that are rated to work in the board, you'll get an idea
of how far over or under spec your new processor would be.
Unfortunately Asus does not list the max current figure used
to design the Vcore circuit, so this is the only way I know
of, to guess at the limit.

If you don't want to do any research at all, stick with
the 2.6GHz FSB400 processor, as listed on the Asus
cpusupport page. Your choice.

In terms of the "dip switch" settings offered in the manual,
be careful not to select a setting that runs the PCI above
37.5MHz. For example, the 120/80/40 setting is not a good one,
and could cause IDE disk corruption. Whether set with the dip
switches or not, that setting would be a problem. Also, the
multiplier section of the dip switch won't do anything,
because the processors are multiplier locked. Only if somehow
you got an Intel "Engineering Sample" ES processor, would you
need to set a particular multiplier, so you can ignore the
multiplier and focus on the processor clock choices.

Good luck and good hunting,
Paul