GA-7VRXP: rev. 1.0 or 2.0? And FSB 333?

Mike wrote:
|| I felt it worthwhile pointing out that the CPU FSB clock rate and
|| the memory bus clock rate are different things, as some newsgroup
|| posters seem to confuse the two. Fortunately, on the GA-7VRXP they
|| can be set independently.
|
| OK. So to conclude we have a FSB or system bus speed that runs on
| either 100 or 133 MHz which can be selected at the board with a
| switch. We have a memory bus that runs on 100, 133, or 166 MHz which
| can be selected through the BIOS. And we have a CPU clock speed that
| can be adjusted through the BIOS from 133 to at least 166 MHz. Am I
| right?
|
| And a FSB of 166 is simply not possible without alteration of the
| board, right?

Correct on all points, except that you are making a distinction between the
processor clock and the FSB clock - they are the same thing ! That is why I
describe it as the 'CPU FSB' clock. And yes, it can be set to run at either
100 MHz or 133 MHz on a GA-7VRXP.
Looking at it from a different angle:
The motherboard 'northbridge' chip includes a memory management function and
thus sits logically between the CPU and the memory. The northbridge has two
sides: the side which communicates with the CPU is known as the 'front'
side, so the data bus between CPU and northbridge is known as the 'front
side bus' - ie: FSB. There is a limit to the speed any particular CPU can
have its FSB clocked at, and there is also a limit to what speed a
northbridge chip can have the FSB clocked at. If you attempt to run the FSB
faster than these limits then you are 'overclocking' it which might cause
problems. On the GA-7VRXP you can only set the FSB clock to 100 or 133 MHz.
Bear in mind that due to a technology known as double-data-rate (DDR) data
will be strobed through the bus on both the leading and trailing edges of
the FSB clock signal, so the maximum data rate will be 266 MHz (2 x 133
MHz).
There is also a limit to what speed any particular type of memory can be run
at. The 'memory side' of the northbridge chip is connected to the memory on
the memory bus (the DMA controller also uses this bus, but that is another
matter) and data is strobed on the memory bus by the memory clock. When
setting the memory clock speed the limitations of the memory and the
northbridge chip have to be taken into account. The VIA KT333 northbridge
chip on the GA-7VRXP can manage a top memory data rate of 333 MHz. DDR is
used on this bus, so the memory bus clock speed is set at half the DDR
rate - 166 MHz maximum, or 133 MHz or 100 MHz if you have slower memory -
via a BIOS setting.
A particular advantage of modern northbridge chips like the VIA KT333 is
that they can run their front side bus and memory bus at different speeds.
That is why you have two settings.
The CPU speed is the frequency the CPU is clocked at. This is dependent on
the capabilities of the CPU used - for example, an XP2400 CPU is specified
as working at 2.0 GHz. Run it faster than this and you are 'overclocking'
it. It might work, but AMD don't guarantee that it will. The CPU speed is
derrived as a multiple of the FSB clock speed, and can be varied on the
GA-7VRXP by means of a bank of switches. To be honest, unless you actually
want to over-clock the processor - or need to under-clock it for some
reason, it is best to leave the 'multiplier' switches on the default 'auto'
setting.
Kevin.