FSB speed

  • Thread starter Thread starter max
  • Start date Start date
M

max

Am I missing something here;

MSI 845 Pro MB
P4 1.7 GHz
133MHz SDRAM

The FSB speed is set to 100 and multiplied by 17 to give the cpu speed, ok
so far, but shouldn't the FSB be set to the same as the memory speed to
obtain the best memory bandwidth/throughput..?? As the FSB is the
connection between the CPU and memory...

This is bugging me as I understand the theory (well I hope so).... But why
is the FSB set to 100MHz..??

Or have I missed the point completely

Thx for any replies
 
Am I missing something here;

MSI 845 Pro MB
P4 1.7 GHz
133MHz SDRAM

The FSB speed is set to 100 and multiplied by 17 to give the cpu speed, ok
so far, but shouldn't the FSB be set to the same as the memory speed to
obtain the best memory bandwidth/throughput..?? As the FSB is the
connection between the CPU and memory...

This is bugging me as I understand the theory (well I hope so).... But why
is the FSB set to 100MHz..??

Or have I missed the point completely

Thx for any replies
Click to expand...

That's true with Athlon boards because both the memory and FSB are
DDR, but the P4 has quad-rate FSB, so the buffer removed from use with
the synchronous Athlon board setting, is still in use regardless. On
a P4 you want the memory bus as high as it can stabily go, which in
your situation means 133MHz theoretically safe or o'c past that.

I would expect that even if your memory clock is at +33 to the CPU FSB
clock, @ 133MHz, that when raising the FSB clock to 110, making memory
clock 143, the memory "usually" wouldn't prevent the board from at
least POSTing, it generally takes more agressive overclocking of
memory to prevent POST unless the memory timings are set quite
aggressively.

More likely your CPU needs a voltage increase if it's going to be
stable at raise FSB speed, but that's a bad CPU to o'c, since it might
not be stable at 133MHz FSB without huge voltage increase (if at all),
and starting with 100MHz FSB you're not going to see that much of a
performance increase. Might be best to just be happy with it as-is
and think about a future upgrade.


Dave
 
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