FSB Question

[Steven Liburd]

I have an Athlon XP 1800+ system that I just upgraded to 512Meg with a
single DDR400 module. My question is would this CPU be enhanced by
running the FSB at 200MHz? I know the CPU specs say that the FSB should
be run at 133MHz, but, if I run it faster because that memory can handle
it (and adjust the clock multiplier so that the CPU isn't being
overclocked), should that result in a performance boost? Or, is there
nothing to be gained by this? TIA

==steven

 

[John Doe]

I have an Athlon XP 1800+ system that I just upgraded to 512Meg
with a single DDR400 module. My question is would this CPU be
enhanced by running the FSB at 200MHz? I know the CPU specs say
that the FSB should be run at 133MHz, but, if I run it faster
because that memory can handle it (and adjust the clock
multiplier so that the CPU isn't being overclocked), should that
result in a performance boost? Or, is there nothing to be gained
by this? TIA

Apparently, running the CPU and memory at the same FSB speed is
best. I guess it's sort of like when you combine different speeds
of memory, they perform at the lowest speed. You can try and test
it like I did. There was a very slight performance degradation
when I tried to run the memory faster than the CPU.

You can significantly improve memory performance by buying a 200
MHz FSB CPU and then running them both at 200 MHz, like I did.
But I guess that depends on what system properties your applications
need.

 

[David Maynard]

I have an Athlon XP 1800+ system that I just upgraded to 512Meg with a
single DDR400 module. My question is would this CPU be enhanced by
running the FSB at 200MHz? I know the CPU specs say that the FSB should
be run at 133MHz, but, if I run it faster because that memory can handle
it (and adjust the clock multiplier so that the CPU isn't being
overclocked), should that result in a performance boost? Or, is there
nothing to be gained by this? TIA

==steven

It would be a bit faster but it's unlikely your 1800+ is unlocked, meaning
it's multiplier will be what it is regardless of what you 'set'.

 

[John Doe]

Steven Liburd wrote:

It would be a bit faster but it's unlikely your 1800+ is
unlocked, meaning it's multiplier will be what it is regardless
of what you 'set'.

Really?

My Athlon XP 2400+ (133 MHz FSB) allowed for changing the
multiplier. If that were not the case, setting the FSB at 200 MHz
would have failed completely instead of just causing a slight
degradation in performance.

 

[David Maynard]

Really?

My Athlon XP 2400+ (133 MHz FSB) allowed for changing the
multiplier. If that were not the case, setting the FSB at 200 MHz
would have failed completely instead of just causing a slight
degradation in performance.

And just what, precisely, makes you think that having an unlocked
processor, of not even the same speed, means that they all are?

His may or may not be unlocked but, IMO, it's unlikely, the exact word I
used, and that you have 'one' doesn't prove otherwise.

 

[John Doe]

And just what, precisely, makes you think that having an
unlocked processor, of not even the same speed, means that they
all are? His may or may not be unlocked but, IMO, it's unlikely,
the exact word I used, and that you have 'one' doesn't prove
otherwise.

What suggests that they are locked? Usually we hear about such
things.

 

[Jan Alter]

My Athlon XP 2400+ (133 MHz FSB) allowed for changing the

multiplier. If that were not the case, setting the FSB at 200 MHz
would have failed completely instead of just causing a slight
degradation in performance.

When I put together an Athlon XP 2500 (166 mhz FSB) a couple of years ago I
paired it with PC 3200 RAM (200 mhz). I changed the FSB to 200 mhz for the
cpu. Everything seemed to run just fine except for one program. When I
attempted to render video the operation would freeze anywhere from 10
minutes to 2 hours into the operation. Once and awhile the movie would
complete and I thought it a bug in the program that was causing the problem.
I eventually decided to do the video rendering on an Intel machine, and I
never had a problem with the final product. A few months ago I decided to
rechange the FSB on the Athlon back to 166 mhz. And what do you know the
video rendering went smoothly without freezing. I've done at least half a
dozen movies without any problems since then with the Athlon.
If changing from factory default specs one should be mindful, expecially
of high cpu intensive needs, that the change may only make itself apparent
at that time.

 

[David Maynard]

What suggests that they are locked?

The fact that AMD locked them.

There was a brief period during the Thoroughbred core that AMD didn't lock
them and then they went back to locking them again.

Usually we hear about such
things.

Apparently you don't.

 

[Steven Liburd]

There was a brief period during the Thoroughbred core that AMD didn't

lock them and then they went back to locking them again.

Is there a way to tell? Do programs such as CPUZ just report what it
finds in the BIOS, or is it calculating results based on other factors?

==steven

 

[David Maynard]

Is there a way to tell?

Visual inspection to see if the little jumper traces are laser cut.

There are also web instructions for an incredibly tedious method of
reconnecting the things. Try a search for "unlock AMD Athlon XP."

I'm posting with an XP 1800+. Mine is locked.

The 1800s are also not the best overclockers. I can get, whooptedoo, 2000+
out of mine.

Do programs such as CPUZ just report what it
finds in the BIOS, or is it calculating results based on other factors?

I'm not sure about CPUZ but I'd imagine it checks the actual operation.
Some BIOSes, however, will report what you 'tell it' regardless of whether
it actually does anything so it might say Woopie-Mhz when it isn't.