Does FSB speed matter?

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Here is two CPUs:

Core 2 Duo E4700 (2.6GHz,  800 FSB,   L2: 2MB)
Core 2 Duo E6700 (2.66GHz,1066 FSB, L2: 4MB)

The biggest differences about the processors: the FSB. Let's fancy
another two processors:

A: Core 2 Duo (2.6GHz,  800 FSB,   L2: 2MB)
B: Core 2 Duo (2.6GHz,  1066 FSB,  L2: 2MB)

Can I feel different performance if I don't change anithing in the
computer except the CPUs (A -> B)? Of course, the motherboard support
both type of CPU.

Does FSB speed matter?

Thank You!

Re: Does FSB speed matter?

FSB speed does matter, but you will need faster memory to take advantage of the
higher bus speed. L2 cache size also matters. There could also be other
differences between processor cores, although I believe all Core 2 chips operate
essentially the same. wrote:
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                   Mike Walsh

Re: Does FSB speed matter? wrote:

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question is do you need the extra speed and are you willing to pay extra to
upgrade the ram

Re: Does FSB speed matter?

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Thanks Mike!

The RAM in the machine is fast as possible but the CPU is not. I want
to replace the Pentium D but I didn't know, witch one is the better

I've got 4 GB RAM but the CPU is "not the best".

Re: Does FSB speed matter?

On Mon, 21 Apr 2008 01:59:34 -0700 (PDT),

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False, the 2nd has double the L2 cache which is about 5-15%
performance difference on average, depending on the
application.  In other words, the 2nd CPU is faster than the
first, and priced accordingly.  You are making a simple
choice difficult, the choice being whether you are willing
to pay more for more performance (same choice as always,
with every year and every family of CPU).

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No you won't feel, or perceive the difference, but the same
is true for each minor difference in performance in memory
or video, HDD, etc.  In other words if you add up several
parts in a PC, each of which is barely enough of a
performance increase to notice, the end sum of all
improvements IS enough to notice.

Pick the fastest FSB and largest L2 cache the budget will
reasonably allow, unless you plan on overclocking.  If you
plan on overclocking, getting a processor with lower default
FSB (if all else were equal) would allow raising FSB more
for higher O'C before you hit a FSB limit.

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Of course it does, why else do you think they would be using
faster FSB than previously?

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As fast as possible is not a specific.  You want a specific
answer to a specific question you have not asked, and you
have not provided the specifics of the other parts nor the
tasks you run.

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You are not being specific about what Pentium D you have,
nor what your motherboard's max FSB is which may be lower
than 1066 if the motherboard is very old.

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Neither of the CPUs listed is "the best" either, so
ultimately you have not supplied the relevant information
for us to help you make any meaningful choice.

It would be more helpful to you if you listed the following:

-  Current motherboard make and model

-  Number of memory  modules, total capacity (listed again
in concise form), spec'd speed

-  Desired CPU price, budget range

-  Applications in which you need the performance boost

Some old Pentium D boards don't even use DDR2 memory, having
the fastest DDR(1) memory like PC3200, makes it fairly
irrelevant if your board has the fastest memory it can
support as it would still bottleneck the CPU.  Also we don't
know but assume you do, whether your board supports the
above listed processors.

A generic answer is as written above, pick larger L2 cache
and faster FSB for more performance if the mobo supports
that FSB, unless you are overclocking in which case you want
lower FSB than the max your board supports so you have some
room to increase FSB (since multiplier cannot be raised).

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