relationship between speed and cache - Intel CPU

The size of the cache in intel Core 2 Duo has an impact on their performance.

What is the relationship between speed and the amount of cache for the same familly of CPU? is the following correct?

1/
Pentium Dual Core 2.00GHz + 1MB + FSB 166 same as
Core 2 Duo 1.83Ghz + 2MB + FSB 166 same as
Core 2 Duo 1.66Ghz + 3MB + FSB 166 same as
Core 2 Duo 1.50Ghz + 4MB + FSB 166 same as
Core 2 Duo 1.33Ghz + 6MB + FSB 166

2/ What is the boost in performance gained from a higher FSB?
Core 2 Duo 2Ghz + 2MB + 200FSB is 10% faster than
Core 2 Duo 2Ghz + 2MB + 166FSB is 10% faster than
Core 2 Duo 2Ghz + 2MB + 133FSB

(I know the above is not correct so feel free to correct me)

 

There is no mathematical equation that gives you the performance difference among different caches and/or FSBs. It all depends on the applications.

So let's say an app X deals with 0.8MB of data. The data set will fit to a 1MB cache and no matter how large your cache is (eg. 2MB, 4MB, 6MB...), you will see no performance increase. The only factor that makes a difference in performance will be the clock frequency...


--

 

Ok

So what type of applications that would use 6MB of cache? (CAD, DTP...)

 

L2 cache is a lot like system memory - it does nothing unless it's needed.
So as long as the main executable you are running fits in the L2 cache, it will perform a lot better.
For example, the Crysis executable is just under 6MB, so Crysis actually runs better on CPUs with 6MB of L2 or more than those with 4MB or less.
Any CPU intensive application will benefit from L2 cache, especially encoding, compressing/decompressing, rendering, games.

 

The reason I asked all these question is because in Sandra Sysoft, both CPU benchmarks showed a little difference between CPUs running at the same speed but with a different cache size.

It was like:
T7200 = T7300 = T8100
T7400 = T7500 = T8300 = T9300

 

Other factors play in on CPU performance than clock speed and L2 cache, such as front side bus.

 

I know, but if you see at the begenning of the thread I'm looking/comparing CPUs that have the same FSB

 

Except the CPUs you just compared, as if L2 and speed was their only difference have different cores and different FSBs