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CPU 2mb cache VS 4mb

Posted: Sun Apr 22, 2007 4:32 pm
by potato
Hey,

i was wondering if its a big difference if i choose a dual core with 2MB cache instead of 4MB?
Is it really worth the extra cash?
Will i see any difference?

greets,
tom

Posted: Mon Apr 23, 2007 8:03 am
by feyd
There's can be a fairly significant difference in perceived speed of a machine with those cache levels.

Posted: Mon Apr 23, 2007 10:27 am
by pickle
Depends how much the extra cost is ;). Obviously, you'll be doubling the amount of information that can be stored directly on the chip, which will really help for processes that access consecutively stored data, or re-use certain parts of data (which is most programs). It's probably worth the upgrade.

Posted: Mon Apr 23, 2007 7:16 pm
by the_last_tamurai
I've the 4MB ....

really it worths 8)

Posted: Mon Apr 23, 2007 7:27 pm
by JAB Creations
It depends, are you doing anything processor intensive?

My second AMD system was a single core socket 754 at 2.00 GHz with 1MB cache which chewed through a 120MB access log in under 20 seconds.

My system to follow was a single core 2.2GHz processor with 512KB that did the same task in roughly one minute. That's an extra 200 megahertz advantage in addition to dual channel memory and it took almost four times longer to complete the same process!

This task I tested this with was processing 120 megabyte access log through AWStats locally on my computer using Apache. Depending on your task it may or may not effectively change your perception between two processors with different amounts of cache for the same socket and processor speed.

So if you actively know you're locally performing processor intensive tasks I'd recommend the extra cache.

Posted: Tue Apr 24, 2007 9:19 pm
by toasty2
The difference is generally insignificant. At least thats what benchmarks show... Of course, its still better to have more. I have 2MB cache on my processor. (AMD Opteron 1212, which I also have overclocked :D ).

Posted: Tue Apr 24, 2007 9:27 pm
by JAB Creations
I'm not following processors as closely as I did during the 939 era though there is one thing to be aware of: cache per core. Just because you have 2MB cache total does not mean it will use all 2MB. If a process is using up one of your cores might only use the cache on that core. I've read someplace that AMD/Intel may be trying to figure out how to share all the cache between all cores but it's been at least a couple months since I've read about anything in regards to cache. Still shared core cache sweetens the deal even more, again if you're actually using it.