How does having a high cache affect your PC performance?

Question

I know about processing power, graphics and sound cards, and memory (RAM), but how does having a big cache affect the performance of your PC?

Bonus question: When is it worth it to go dual-core? Do you need high RAM or cache size to get the most out of it?

Answer 1

Yes, it definitely does. In my experience, the bigger (size), and faster the cache is (speed), the quicker your computer starts up to begin with and loads windows, it loads your programs faster, and documents as well. RAM is over rated, you are better off with a better graphics card because your display has to keep up with the rest of the computer (CPU, RAM, Cache, etc.).

Dual-Core, or any other Multi-Core is over rated as well (those manufacturers just found a good way to market old chips by sticking them together). I got a laptop this year that had a 1.67 GHz Dual-Core chips, and I wish I would have gotten a 2.6 GHz or a 3.0 GHz Single-Core chip instead. The only time you would benefit from a dual core, is if you are multi-tasking, that is running multiple programs, and have multiple screens, or monitors. Instead of a Dual-Core, I would go for one with HT Technology (Hyper Threading) which does something similar to multi-core chips, but once again it does seem to come down to your Cache size and speed, especially when you see that Cache indicator light go on and stay on when you are trying to load or start something. And just because you have Dual-Core, and Dual-Cache, it does not mean that you are actually benefiting from both of them, because it depends on what you are doing. Just because you have two chips, it does not mean you will process the information twice as fast, it means that you wil be able to process twice as much information at the same time, not faster, that's all. Primarily you will be using a single-core and single-cache. I don't know what's out on the market, but sometimes it's hard to keep track of this all important Cache size, because that's not what they are marketing.

That's your basic answer, short of going scientific. I win!

Answer 2

The answer to both questions is the same: It depends what the computer is doing.

In general, larger caches increase the "hit ratio", the number of references that can be satisfied in the cache without going to memory. Since the cache is much, much faster than a memory reference, the higher the hit ratio, the better performance you get. However, the applications you run are the major determinants of cache behavior. Applications with large virtual address spaces and highly nonlocal reference patterns will have low cache hit rates, no matter how large the cache.

Likewise, in an environment that is not CPU bound, adding a second CPU may not appreciably improve performance. However, the nature of most popular operating systems almost guarantees some use of the 2nd processor.

In theory, neither large amounts of RAM nor large cache sizes are necessary to make use of dual processors. But again, depending on what you are running they may be helpful.

I believe that dual-core processors each have their own cache, but I'd have to look that up.

If you are going to run 2 copies of something that is a pig for memory, then yes, your dual core configuration would benefit from more memory.