Does larger RAM mean higher CPU performance?

Question

While doing a School exam paper I saw the question:

State two characteristics, other than size of cache memory, that can improve performance of CPUs.

I answered:

1. Number of cores - Correct ✓
2. Size of Random access memory - Incorrect ×

I understand that there is not a direct correlation between size of RAM and CPU performance.

This site says that more RAM means "Smoother Multitasking". Suggesting that it does improve performance.

However http://lifehacker.com/5415355/do-you-really-need-more-than-4gb-of-ram says that it will not improve the performance of 'single' tasks.

www.youtube.com/watch?v=OqRyqdHhsRs shows that a small amount of RAM really effect loading times and performance.

So does a larger RAM make for better overall performance?

Answer 1

More RAM generally means better overall performance. It does not mean better CPU performance.

If you wish you can simplify it by comparing it to a car. Having a larger trunk (without making the car heavier or changing anything else) means you can transport more goods in the same time. However it does not increase horsepower of the engine. (The CPU in this case would be the engine.).

What more memory does help with is:

1. No or less need to use (slow) paging.
2. More memory to use as disk cache (meaning the CPU is less likely to wait for slow disk IO).

What it does not help with is if you already have more available memory than you need.

Answer 2

More RAM helps in many cases such as running programs which are memory intensive, and also improves OS speed overall, but it does not mean it improves CPU performance.

The CPU only processes instructions sent to it, while RAM stores temporary data which is only needed during an application's run-time, such as an integer called 'n', for example, which means that CPU performance will virtually stay the same with more RAM.