Трябва ли да купите допълнителна RAM за стар компютър?

I have an older computer (from 2008), an HP Compaq 6510B, that does not have amazing specs, but is not too bad either. I have Ubuntu 14.04 LTS 64-bit set up on it. While it can be very good for some tasks, it can easily get laggy and slow, especially when running Google Chrome, Chromium, or other RAM-heavy programs.

I installed the Lubuntu desktop and used that as my session once, but saw no noticeable improvement (so my guess is that it is not related to Ubuntu’s eye-candy).

The computer only has 2 GB of RAM (two slots with 1 GB each), but I can replace those with two 2 GB sticks and upgrade it to 4 GB. I am wondering whether I should or not.

I know that sometimes a computer is no better than the weakest part, so maybe adding more RAM will not help at all. I also do not want to reach the point where I replace so many parts that I could have just as easily bought a new computer. How can I figure out if upgrading the RAM is worth it or not?

Adding more RAM to a system is one of the easiest ways to boost your system’s performance. When a system runs low on RAM for applications, it is forced to use the hard-drive for swap space. Given that a hard-drive is orders of magnitude slower than RAM, this can be a bottleneck for your system’s performance.

Before just running out to buy more RAM (especially since DDR2, which your system takes, is going to be more expensive than the current-model DDR3), you may want to run some analyses to see how much of your RAM is being utilized when you notice the lagging, as well as the amount of swap space utilization. If you find that the RAM is not fully used and/or the swap space is not being hit hard, then it is probably just a deficiency in your processor or other parts of your system.

Addendum from @George:

You can do this by opening a terminal window, and then typing free. The output will look like this:

End of Addendum

Another possibility to look into is replacing your hard-drive with an SSD. This will improve system performance by reducing read times (especially for loading programs) and will also improve swap performance (though not as well as more RAM will).