How Much RAM Do You Really Need?
Jon Kullberg, Patrick Schmid, Dec 2005

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The Need To Invest In 2 GB Of RAM Is Not Marketing Hype



How much RAM does your PC have? If you run Windows XP, it is probably in the range of 512 MB to 1 GB. Older Windows versions will do the job with less than that, but as soon as you execute demanding applications or more than one application at a time, anything below 512 MB will likely translate into performance bottlenecks.

Of course, the more RAM you have, the better off you are - but how much memory do you really need?

Multiple software threads that run all at once every time you boot up your PC continue to proliferate. Multitasking software includes what we really need, such as anti-virus tools or firewall software, or useful programs to which we have all grown accustomed that permanently run in the background until they need our direct attention. Most users, for example, have their email client and browser permanently available. Instant messengers such as AIM, ICQ MSN or YIM increasingly pop up on a growing number of desktops, while a media player plays music while you work. And all of these consume some memory, leaving fewer resources available for applications that you want to launch.

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Memory Matters

Many believe that one gigabyte of RAM is enough for virtually any non-professional application scenario. Unfortunately, that is not the case. Have you ever launched a recent gaming title with lots of resource-hungry applications already launched? Everything might seem fine as Windows relocates the applications' memory data to the swap file on your hard drive. However, as soon as you hit a Windows key accidentally, the OS will hectically try to exchange the gaming data in the main memory by the application data that was swapped before

Cached Vs. Non-Cached Benchmarking

When using Doom 3 for benchmarking, you initially run the demo a few times and ignore the first results since they are lower. The reason for the lower result is that the game reads texture and map data from the hard drive to system memory, and hard drive access is a FPS killer.

If you don't shut down the game after the first run, the demo will be cached in the system memory, thus avoiding the hard drive access penalty the next time you run it. If you're testing a CPU or a graphics card, you obviously won't take the first run into account since you don't want the hard drive access to affect your results.

However, the testing methodology used to determine the RAM's impact on performance is different. In this case, gauging performance involves the benchmark results generated the first time you run the demo.

Think about it: Did you ever load a saved game, complete the level, load the same saved game again and play the level one more time just to avoid low performance caused by hard drive access? The resulting performance gain is why we included the first runs in the graph - and don't worry, the first run results were very consistent.

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