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CPU Cache

The CPU is more than just the processor — it also contains cache memory. This is a very small amount of memory that provides the fastest memory available to the CPU. Most CPUs have a level 1 and level 2 cache, but some even have a level 3 cache. Because the processor operates so quickly, we want the most-frequently-used information to end up in the cache to speed up the processing. When the processor needs information, it first checks the location “closest” to it (level 1 cache). If the information is not in the level 1 cache, the CPU then checks level 2, then level 3. If the information is not in either of those cache levels, the CPU then reaches out to the system RAM (the next fastest location), and if the information is not there, the CPU then looks to the hard disk drive (the slowest location). By continually trying to find the information closer and more quickly, the processor operations are sped up.

System performance is improved through the use of cache memory, by enabling the processor to use recent memory locations (cache) rather than retrieving information from main memory.

The bottom line when it comes to cache and performance — larger cache results in faster CPU performance.

Earlier, we mentioned the various types of expansion cards; now we are going to focus on video/graphics cards. Video cards come in many varieties, and are sold under numerous different naming conventions, like graphics cards, graphics accelerator cards, or graphics adapters. These cards are add-on cards that create the images you see on the display/monitor. They can come in a variety of expansion card types to fit into the various expansion slots, such as PCI express (PCIe) that is currently dominant, advanced graphics port (AGP), or the older PCI slots. While many low-end desktops come with an integrated graphics chip in the CPU instead of using a dedicated card, this is not suitable for 3D games or CAD/CAM (computer-aided manufacturing) workstations. Therefore, many users will opt to use an add-on graphics card, like the one displayed below, to improve their gaming performance.

Video card. Photo used under CC-BY-NC-ND license from Nelson Wu.

Video cards contain a very strong processor called a graphics processing unit (GPU) which performs the extensive mathematical calculations involved in rendering the 3D images that most games require. This extensive processing creates a lot of heat. So, properly cooling the graphics card is essential. Many cards, especially lower-powered ones, will use a passive heat sink for quiet operations, or will rely on the case fans to remove the heat. Most modern graphics cards actually use dedicated cooling fans and heat shrouds for better cooling, but they are much noisier due to the fans involved, and often required external power. The image above shows an example of a video card with an enclosed shroud and active cooling fan to draw the heat away from the card.

Installing video cards is very similar to installing any other expansion card. First, you must go into the BIOS and ensure the slot is enabled (AGP or PCIe x16). This may require some configuration changes, such as the AGP speed, turning off the onboard graphics chip, or adjusting the graphics memory size. Next, you will want to power off the machine, remove the power, use proper ESD precautions, and install the new expansion cards into the proper slot. Next, cable the monitor to the card, plug the computer back into the outlet, and turn on the computer. Once the computer boots into the operating system, you will need to install the device drivers to ensure the operating system can provide the best graphics available from your new card.

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