Corsair AN806 user manual

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AN806: Memory Upgrade Resource Guide
Mike Clements, Corsair Memory Inc.
Introduction
Here at Corsair we are always looking forward. One current trend we have noticed is the
growing number of people upgrading their desktop PC memory. Due to the progression of
current memory offerings and current motherboard offerings, there are a growing number of
factors to consider before making your upgrade. These factors can greatly impact the
effectiveness of the memory upgrade.
The most critica

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A user that already has a pair of modules and adds a second pair should take care to purchase a kit as similar as possible to the original to have the greatest chance of successful integration. This ensures a high likelihood of success when running a system with all four DIMM sockets populated. The number of modules used can also have an effect on users attempting to utilize EPP or XMP performance profiles. Some BIOS implementations will not allow the selection of these options when runnin

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bytes, which equates to 4GB. However, part of this 4GB „address space‟ must be reserved for devices that require MMIO (Memory-Mapped Input Output). As an example, one such device is the graphics card, which requires an amount of address space equal to its frame buffer size (the amount of memory installed on the card) to be „reserved‟ for such data exchanges. This reserved address space is therefore not available to Windows as accessible memory. Memory usage in 64-bit operating systems W

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for the video memory. As another example, if we were to add a sound card with 64mb of onboard memory, the addressable amount of system memory would drop to approximately 3.186MB. In the configuration above, I have approximately 768MB of system memory that cannot be addressed by the OS. Therefore, it cannot be utilized. However, the positive is that I do have 3.25GB of usable system memory. This is a substantial increase over 2GB so a person should not consider this address space limitation

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selection is critical also. Corsair provides multiple resources in addition to our applications notes to assist our customers with memory purchases. Resource Listing We recommend the following resources for more useful information on this topic: RAM Guy Forums These forums are populated day and night with memory experts from around the world. There are countless threads describing upgrading issues and how to solve them. The forum can be found at http://www.asktheramguy.com. The Corsair