Standard DRAM Memory

[Crucial_FAQ]

We want all of our members to enjoy their experience in the Crucial forum community. Please bear in mind the following when asking for help:

1. Please do not post in all caps. This is unnecessary and makes the forums difficult to read.

2. Create new posts for your specific issue, unless a solution has been posted prior. (Use "search" function to find a solution that has already been posted. Do not change the subject headlines for other posts.)

3. Post a subject title that provides a clear indication of the problem you are experiencing. For example. posting something like "Major problem!! Look inside!" does not communicate anything about the issue you are facing.

4. Please provide the following information:

• Make and model names of computer or motherboard. If you do not know this information, click on the following link to use our system scanner.

http://www.crucial.com/systemscanner/

When the scanner has finished, copy the URL from your browser's address bar and paste it into your post, so we can find the information.

• Crucial Part Number. The one from the part, not the one from the scan result page (the two are different).

• A detailed description of issue.  Simply saying "part is not working" does not provide enough information to be able to give a detailed, helpful response.

[Crucial_FAQ]

We want all of our members to enjoy their experience in the Crucial forum community. Please bear in mind the following when asking for help:

1. Please do not post in all caps. This is unnecessary and makes the forums difficult to read.

2. Create new posts for your specific issue, unless a solution has been posted prior. (Use "search" function to find a solution that has already been posted. Do not change the subject headlines for other posts.)

3. Post a subject title that provides a clear indication of the problem you are experiencing. For example. posting something like "Major problem!! Look inside!" does not communicate anything about the issue you are facing.

4. Please provide the following information:

• Make and model names of computer or motherboard. If you do not know this information, click on the following link to use our system scanner.

http://www.crucial.com/systemscanner/

When the scanner has finished, copy the URL from your browser's address bar and paste it into your post, so we can find the information.

• Crucial Part Number. The one from the part, not the one from the scan result page (the two are different).

• A detailed description of issue.  Simply saying "part is not working" does not provide enough information to be able to give a detailed, helpful response.

[Crucial_FAQ]

Please also note that the purpose of the community is for users to help each other. Crucial Moderators keep an eye on the boards and will only jump in with assistance where required or after a certain amount of time has passed.

If you would like a quick and direct response from Crucial you can call us or use the Live Chat facility. Just click on the link below for your location, click "More contact options," and then select Customer Service to view our contact information.

US - www.crucial.com/contact
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EU - www.crucial.com/eu/contact

Note: Please do not use the "report abuse" feature to ask questions or request help.  That feature is to be used for reporting abusive or incorrect posts, not to contact Customer Service.

[Crucial_FAQ]

Please also note that the purpose of the community is for users to help each other. Crucial Moderators keep an eye on the boards and will only jump in with assistance where required or after a certain amount of time has passed.

If you would like a quick and direct response from Crucial you can call us or use the Live Chat facility. Just click on the link below for your location, click "More contact options," and then select Customer Service to view our contact information.

US - www.crucial.com/contact
UK - www.crucial.com/uk/contact
EU - www.crucial.com/eu/contact

Note: Please do not use the "report abuse" feature to ask questions or request help.  That feature is to be used for reporting abusive or incorrect posts, not to contact Customer Service.

[Crucial_FAQ]

Please also note that the purpose of the community is for users to help each other. Crucial Moderators keep an eye on the boards and will only jump in with assistance where required or after a certain amount of time has passed.

If you would like a quick and direct response from Crucial you can call us or use the Live Chat facility. Just click on the link below for your location, click "More contact options," and then select Customer Service to view our contact information.

US - www.crucial.com/contact
UK - www.crucial.com/uk/contact
EU - www.crucial.com/eu/contact

Note: Please do not use the "report abuse" feature to ask questions or request help.  That feature is to be used for reporting abusive or incorrect posts, not to contact Customer Service.

[Crucial_FAQ]

Installing memory is easy! If you want to learn how, watch our short installation videos for desktops, laptops, and netbooks.

Desktop PC installation

Laptop installation

Dell Mini 9 Netbook installation

ASUS Eee PC Netbook installation

Apple MacBook installation

[Crucial_FAQ]

The maximum amount of memory that your system can use is actually limited in two ways — not only is there a maximum amount of memory that your computer motherboard can accept, there is also a maximum amount of memory that your operating system (OS) can accept.

For instance, when you install 4GB of memory in a 32-bit Windows system (the most common version; 64-bit systems are typically used only by high-end users), your system will see (and utilize) only 3GB or 3.5GB. Is the problem bad memory?

Relax, there isn't a problem with the memory. Windows allows for 4GB of memory to be addressed, but this isn't 100 percent the same as having 4GB of physical memory.

What happens is that some of the addressable memory (regardless of how much you have physically installed) is reserved for use by page files or by some of the devices that you are using, such as a graphics card, PCI card, integrated network connections, etc., so it's unavailable for use as normal main memory.

The amount of memory needed for these devices is calculated by your system at startup; if you haven't maxed out the memory in your system, it's invisible to you, and all your physical memory (the RAM that's installed) is available for use. However if you've maxed out the DRAM in your system, this amount will be deducted from your physical memory, so you can't use 100% of your DRAM.

The maximum memory limitation varies by operating system; for instance, the 4GB memory limitation doesn't exist in 64-bit versions of Windows.

Memory maximums for current Microsoft® Windows OSs include:

Windows Vista (32 bit)

• Ultimate: 4 GB


• Enterprise: 4 GB


• Business: 4 GB


• Home Premium: 4 GB


• Home Basic: 4 GB


• Starter: 1 GB

Windows XP (32 bit)

• Professional: 4 GB


• Home: 4 GB


• Starter Edition: 512 MB

Windows Server 2003 (32 bit)

• Datacenter SP2: 128 GB


• Enterprise SP2: 64 GB


• Standard SP1: 4 GB*


• Datacenter R2: 128 GB


• Enterprise R2: 64 GB


• Standard R2: 4 GB*


• Web Edition: 4 GB*


• Small Business Edition: 4 GB*

* Certain Microsoft server operating systems can support over 4GB of memory via Physical Address Extension (PAE). Please refer to Microsoft knowledgebase article located here for more information.

Windows Server 2008 (32 bit)

• Datacenter: 64 GB


• Enterprise: 64 GB


• Standard: 4 GB


• Web Server: 4 GB

Windows Vista (64 bit)

• Ultimate: 128 GB


• Enterprise: 128 GB


• Business: 128 GB


• Home Premium: 16 GB


• Home Basic: 8 GB

Windows XP (64 bit)

• Professional: 128 GB


• Windows Server 2003 (64 bit)


• Datacenter SP2: 2 TB


• Enterprise SP2: 2 TB


• Standard SP1: 32 GB


• Datacenter R2: 1 TB


• Enterprise R2: 1 TB


• Standard R2: 32 GB

Small Business Edition: 128 GB

Windows Server 2008 (64 bit)

• Datacenter: 2 TB


• Enterprise: 2 TB


• Standard: 32 GB


• Web Server: 32 GB

[Crucial_FAQ]

The maximum amount of memory that your system can use is actually limited in two ways — not only is there a maximum amount of memory that your computer motherboard can accept, there is also a maximum amount of memory that your operating system (OS) can accept.

For instance, when you install 4GB of memory in a 32-bit Windows system (the most common version; 64-bit systems are typically used only by high-end users), your system will see (and utilize) only 3GB or 3.5GB. Is the problem bad memory?

Relax, there isn't a problem with the memory. Windows allows for 4GB of memory to be addressed, but this isn't 100 percent the same as having 4GB of physical memory.

What happens is that some of the addressable memory (regardless of how much you have physically installed) is reserved for use by page files or by some of the devices that you are using, such as a graphics card, PCI card, integrated network connections, etc., so it's unavailable for use as normal main memory.

The amount of memory needed for these devices is calculated by your system at startup; if you haven't maxed out the memory in your system, it's invisible to you, and all your physical memory (the RAM that's installed) is available for use. However if you've maxed out the DRAM in your system, this amount will be deducted from your physical memory, so you can't use 100% of your DRAM.

The maximum memory limitation varies by operating system; for instance, the 4GB memory limitation doesn't exist in 64-bit versions of Windows.

Memory maximums for current Microsoft® Windows OSs include:

Windows Vista (32 bit)

• Ultimate: 4 GB


• Enterprise: 4 GB


• Business: 4 GB


• Home Premium: 4 GB


• Home Basic: 4 GB


• Starter: 1 GB

Windows XP (32 bit)

• Professional: 4 GB


• Home: 4 GB


• Starter Edition: 512 MB

Windows Server 2003 (32 bit)

• Datacenter SP2: 128 GB


• Enterprise SP2: 64 GB


• Standard SP1: 4 GB*


• Datacenter R2: 128 GB


• Enterprise R2: 64 GB


• Standard R2: 4 GB*


• Web Edition: 4 GB*


• Small Business Edition: 4 GB*

* Certain Microsoft server operating systems can support over 4GB of memory via Physical Address Extension (PAE). Please refer to Microsoft knowledgebase article located here for more information.

Windows Server 2008 (32 bit)

• Datacenter: 64 GB


• Enterprise: 64 GB


• Standard: 4 GB


• Web Server: 4 GB

Windows Vista (64 bit)

• Ultimate: 128 GB


• Enterprise: 128 GB


• Business: 128 GB


• Home Premium: 16 GB


• Home Basic: 8 GB

Windows XP (64 bit)

• Professional: 128 GB


• Windows Server 2003 (64 bit)


• Datacenter SP2: 2 TB


• Enterprise SP2: 2 TB


• Standard SP1: 32 GB


• Datacenter R2: 1 TB


• Enterprise R2: 1 TB


• Standard R2: 32 GB

Small Business Edition: 128 GB

Windows Server 2008 (64 bit)

• Datacenter: 2 TB


• Enterprise: 2 TB


• Standard: 32 GB


• Web Server: 32 GB

[Crucial_FAQ]

Most desktops and notebooks use one of four popular types of dynamic random access memory (DRAM) for the main system memory.

Single data rate (SDR) SDRAM is the older type of memory, commonly used in computers prior to 2002.

Double data rate (DDR) SDRAM hit the mainstream computer market around 2002 and is a straightforward evolution from SDR SDRAM. The most significant difference between DDR and SDR is that DDR reads data on both the rising and falling edges of the clock signal, enabling a DDR memory module to transfer data twice as fast as an SDR memory module.

Systems implementing the follow-on technology to DDR, called DDR2 began to appear in mid-2004. DDR2 achieves speeds beyond that of DDR, delivering bandwidth of up to 8.5 GB per second. Frequently, DDR2 based systems can use memory installed in pairs to run in "dual channel mode" to increase memory throughput even further.

The latest generation of memory technology, DDR3, began to appear in systems in late 2007. DDR3 is an evolutionary step beyond DDR2 and operates at lower voltages, thereby consuming less power, and can transfer data at rates up to 12.8 GB per second. Typically, DDR3 based systems can address memory modules in banks of 1, 2 or 3. If a system supports it, installing memory in matched sets of 2 or 3 modules (dual channel or triple channel modes) will deliver greatly increased memory performance over running a single memory module by itself.

Generally speaking, motherboards are built to support only one type of memory. You cannot mix and match SDRAM, DDR, DDR2, or DDR3 memory on the same motherboard in any system. They will not function and will not even fit in the same sockets.

The right type of memory to use is the one that your computer takes! The easiest way to find the right memory for your computer is to look up your system in Crucial's Memory Advisor tool. The Memory Advisor tool will list only compatible memory for your system.

If you don't know the exact model of your computer, the Crucial System Scanner can scan your computer hardware to automatically detect your system configuration and give you a report on which upgrade is right for you.

[Crucial_FAQ]

PC2-4200 (DDR2-533), PC2-5300 (DDR2-667), PC2-6400 (DDR2-800), and PC2-8500 (DDR2-1066) memory are all types of Double Data Rate, second-generation SDRAM, usually referred to as DDR2. The varying numbers refer to the different speeds of memory your computer was designed for.

Let's take a look at PC2-4200 (DDR2-533) to break it down simply.

PC2-4200 (DDR2-533) refers to the bandwidth of the memory. A PC2-4200 module has the bandwidth of 4.2 GB/sec; therefore, it is referred to as PC2-4200.

DDR2-533 refers to the effective front-side bus speed of your system. While your DDR2 system or motherboard may operate a 266MHz front-side bus, its effective front-side bus speed is 533MHz because DDR2 effectively doubles the amount of data transferred per cycle that a non-DDR2 system would.

The same holds true for PC2-5300 (DDR2-667), which has a bandwidth of 5.3GB/sec and is designed for use in systems and motherboards that require a 333MHz front-side bus, with an effective front-side bus speed of 667MHz. And the same holds true for PC2-6400 (DDR2-800), which has a bandwidth of 6.4GB/sec and is designed for use in systems and motherboards that require a 400MHz front-side bus, with an effective front-side bus speed of 800MHz.

Though DDR2 memory was designed to be backward-compatible (meaning you can use PC2-5300 module in a computer designed to use PC2-4200, or vice-versa), we always recommend that you use the Crucial Memory Advisor tool to find exactly the right memory for your computer