The task of upgrading a server's memory can be very similar to that of a desktop computer but it can also be very different. Neal Nelson, president of Neal Nelson & Associates, explains.
In some ways, a computer is like a car because there are some changes and repairs that owners can perform on their own. Increasing the size of a computer's RAM may be one of these changes. The following six steps will explain how to increase the memory size of your server computer.
CAUTION: By attempting the steps described in this procedure, you may ruin your computer. Pushing too hard, or in the wrong place, can crack the computer's motherboard. A small spark of static electricity can burn out critical computer circuits. Installing a memory module "backwards" can cause short circuits. An improperly "seated" module can prevent the computer from booting when it is powered up. So be careful and good luck.
Step 1: Determine the Current Size of the Computer's Memory
For computers running Windows, Microsoft provides a program called Task Manager that provides a quick display of the system's status. Run this program by clicking the right mouse button while the mouse pointer is positioned on the task bar (which is normally at the bottom of the screen). Then select "Task Manager".
Next, click on the "Performance" tab. Make a notation of the number listed for "Physical Memory (K)
-Total". For computers running Linux, log in as "root" and type the command "cat /proc/meminfo<RETURN>," then note the value for "MemTotal".
Step 2: Locate the Memory Modules in the Computer
Power down the computer and unplug the computer's power cord. Open up the computer case and locate the computer's memory modules. Most computers have DIMMs (
dual in-line memory modules) that fit into DIMM sockets. Look for the DIMMs. Then note how many DIMMs are currently installed, and how many empty sockets remain with no DIMMs installed.
Below is a photo of two DIMMs and two empty DIMM sockets. Most servers with 1U and 2U chassis will have the memory module sockets on the main motherboard. But 4U, 6U and "blade" servers may have memory riser cards or other boards that are designed specifically for memory modules. You might have to search a bit inside these servers to find the memory modules and empty sockets.
Step 3: Plan Your Upgrade
In order to plan your upgrade, you must determine a number of things. Consider the total size of the computer's currently installed memory, the number of DIMMs currently installed, the number of empty DIMM sockets, and the desired increase in memory size. DIMMs are often installed in pairs. Consider adding two 512MB DIMMs if you wish to increase the computer's total memory size by 1GB. You may have to remove some currently installed DIMMs in order to free up slots for the new memory modules you wish to install.
You must also determine exactly what type of memory you need. Types of memory include SDRAM, DDR, DDR2, DDR3, FB-DDR, Registered, Unregistered, parity, non-parity, ECC, non-ECC, 2.2-volt, 1.8-volt and 1.5-volt. There are also a variety of speed grades such as 512, 667, 800, PC-3200, PC-4800 and PC-6400. If you buy the wrong type of memory, the computer may not boot, or you might even "burn out" some components.
Many computer and motherboard manufacturers have copies of manuals online that will provide the specifications for the memory modules which are compatible with the computer. These manuals should also contain notes about any requirements to install memory modules in pairs or in alternating banks.
Step 4: Obtain the New Memory Modules
DIMMs are available from a number of sources. These include the companies that built the computer such as Hewlett-Packard or Dell, retailers such as Best Buy, online merchants such as Dalco Electronics or Newegg, auction sites such as eBay or Craigslist, and special memory Web sites. The safest option is to purchase the new memory from the company that originally built the computer.
Another safe and usually less expensive option is to buy your memory from www.crucial.com. I generally recommend Crucial to someone who is new to upgrading memory. Cruical has an excellent online system to help you find the right memory module. They show the detailed technical specifications for the recommended memory, provide instructions on how to install the memory, offer free shipping, and have a 30-day, money-back compatibility guarantee.
Step 5: Install the New Memory Modules
The installation procedure can be completed in the following steps:
1. Be sure the computer is powered off and the power cord is unplugged.
2. Position the computer chassis so that you will be able to press the DIMM into the socket with straight-down, firm and even pressure. I like to lay the chassis down flat on a strong table or on the floor, so that I can lean over the chassis when I press straight down.
3. Wear an anti-static wrist strap or touch the chassis frequently to drain static electricity.
4. Flip open the retaining clips at each end of the DIMM socket.
5. Orient the DIMM properly. The notch on the DIMM should be aligned with the corresponding bump in the socket.
6. Press the DIMM into the socket by pressing with one thumb at each end of the DIMM. There will often be a "click-click" sound as the DIMM seats down into the socket and the retaining clips snap into position. But be careful. If you press too lightly or unevenly, the DIMM will not "seat" correctly. It will not make proper electrical contact. And if you press too hard, you can ruin the motherboard by cracking it. The photo below illustrates this step.
Step 6: Test for Proper Operation
Next you should test to see if everything is operating correctly. Connect the computer's power cord and boot the machine. Repeat Step 1 to check that the new memory size agrees with your expectations. You might also want to run a thorough diagnostic test of the computer's memory. There are some low-cost and free test programs available from www.memtest86.com and www.memtest.org. Consider executing the test for many hours (such as overnight).
Step 7: Possible Problems
If there is a problem during the upgrade, the computer may display a smaller-than-expected memory size, or it may not boot at all. Check very carefully to see if the DIMMs are properly seated in the sockets. You might also need to check that you have not accidentally bumped some other card (such as the computer's video card) so that it is no longer properly seated in its slot.
Try removing the new DIMMs and booting with the original memory configuration. Consider contacting the company that sold you the memory. They might have a support center that could help you solve the problem. If all else fails, it would be time to call in professional help.
A memory upgrade is a procedure with medium difficulty and moderate risk. But it is also one that can provide significant benefits for a modest cost. As I said in the beginning of the article, be careful and good luck.
Neal Nelson has more than 35 years experience with all aspects of complex computer systems. As the Chief Developer, Owner and President of Neal Nelson & Associates, an independent hardware and software performance evaluation firm, he has tested more than 500 computer systems. A Web site with some of his test results can be found at www.worlds-fastest.com. He can be reached at firstname.lastname@example.org.