Knowing How Much Is Enough 434 megadollars for my most recent bathing-suit modeling session, you should reasonably understand that to mean $2 million. (And I’m worth every drachma.) But as I explain in Book I, Chapter 3, computers use an entirely different form of math. To begin with, they don’t have ten fingers. But more to the point, a modern computer accomplishes its magic by applying brute force to just two numbers: 0 or 1. It’s called binary math. (Yes, I know 0 isn’t a number; it’s the absence of a value. But that’s human thinking, not computer thought.) The money in our wallets—leather or virtual—is mostly measured in parts of ten. Inside a computer, it’s all parts of two. To be more precise, binary math is applied to computer “words” made up of 8 or 16 or 32 digits. An 8-digit word made up of either 0s or 1s can range in size from 0 (00000000) to 255 (11111111); to the computer that means 256 possible values. String together two of those words, and you’ve got 512 possible values; a group of four offers 1,024 variations. When you referring to computer words, also known as bytes, you call that last value a kilobyte. Do you see the problem yet? A kilobyte would seem to mean a thousand bytes, but it’s actually 1,024. When you talk about small numbers, it’s an error (or at least a misunderstanding) of only about 2 percent. But consider the difference between a decimal understanding of a gigabyte of 1,000 3 (1,000,000,000 bytes) and a binary accounting of 1,024 3 (1,073,741,824 bytes). Up there amongst the gigabytes, the difference is more like 7.5 percent. So, when you buy a gigabyte of RAM, are you getting 1,000,000,000 bytes or 1,073,741,824 bytes? Well, when you’re dealing with RAM, the answer is neither. The raw capacity is actually 1,024 3 , although perhaps 10 percent of the RAM is taken up with overhead, including indexing and error checking; however, when you buy 1GB of memory, you’re really getting that number of memory locations in true binary math — 73.7 million more than a mere billion. But things get squirrelly in hard disk drive measurements. Here the market- ing department gets involved. Sometimes a drive is measured in decimal math and sometimes in binary math, and always in terms of what sounds like a larger and more saleable product. In Table 7-1 you can see a table that translates common binary math terms. I present both bytes and bits; a computer byte or word is made up of eight bits. Table 1-1 Binary Math Abbreviation Meaning Value Kb Kilobit 1,024 bits KB Kilobyte 1,024 bytes 34 140925-bk07ch01.qxp 4/8/08 12:50 PM Page 434 Book VII Chapter 1 Adding RAM Using Your Brain When Buying Memory 435 Abbreviation Meaning Value Mb Megabit 1,048,576 bits MB Megabyte 1,048,576 bytes Gb Gigabit 1,073,741,824 bits GB Gigabyte 1,073,741,824 bytes Tb Terabit 1,099,511,627,776 bits TB Terabyte 1,099,511,627,776 bytes Pb Petabit 1,125,899,906,842,624 bits PB Petabyte 1,125,899,906,842,624 bytes Eb Exabit 1,152,921,504,606,846,976 bits EB Exabyte 1,152,921,504,606,846,976 bytes Zb Zettabit 1,180,591,620,717,411,303,424 bits ZB Zettabyte 1,180,591,620,717,411,303,424 bytes Yb Yottabit 1,208,925,819,614,629,174,706,176 bits YB Yottabyte 1,208,925,819,614,629,174,706,176 bytes Don’t throw away excess memory that you remove from a laptop as part of an upgrade project. Give it to a school or a community organization. If you must, sell it through an online auction site. Someone, somewhere can use it. Using Your Brain When Buying Memory You must take four critical first steps before buying memory for a laptop computer: 1. Determine the memory type and kind of module or holder it’s mounted on. 2. Find out the maximum amount of memory your machine is capable of managing. 3. Know the total number of sockets available for module installation. 4. Find out how much memory is already installed in the machine and what configuration is used. Is all the memory on one module? Are two modules of equal size already installed? Are two unequal modules in place? Most of today’s current machines use tiny postage stamp-sized modules called SODIMMs (Small Outline Dual In-line Memory Modules). That means small pieces of memory on a stick with a tiny set of 200 connectors at the bottom that plug into a matching socket. 34 140925-bk07ch01.qxp 4/8/08 12:50 PM Page 435 Using Your Brain When Buying Memory 436 You must match the exact type of memory and module to your machine’s needs. You can find the necessary details by consulting the instruction manual for your machine or by visiting a number of online web sites for memory vendors; the best of them allow you to enter the model number or part number of your laptop (you find both on a label on the underside of your machine) and receive a report about compatible devices. For this book’s sample Toshiba Satellite P205, the proper memory is a DDR2 SDRAM (double data rate 2 synchronous dynamic random access memory) module. You don’t really have to know exactly what all of the jargon means; in almost every machine you just need to match the description and specifi- cation exactly; you can’t upgrade or change the memory module design for a laptop motherboard. In general, memory modules are marked with a MHz (megahertz) speed or with a PC rating such as PC133. The higher the speed rating, the faster the chip or module can operate. I’m talking about tiny incremental differences, and once again, you have little or no choice: You have to match the specifi- cations of your laptop’s motherboard. (In a few cases you may be able to install modules of a faster speed than your laptop can handle, or a second module that’s faster than the first one already in place. Either way, the machine will operate no faster than the slowest component or specification.) Do so only if you have no other option; mixing and not matching is a potential headache. As delivered from the factory, this particular model can ship with as little as 256MB, which is way too little to run current versions of Windows. A bit of research into the machine’s specs tells me two sockets are available for memory; I could have also opened the hatch on the bottom of the box to see for myself. (You may also be able to use an online scanning tool offered by your laptop maker, or by memory vendors like Crucial through their web site www.crucial.com.) The only reason to buy the machine with the minimum amount of RAM is if you can save a lot of money by removing the memory already in place and install modules you purchase on your own. That used to be a reasonable strategy, but today the prices of RAM have declined so much, often it’s less expensive to buy a new laptop fully fitted out with the amount of memory you want to have, hold, and use. Here’s the problem: You buy a machine with 1GB of RAM installed and you want to run the laptop with 2GB of memory. If the machine, as delivered, has two 512MB modules in place, you’re going to have to remove and replace one or both. You could install a single 2GB module, two 1GB modules, or keep one of the 512MB modules and install a 2GB stick in the other slot for a total of 2.5GB. 34 140925-bk07ch01.qxp 4/8/08 12:50 PM Page 436 Book VII Chapter 1 Adding RAM Using Your Brain When Buying Memory 437 Knowing where to go Sometimes the best price comes if you purchase your laptop fully equipped with the amount of memory you want. Laptop makers buy memory in huge quantities, and their prices are sometimes reasonable. And be sure to calcu- late the lost value of any memory modules you may have to remove if you upgrade by yourself. To buy from third-party sources, shop at places that treat memory as a com- modity: online stores, catalog marketers, and computer superstores. In the early days of computerdom, it generally made sense to spread out your memory across several modules to reduce the chances of failure. Current memory modules, though, are pretty well tested and reliable. The chips themselves are less likely to fail than the module that holds them, the socket on the motherboard, or the wiring to that socket. Today, go large. Memory makers use an unpleasant but accurate term about the function of modules: infant mortality. If a stick is going to fail, most likely it’s either dead on arrival — very rare since factories test them — or fail within a few hours or days of installation (after going through a few cold-to-hot-to-cold cycles). Pay attention to the price variations caused by supply and demand. A 2GB module should, in theory, cost a bit less than two 1GB modules because it requires only one circuit board, connector, and packaging. Sometimes, though, a particular size of memory module may be out of whack because of shortages or high demand. Checking up on your memory If you watch very, very carefully you may be able to watch the numbers fly by onscreen as your laptop boots up. This is one way — not a very accurate or easy one — to see how much memory is recognized for use by your machine. There are better ways. This is an easier way to obtain a report on installed (and useable) memory: 1. Go to the System Properties report within Windows. 2. Click the Start button and then choose Control Panel. 3. Double-click the System icon. Under Windows Vista you see a declaration of the amount of RAM in the system section. Under Windows XP you see the complete System Properties report. 4. Click the General tab. Now you can see the amount of installed memory recognized by the system. 34 140925-bk07ch01.qxp 4/8/08 12:50 PM Page 437 Using Your Brain When Buying Memory 438 Another, more involved and more accurate way to examine the memory in your machine is to run a test on the system. Most laptop makers provide at least a basic test utility. Toshiba’s PC Diagnostic offers a report on compo- nents, as seen in Figure 1-1. One step beyond, you can ask the system to test any selected pieces of hardware; this particular utility gives you only a Pass- Fail report, which is okay if you receive all passing grades; if problems crop up, you need additional tools. A report on a properly functioning machine is shown in Figure 1-2. Figure 1-2: A diagnostic test puts all a laptop’s major components through a series of basic tests that can reassure you (or start you on a bug hunt). Figure 1-1: A diagnostic program, in this case provided by Toshiba to laptop customers, offers a detailed report on installed hardware, including installed memory. 34 140925-bk07ch01.qxp 4/8/08 12:50 PM Page 438 Book VII Chapter 1 Adding RAM Cramming Some RAM in a Laptop 439 Cramming Some RAM in a Laptop The general process of installing memory modules in a laptop is very similar from one brand to another; today, nearly every laptop design places an access panel on the bottom of the machine and uses similarly latching sockets. The description I use here is from the sample Toshiba Satellite P205 laptop. You want to make sure that the machine has no electrical power and is cool and stable. Take these preliminary steps: 1. Turn off the computer using the Windows shut-down process. You lose stored data if you use Sleep or Hibernation mode. 2. Unplug the AC adapter cable that runs to the laptop. Why remove the AC adapter and the battery before installing memory modules? First of all, plugging them in while power is on could result in damage to the RAM. Secondly, doing any work on a laptop while power is applied could result in a damaging spark. 3. Remove the battery. 4. Disconnect any other cabling to the laptop, including an Ethernet cable or a telephone modem wire. If the machine has been running recently, allow it to cool for about 15 minutes; memory modules can become quite hot when they are in use. 5. Locate a small Phillips-head screwdriver. A screwdriver with an X-shaped head; make sure it’s in good condition and not chewed up or misshapen. 6. Place a soft cloth or other protective mat on a desktop. 7. Turn the laptop over so that its bottom is facing up. 8. Locate the memory module slot cover. For an example of a typical arrangement, see Figure 1-3. 9. Carefully remove the screw that holds the cover over the memory compartment. Hold the screwdriver at a right angle to the bottom of the laptop and turn the screw carefully; it shouldn’t require a lot of force to remove. Once the screw is removed, put it in a safe place. Use a piece of clear tape to attach it to the desktop or the side of the computer. 10. Ground yourself before touching the memory module. Touch any grounded metal surface, like a light stand, or touch the center screw on an electrical outlet. 34 140925-bk07ch01.qxp 4/8/08 12:50 PM Page 439 Cramming Some RAM in a Laptop 440 Courtesy of Toshiba America, Inc. Removing a memory module Here are the steps for removing a memory module: 1. Carefully release the latches on the side of the module holder. 2. Lift it to an approximately 30-degree angle from the bottom surface of the laptop. 3. Gently slide the module out of its connector and out of the slot. This step is shown in Figure 1-4. Installing a module into an empty socket These steps help you install a module into an empty socket: 1. Carefully remove a new memory module from its packaging. Avoid touching the connectors; doing so can reduce conductivity because of oils on your finger. Figure 1-3: Proper technique for removing the memory module cover on the bottom of a laptop. 34 140925-bk07ch01.qxp 4/8/08 12:50 PM Page 440 Book VII Chapter 1 Adding RAM Cramming Some RAM in a Laptop 441 Courtesy of Toshiba America, Inc. 2. Locate an empty module slot. If two sockets are in the compartment and the top one is filled and the bottom is empty, remove the top module first. 3. Pick up the memory module by its sides and aim its connectors toward the socket. Be sure to align the notch in the connector with the matching key in the socket. See Figure 1-5. 4. Slide the module into place. Most sockets align at about a 30-degree angle. 5. Once the module is fully inserted into the socket, press down on the top edge of the device to latch it into place. This way it’s flat to the laptop’s bottom. The carrier should snap into place with latches. See Figure 1-6. 6. Replace the memory compartment cover and lock it down with the screw. Don’t overtighten the screw. Figure 1-4: Lifting up a memory module holder and removing the memory. 34 140925-bk07ch01.qxp 4/8/08 12:50 PM Page 441 Cramming Some RAM in a Laptop 442 Courtesy of Toshiba America, Inc. Courtesy of Toshiba America, Inc. Going post-installation Here’s what you do after installing memory: 1. Reinstall the main battery. 2. Turn the laptop right-side up. 3. Reattach the AC adapter cable and other connections. 4. Restart the computer. Figure 1-6: Gently push the module, in its carrier, back to a flat position on the bottom of the laptop. It should gently latch into place. Figure 1-5: Align the notch in the connector of the memory module with the correspon- ding key in the socket. 34 140925-bk07ch01.qxp 4/8/08 12:50 PM Page 442 Book VII Chapter 1 Adding RAM Flashing for ReadyBoost Memory 443 Flashing for ReadyBoost Memory With the arrival of Windows Vista — and a particular design of motherboard and chipsets — Microsoft introduced a new way to add a block of memory to your system by plugging in an external flash memory key (or even a memory card or stick like the ones used in digital cameras and audio players). It’s called Windows ReadyBoost, and it uses flash memory — a form of non- volatile memory — as a place to temporarily hold some of the information retrieved from disk reads. The data on the external block of memory is recorded in a special format that, to the system, is easier to access than if it were kept on the internal hard disk drive. As part of ReadyBoost technology, the Vista operating system offers redun- dant protection: At the same time the information contained in disk reads is recorded to attached flash memory, it’s also written to a reserved segment of your hard disk drive. In technical terms this is known as a write-through cache. This protects against information loss if the flash memory key is removed from the system. Now if you think about it, recording data to an easily removable piece of hardware like a flash memory key represents a pretty serious threat to data security. If the external memory were stolen or lost, an unauthorized person might be able to read its contents. To guard against this, Vista automatically applies encryption to the data on the key, making it difficult, if not impossi- ble, for it to be misused. Some other fancy tricks are applied to the process. Because it’s non-volatile, flash memory is a bit slower than ordinary RAM when it comes to writing data. And in some circumstances it responds more slowly than a hard disk drive. But in actual use, the relatively slow ReadyBoost memory response is mostly a factor when it comes to reading lengthy, sequential files such as music or streaming video. To deal with this, Windows Vista takes a quick look at the size and nature of files, and ReadyBoost technology automatically diverts Vista’s attention from the flash memory to the hard drive if it’s called upon to work with oversized files. Looked at the other way, ReadyBoost is at its best when it comes to working with small blocks of information. As a RAM device, even a relatively slow flash memory key still delivers information faster in most cases than a hard disk drive (which has to wait while its read/write heads are moved to a par- ticular location and then wait again for the spinning platter to bring the needed data into view). 34 140925-bk07ch01.qxp 4/8/08 12:50 PM Page 443 . a lot of force to remove. Once the screw is removed, put it in a safe place. Use a piece of clear tape to attach it to the desktop or the side of the computer. 10. Ground yourself before touching. memory — a form of non- volatile memory — as a place to temporarily hold some of the information retrieved from disk reads. The data on the external block of memory is recorded in a special format. can find the necessary details by consulting the instruction manual for your machine or by visiting a number of online web sites for memory vendors; the best of them allow you to enter the model