All Rights Reserved. Copyright Privacy Policy Sitemap Contact us on : info infibee. The spine of the computer is the system board, otherwise known as the motherboard. We spent an hour one day trying to figure out why a system we'd built just sat there beeping instead of booting. Turned out that we'd forgotten to install the CRIMM, which was buried deep in the motherboard packaging.
You must install memory at least one full bank at a time. If you install more than one bank, you must install in full-bank increments.
One pin SIMM equals one bank in s and s. Older systems, particularly s, may interleave banks to improve performance, which requires installing two banks at a time. Most such motherboards can operate with only one DIMM installed, but that disables dual-channel memory operation, which may incur a significant performance penalty. See the motherboard manual for complete details. In addition to banks, you may need to consider rows or devices , particularly if you install a large amount of memory.
Each SDRAM chipset supports at most a given number of rows of memory, and this limit does not necessarily correspond with the number of physical memory slots on a motherboard that uses that chipset.
So, for example, if a motherboard has three physical DIMM slots and its chipset supports only four rows of memory, you are restricted in terms of which DIMMs you can install. But if you install two double-sided DIMMs, you must leave the third slot empty because the two double-sided DIMMs total four rows, which is the maximum the chipset supports.
Installing faster memory may reduce the number of DIMMs you can install. Using too much fast memory can cause subtle memory problems. Motherboard, system, and memory manufacturers often do not publicize this problem. As a rule of thumb when installing fast memory, choose fewer high-capacity modules in preference to more lower-capacity modules. This problem is particularly likely to arise when you "push the envelope"? There is an upper limit on how many memory chips the memory controller can manage, which restricts the total number of unbuffered memory chips that the motherboard can support.
A motherboard that supports either type may allow using one or the other, but not both at once. RDRAM systems also limit the number of memory chips that can be installed at one time. Attempting to install a third RIMM on that system would cause the system to fail to boot. Conversely, if you were installing RIMMs that use eight devices, three RIMMs would total only 24 devices, and so would be within the device limitation of that channel. Memory modules are constructed from individual memory chips, which vary in their capacity.
Chip capacities are specified in megabits Mb or Mbit rather than megabytes MB. Because there are eight bits per byte, a memory module that uses eight chips can store the number of megabytes specified by the megabit size of the chip. For example, a memory module that uses eight Mbit chips is a MB memory module. Recent memory modules may use , , , , or Mbit chips. A memory module of a specified capacity may use fewer high-capacity chips or more low-capacity chips.
For a given capacity, it's generally better to install a single-sided DIMM when possible because chipsets support only so many rows of memory, and a double-sided DIMM "uses up" two rows. However, you must not install memory that uses higher-capacity chips than your chipset supports. For example, the Intel chipset supports , , , and Mbit chips, so an based motherboard could use either the eight-chip or the chip, MB DIMM.
Attempting to install a DIMM that uses higher-capacity chips than the chipset supports has unpredictable consequences. Sometimes, the system will simply refuse to recognize the DIMM. Other times, the system will recognize the DIMM, but at some fraction typically one-half or one-quarter of its actual capacity.
They will not function and will not even fit in the same. Which means the chip reads or writes two words of data per clock cycle. It is a medium sized memory module used in a newer model desktop PC. In most cases, yes. Log in.
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To understand latency, take a look at the difference between serial and parallel transfers. Think of a train in a movie scene. The hero is at one end of the train and has to chase the bad guy, using a serial process. He goes from one end of a car, along all the seats, and then leaves by a door at the other end, which is connected to the next car in the train.
Then the process starts all over again, until he either reaches the end of the train or someone gets killed. Now take that same train, but this time there isn't a hero chasing a bad guy. Instead, imagine a train full of people on their way to work. If there was only one door at the back of the train, it would take forever to let everyone off at the train station. To fix that problem, each car has its own door. When the train comes to a stop, everyone turns to the side facing the platform: The doors in each car open up, and people leave each car simultaneously.
This is a parallel transfer. RDRAM uses a bit bus for the data signals. Keep in mind that transfers are not only faster, but there are two of them per cycle. On the other hand, one of the problems with parallel transfers at high speeds is something called skew. The longer and faster the bus gets, the more likely it is that some data signals will arrive too soon or too late: not in a perfect line.
It would be as if sixty-four people started to leave the train at the same time, but each one stepped onto the platform at a different time. With no licensing fees, it's also cheaper to produce. Note that modern Intel chipsets use two parallel Rambus channels to reach 3.
AMD wasn't going to be limited to an Intel board, so much of the market jumped on the Via chipset. This put pressure on Intel to come up with a modified series chipset that would also support DDR memory. It appears as though Rambus may have a hard battle to win market share, but it continues to hang on in high-end desktops and workstations. In a nutshell, fast and long may not be the same as slow and short. For instance, suppose you want to go two miles to the store.
If you go the long way, using a highway, it's a ten-mile drive. However, you can drive 60 mph on the highway. If you go directly to the store, you're stuck driving 30 mph on local roads. You might drive a whole lot faster on the highway, but you'll get to the store faster on the straight-line route. In this example, the store is the memory controller. The different roads represent different types of bus architectures.
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