DDR SDRAM or double-data-rate synchronous dynamic random access memory is a class of memory integrated circuit used in computers. It achieves greater bandwidth than the preceding single-data-rate SDRAM by transferring data on the rising and falling edges of the clock signal (double pumped). Effectively, it nearly doubles the transfer rate without increasing the frequency of the front side bus. Thus a 100 MHz DDR system has an effective clock rate of 200 MHz when compared to equivalent SDR SDRAM, the “SDR” being a retrospective designation.

With data being transferred 64 bits at a time DDR RAM gives a transfer rate of [mbcr x 2 x 64] / 8; annotated it looks like this: (memory bus clock rate) ? 2 (for dual rate) ? 64 (number of bits transferred) / 8 (number of bits/byte). Thus with a bus frequency of 100 MHz, DDR-SDRAM gives a max transfer rate of 1600 MB/s.

JEDEC has set standards for speeds of DDR SDRAM, divided into two parts: The first specification is for memory chips and the second is for memory modules.

About DDR2

In electronic engineering, double-data-rate two synchronous dynamic random access memory (DDR2 SDRAM) is a random access memory technology used for high speed storage of the working data of a computer or other digital electronic device.

It is a part of the SDRAM (synchronous dynamic random access memory) family of technologies, which is one of many DRAM (dynamic random access memory) implementations, and is an evolutionary improvement over its predecessor, DDR SDRAM (double-data-rate synchronous dynamic random access memory).

Its primary benefit is the ability to run its bus at twice the speed of the memory cells it contains, thus enabling faster bus speeds and higher peak throughputs than earlier technologies. This is achieved at the cost of higher latency.

Like all SDRAM implementations, DDR2 stores memory in memory cells that are activated with the use of a clock signal to synchronize their operation with an external data bus. Like DDR before it, DDR2 cells transfer data both on the rising and falling edge of the clock (a technique called double pumping). The key difference between DDR and DDR2 is that in DDR2 the bus is clocked at twice the speed of the memory cells, so four words of data can be transferred per memory cell cycle. Thus, without speeding up the memory cells themselves, DDR2 can effectively operate at twice the bus speed of DDR.

The iPhone is basically a smartphone built with multimedia capabilities, internet connectivity, as well as a 2.75G quad-band GSM network connection system. It has an integrated 2.0 megapixel camera, Wi-Fi connectivity capabilities, and an impressive touch screen user interface system, with a virtual keypad as its main “mobile phone” input system. The phone’s touch system is known for its cutting edge technology, which is in itself a standard bearer for the said technology. Its storage features are quite impressive, boasting a 4 gigabyte and 8 gigabyte model for potential users to choose from. It comes with an internal iPhone battery, which powers the iPhone impressively, the raw power fueling the iPhone and its boasted features.

The iPhone battery has a talk time rating of up to eight hours, an internet usage time of six hours, video playback time of seven hours, twenty-four hours of music playback, and two hundred fifty hours of standby time power.

The iPhone battery stands to outperform the batteries of its leading competitors, easily. With the iPhone battery’s eight hours of talk time, it beats Nokia’s N95 by half, as the Nokia N95’s talk time life lasts four hours. The Samsung Blackjack has a talktime rating of 5.5 hours, the Blackberry Curve 8300 with its 4 hour talktime rating and the Palm Treo 750 with a 4 hour talktime rating, are all outperformed by the iPhone battery.

The iPhone battery is truly impressive.

But, though it’s impressive state of nature, there is one particular downside which it looses to its leading competition: the iPhone battery is non removable. It is internal.

Traveling with an iPhone would therefore mean having to bring one’s travel charger along, as there are no removable batteries available. Unlike most smartphone models, which are powered by removable batteries, low iPhone battery statues have to be resolved by charging them. Most smartphone users, using “the usual” smartphones, purchase extra batteries for those in case of emergency situations. With the iPhone battery, this isn’t possible.

Another major issue with the iPhone battery is that eventually, it’s charging cycle would eventually die out. One would have to bring one’s iPhone to an official iPhone shop, or iStore to have one’s iPhone battery changed.

So there you have it. The iPhone battery. Powerful, but with one weakness.
Please check out NetArticlescom for useful tips and info about Cellphones and GPS.

By: Marlene Deidre, VOIP

Use of UPS will provide the time to save the data and to properly shut down the computer. A UPS, however, can be used to offer uninterrupted power to equipment usually for 5 to15 minutes until a utility power is restored or auxiliary power supply can be turned on. If you purchase a UPS, then it is obvious that you will have some UPS accessories- Replacement Battery, Power Distribution Strip, Battery Cabinet, Spare Parts and etc.

Replacement Battery- One of the demanded UPS Accessories is Replacement Battery which is available with a number of benefits such as maintenance-free, leak proof, lead-acid battery with suspended electrolyte. With the usual life-span of 3 to 5 years, a battery is generally replaced after 3 to 5 years.

Power Distribution Strip- Other frequently demanded UPS accessories are Power Distribution Strip which is a convenient solution for applications in which numerous AC outlets are required without surge or line noise protection. It is perfect for increasing inside rack enclosures or on walls, workbenches and more.

Battery Cabinet- Battery Cabinet is also considered as an important UPS accessory. The Battery Cabinet is a gigantic block battery cabinet that comes with pre-installed batteries. It can be used with all the basic battery or in combination with a Power Array Battery Frame to provide longer runtime and safeguard some advantages of the Power Array.

In order to avail best UPS accessories, one can carry out extensive research on the Internet as there are various online stores offering UPS accessories at quite reasonable price.

Thanks http://www.datapowerprotection.co.uk/

The first factor that you should look for when you are thinking about updating your IT network is speed. When it becomes difficult to send things over your network or when larger files start having real slow downs, this can be an indication that it is time to update. Make sure that you are not confusing this with actual services being slow; if the Internet service is slow, it is not something that your networking will fix, so look for where the slowdown is occurring. You may find that it is a specific server that is slow, or it might be because the overall network traffic is too high. Once you have figured out where the slowdown is happening, you will then be able to decide what to do.

Another indication that is time to upgrade your IT network is when you have plans to change the use of your IT network. For instance, are you planning to add a high bandwidth application to your network? If you are suddenly going to be offering streaming media of some sort, an upgrade to your IT network might be essential. Consider how the traffic is going to affect the way that your network runs. While in some cases you can choose to use applications that will keep the impact small and manageable, many older systems are such that a complete replacement might be necessary.

The issue when it comes to replacing your IT network is that you need to do it before something disastrous happens. Computer networking is something that forms the backbone of so many businesses these days and when they go down, they tend to take productivity with them. When an IT network starts failing, it will tend to do it in small problems that gradually snowball into large avalanches, and sometimes it can really sneak up on you. It is possible to get lulled by small problems that seem easily fixed until suddenly they can’t be. Make sure that you are aware of your network, of how old it is and of the quality of the parts that were used. This can make a huge difference when the choice to update it comes up.

Consider what your options are when you are thinking about updating your IT network. There are many choices in front of you and making a good one about your network can save you a lot of grief later on down the line.

By: Derek Rogers, Prodec.co.uk

Though all computer owners and most electronic users know that computers and other electronic items use memory, not many people actually know how the memory actually works.

Any type of electronic storage is technically known and classified as memory. The purpose of memory is to store information and to retrieve it quickly when called upon. If a computer did not have access to memory, it would virtually take you a great deal of time call any program to action. In fact, it could take very long lengths of time that could hinder your progress. This could vary from minutes to hours. However, computer memory “remembers” everything that you have called into action before and saves those details. Therefore, when you click on a program to open it, it automatically pulls it from its memory in seconds and then opens the program for you. This is why computer memory is so important.

Your computers Random Access Memory goes to work the instant you turn your computer on. As soon as your computer is turned on it immediately checks you computer to make sure that all the components which you have set to automatically start are called into action. It also calls upon your operating system to open and run your personal settings the moment you computer turns on.

From there your computers Random Access Memory will follow the commands of your keystrokes and mouse clicks in order to carry out every function that you desire your computer to do. It will then collect the information which you type in and will place it in its Random Access Memory in case you call upon the same set of actions again. This will allow your computer to respond more quickly the next time you carry out the same actions.

Computer memory is one hundred percent necessary to operate your home or business computer. The more memory that you computer has the faster that you computer will run and the more stable that your computer system will be. When you computer begins to run out of free Random Access Memory (RAM) you computer may begin to run slowly, or may become very unstable.

This is why it is always important to keep an eye on how much Random Access Memory (RAM) is already in use on your computer. If you notice that you are reaching or nearing your computers memory limits, then you will want to upgrade and add more memory to your computer system.

By: Katherine Johnson, ]]> http://www.maluzhiyao.com/?feed=rss2&p=35 http://www.maluzhiyao.com/?p=33 http://www.maluzhiyao.com/?p=33#comments Thu, 09 Apr 2009 16:34:56 +0000 admin http://bak.localhost/?p=33 Have you ever had the need to replace your monitor? Did you ever wonder why monitors breakdown suddenly without known reason? Computer parts such as the computer monitors, keyboards, speakers, case fans, and LCD panels are some of the parts that need replacement at some point in your ownership. Where is the best place to buy these computer parts? How do you determine if you are buying high quality and reliable replacements? Often, computer owners simply visit stores that offer cheap replacements. Without looking at the capacity and brand of the parts, they check only the price per unit. Although getting a good bargain out of cheap parts, what is the guarantee that you are getting the value of your money?

By: Mikey Smith, fast-tek.co.uk

We all know that the Macintosh or Mac has serious issues with memory drive and memory space. But there is an apt solution to the same. If you are tired of those errors that continuously plague your screen with the message like Memory Low! And similar kinds then you should go for boosting up with Internal Drive for Mac or IDE Drives for Mac. The Mac otherwise carries an excellent state-of-art look available on the front end but the only problem for a regular computer savvy person who has ever expanding file system and archives important document on his PC is with the Memory of Mac. The IDE Drives for Mac and Internal Drive for Mac come with all density specifications and we must choose according to our need.

The usual problem with people is that they do not know where to shop these products from even after they identify the right hard disk type for themselves. Luckily, Internet as covered all the nooks and corners of Human lifestyle. At one click of your mouse you can order whatever you wish to buy. So if you are looking for buying such PC hard drive expansions like PATA Hard Drives, RAID Solution, SATA RAID Solution, Internal Drive for Mac or IDE Drive for MAC then you should already be searching net for a website that offers all these without any hassle. There are a number of websites available online which host a range of these products and are well trusted amongst people who are regular to the internet shopping. The computer that I am using to draft this article also used to give me trouble each time I used to try to access the files on my D Drive. So I bought RAID SATA Solution from one such site over the net and I was delivered the package the very next day with the installation guide! Much thanks to the Internet!

By: kevin jsmith, transintl.com

Acer Aspire One
From experience, Acer have produced some type of laptop in price that relatively not expensive. The small laptop computers from Acer have been known as Acer Aspire One. The design and features are fulfilling the needs from user. It’s not for heavy computing, but for email, writing, browsing, it’s completely satisfying. And that’s not a big deal with the internet connection. You can just plug and play the internet device, and your browser can work directly.

Asus Eee
Asus has come with its small laptop computers with Asus Eee. It has 160GB of Hard Drives, 4 cell battery, and can give 5 hours battery lifetime. The cons come from its keyboard. It’s so tiny and not comfortable to type. But it’s not a problem, you can use external keyboard that comfortable with you. This product comes with many types. Just pick up as what you need.

The Asus Eee may be designed for children or older customer. But it’s a best option for those who search a lightweight budget PC.

HP Mini-Note
The design from HP Mini-Note as HP Small Mini Laptop Computers is confiscate public attention. It is so stylish and has professional looks. And more, it has a wide size keyboard, almost 90 from its place, then, big hard disk capacity space, and beautiful screen.

But in other hand, the processor is slow. If you use the Vista Operating System, the speed is not good enough. And the design from its touch pad is rather weird because left and right click is not in the usual position.

Conclusion

Three types above have its pros and con. Consider what do you need and what feature you want to have before deciding.

Using Small Laptop Computer can be a good option for those who need mobility, simplicity, and even for small budget investment. Even though Small Mini Laptop Computer specification is maybe not as powerful as the ordinary laptop, but it will act as useful as the ordinary laptop.

By: Imanuel Henry Cahyono, Small Laptop Computers

From the famous known laptop manufacture, HP, comes HP Pavilion tx2130ea types. It’s a convertible and tablet PC with so many features. From the lightweight laptop class, it’s unique because HP Pavilion tx2130ea type is the only one tablet PC. Using in tablet mode is so efficient. You can use it everywhere to write your document comfortably. It has an infrared sensor on each side of the display that makes the touch screen more accurate to follow the movement from the pen.

AMD 2GHz Turion 64 X2 Mobile TL-60, 2GB DDR2 SDRAM, 250 GB HDD 5400 RPM, 12.1″ TFT, Nvidia GeForce GO 6150, Wireless LAN, Gigabit Ethernet, 3 USB Port, 2.2kg of weight, Vista Home Premium Operating System

Pros

The keyboard mode is good. It’s having a big knob that responsive and quite strong so that gives the comfortable zone for typing. The design is stylish with silver and gloss-black color. It can come with cute size, but it has DVD-RW Drive that can write into 3 format of DVD, 5-in-1 card reader, good internet connection through Wi-Fi and Ethernet Gigabit.

The battery comes with four-cell and eight-cell. The eight-cell battery doesn’t add much to the laptop dimension and profile a useful handle when using it in tablet mode. And for those who likes to playing games or watching TV using TV tuner, this produce a sharp pictures.

Cons

The AMD Turion is good enough for multi-tasking and daily application, but it’s a little bit slower than other processor. The battery lifetime is just for 2 hours (in full condition). The touch pad’s is rather inaccurate in pointer movement. For color reproduction it’s not too good.

Overall

This HP laptop computer is a niche product and in line with its price. It can be said that HP Pavilion tx2130ea is comfortable and complete. The touch screen panel gives extra function. Even though, the performance is not as good as other type in this class. If you’d like a Tablet PC but don’t want to do away with a keyboard, it’s a good buy. And for presentation, it has no doubt that you can impress when presenting demonstrating item, writing on the screen with this excellent little machine.

By: Imanuel Henry Cahyono, laptop-rentals.us

Brands like Cisco are keeping in touch with the second-hand market place. As more reports crop up on the dangers that modern electronics pose to the environment, manufacturers are getting on board to support a viable used network equipment market. Second-hand Cisco products can provide the reliability and price points that many organizations are looking for from their network infrastructure. To maintain the quality that Cisco stands for they have put together a certification process for technician working on their products. These certification programs ensure that new Cisco network equipment is installed and maintained according to design specifications. The certification also allows technicians to maintain and appraise pre-owned Cisco equipment. This emphasis on quality standards has led to a revolution in the pre-owned network hardware market not unlike what happened when Toyota backed pre-owned vehicles in the used car market.

Many companies miss the opportunity to squeeze the residual value out of their network hardware before they unload it. Progressive network hardware companies are answering this problem by offering Cisco buy back programs that allow companies to turn their used equipment into cash and avoid any environmentally unfriendly disposal methods. These third party companies will have Cisco certified technicians inspect your equipment and offer an appraisal of its value. Many times companies offering buy back programs will even send a technician to your offices for an onsite consultation and appraisal. While many companies offer buy back services, always make sure that the people you are working with specialize in equipment recycling as well. If certain elements of your network hardware have value, but other components are antiquated, companies with recycling programs can offer a one-stop shop that provides an additional source of money and ensures piece of mind.

With a slew of recent reports outlining the dangers associated with heavy metals like lead and cadmium that are so prevalent in modern electronics, recycling your spent or broken network hardware is in the best interest of your company and the environment. Network companies that offer joint buy back and recycling programs specialize in identifying worthless equipment and tearing down and disposing of the dangerous subcomponents in those items.

Getting rid of your old network hardware does not have to involve throwing money away and kicking mother nature to the curb. As a responsible business you need to be on the lookout for ways to maximize profits and minimize your impact on the community. Exploring network equipment buy back and recycling programs is a no-brainer decision in the best interest of your organization.

By: Byron Mackelroy, Cisco buy back