What are RAID controllers?

Definition: A RAID controller is a hardware device responsible for managing physical drives in a system and presenting them to the computer as logical units. 

The setting up of RAID 0 and RAID 1 can be done either via software or hardware. Some operating systems allow you to setup RAID in the software itself. A better option is to have a dedicated piece of hardware controlling the RAID functions. A guide to software RAID in Linux.

RAID controller chips are often imbedded in the motherboard. They also come in the form of a PCI expansion cards. 

Hardware RAIDYou need to ensure that the RAID controller card is designed for the type of hard disks you are using. A RAID controller card designed for use with IDE hard disks will not take SCSI hard disks. A controller designed to provide just RAID 0 functions will not allow you to set up a fault tolerant array.

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What is the difference between DDR3, DDR2, DDR, and SDRAM?

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.

 

via-sadop

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Difference Between SATA and IDE Harddisk

From the beginning of the computer era, the storage medium has been constantly evolving. From the floppy disks to the hard disk, their capacity has grown exponentially over the last few decades. But with the ever increasing capacities, new technologies should also be invented to cope up with the need to transfer large quantities of data as quickly as possible. This quest has lead to the transformation from Parallel ATA (also known as IDE) to Serial ATA.

At first sight, you would not notice the difference between a PATA and a SATA disk. The main visual difference appears when you connect them to the motherboard. A PATA disk uses an 80 pin ribbon that is about 3-4 inches wide while the SATA disk uses a 7 pin cable that is less than an inch wide. This allowed for a cleaner cable arrangement inside the case.

The differences between the two don’t end there. SATA disks offer a huge difference in performance when transferring data. Even thhe earliest version of SATA had a maximum transfer rate of 150MB/sec  which is already ahead of the 133MB/sec transfer rate of the fastest PATA disk. Later versions of SATA disks can even achieve up to 300MB/sec. And soon, SATA3 disks would soon be available in the market; offering speeds of up to 600MB/sec. This alone has cemented the role of the SATA as the successor of PATA(IDE) disks in the desktop computer.

Aside from being substantially faster than the older PATA disks, SATA has features that are not found on the former. The Advanced Host Controller Interface utilized in SATA disks allows features like Native Command Queuing (NCQ) that improved the disks speed even more and the ability to connect a disk to an already running computer; this is called hotplug or hotswap technology and it isn’t found on the PATA disks. The hotplug feature of SATA disks also made it practical to allow external SATA disks to be connected just like Flash drives that utilize the USB port, turning the SATA disk into a high capacity portable drive. SATA disk can also be instantly configured into a RAID array if the motherboard supports it. Something that is not possible with PATA drives unless you have a specialized RAID card to handle it.

The shift from parallel to serial has proven to be a very advantageous one. Parallel disks are now beginning to slowly disappear in the market, making way for the faster performance and higher capacities of the SATA disk.

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Features Of Akash Tablet ( Computer )

Features

• Anytime & Anywhere Internet access with Cellular connectivity for only Rs. 98/- per month (in India only)
• Connect via GPRS or WiFi
• GPRS: Embedded modem eliminates the need for external dongles and allows Internet access everywhere
• WiFi: Allows fast Youtube videos at hotspots
• Fast web access even on GPRS networks, across the country using DataWind's patented acceleration technology
• Web, Email, Facebook and much much more!
• High Quallity Video Streaming & HD Quality Video Playback
• Games, Full Office suite, Educational software, Over 150,000 apps!
• Expandable memory to 32GB
• Use any ordinary pen-drive
• Even plug-in a 3G dongle
• And it's a Phone to make/receive voice calls

Specifications

• Android OS 2.3
• Cortex A8, 700 Mhz Processor with HD Video Co Processor
• 256 MB RAM
• Storage: (Internal) 2GB Flash / (External) 2GB to 32GB Supported
• Peripherals: 2 Standard USB Ports (Ver. 2.0)
• Audio Out: 3.5mm jack
• Display and Resolution: 7" Display with 800x480 pixels
• Supported Document Formats: All Version Office Document formats and many more
• High Quality Video Streaming & HD Quality Video Playback
• Input Devices: Resistive Touch Screen
• Connectivity with GPRS & WiFi IEEE 802.11 a/b/g
• Battery: Upto 180 minutes of battery, AC adaptor 200.240 volts

Source : www.akashtablet.com

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BlackBerry launches new PlayBook OS

Ranjan Moses (right), Carrier Product Manager, India, Research in Motion (RIM) and Indranil Aikat, Vice-Presidnet, International Bussinesss and Alliances, Apalya Technologies, during the launch of new BlackBerry PlayBook OS 2.2 in New Delhi on Friday.

Research In Motion (RIM), makers of BlackBerry smartphones, on Friday launched a new operating system (OS) for its PlayBook tablets with additional functionalities, including the ability to run Android-based applications.

The BlackBerry PlayBook OS 2.0 will add advanced messaging features, increased social integration and better browser, among other things, Research In Motion (RIM) Manager, Carrier Product (India), Ranjan Moses told reporters here.

The new OS also supports Android applications like Pool Break Pro.

This will enable developers create applications for Android and make the same applications available to PlayBook users as well.

The new OS is available as a free update for existing users and the new devices will have the new OS in-built.

BlackBerry Playbook is available at an offer price of Rs. 19,990 for the 64 GB model.

In December last year, the Canadian giant had slashed the price of its PlayBook by more than half to Rs. 13,490 for the 16 GB version to cash in on the festive season and burgeoning demand for tablet PCs in India.

RIM, which is known for its BlackBerry series of phones, had introduced PlayBook in June in the Indian market.

According to analysts, sales in the tablet PC segment in India are expected to touch one million units over the next 12 months.

With 3G (high-speed internet services) being rolled out aggressively, the opportunity has only expanded, they said.

Since the launch of Apple’s iPad in the country, the tablet market has been witnessing huge competition, with more and more new contenders launching their devices.

Source : thehindu dtd 24/02/2012

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Union Labour Minister’s Appeal to Trade Unions

Union Labour and Employment Minister Shri Mallikarjun Kharge has appealed to the major central trade Unions to desist from going on countrywide general strike on February 28,2012.The Minister has issued the following appeal here today:

‘ I am pained to learn that all major central trade unions have decided to observe a countrywide general strike on 28th february 2012 when the whole attention of the country is focussed on achieving high economic growth. It may be appreciated that the UPA Government has taken strong measures to contain price rise, as a result of which prices of commodities have decreased significantly in recent months. It is well-known that the interest of the common man is paramount for the UPA Government in all policy decisions, particularly relating to the weaker sections of society, farmers and working class. In pursuance to these avowed objectives the Ministry of Labour and employment has taken many radical steps to improve the lot of working class. Most of the issues relating to labour raised by the central trade unions have already been addressed to a substantial extent. However, i do assure all the central trade unions that i am always open to discussions on any of the issues relating to labour at any time and resolve the same amicably through consultations.

There is no denying the fact that the proposed strike will not only cause colossal economic loss to the country but also bring hardship and inconvenience to the common man.

In view of the above and in the interest of the country I would fervently appeal to all the central trade unions to desist from going on strike on 28th February 2012.

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