Tuesday, May 15, 2012

Overclocking


Overclocking is a term used when the CPU is run at a higher clock rate than prescribed by the manufacturer of the unit. Although it may sound dangerous, the process of overclocking is actually done to speed up the computer’s operation in order to avoid pauses or lags during use. It involves the manipulation of different computer components including BIOS updates and OS drivers.

Advantages of Overclocking

Usually, overclocking is a method done by computer enthusiasts who want to bring their computer’s capacity up a notch without paying for the privilege. For example, one can buy a P1600+ model, overclock it properly and get a speed equal to that of a 1900+. In some cases, overclocking is done to keep the system updated with the requirements without having to spend extra on new hardware. To put it simply, overclocking lets computer users save on money while still getting quality performance in their PC’s.

Disadvantages of Overclocking

Pushing a computer beyond its limit is bound to produce unwanted consequences and for those who are not practiced with overclocking, this could lead to a damaged computer. First of all, owners who overclock their PC’s while still under warranty voids the agreement on the CPU, the motherboard and almost every other component. This is because overclocking affects a wide range of computer hardware either for the better or for the worse.
Putting a CPU through the stress of overclocking also makes it more susceptible to climate changes. In fact, heat generation of an overclocked CPU is found to increase, making it necessary to provide constant cooling to the device. Those who perform the process during winter might also be surprised that the computer would start to malfunction come summer due to the climate change that oveclocking cannot handle. The procedure itself is also temporary, meaning that one cannot expect to overclock each time a new system comes out. At some point, replacing the whole structure would be more ideal than pushing the CPU to its limit.

Overclocking Safety

For those who want to start overclocking, it is important to keep these reminders in mind to avoid damaging the computer.

Gather Information

Overclocking methods vary depending on the computer’s hardware including the motherboard, CPU, RAM, operating system, video card, fan and other devices attached to the PC. The good news is that a lot of forums today have members that provide reliable instructions when it comes to overclocking provided that the aforementioned information is given.

Make Time

Overclocking a CPU takes time and for those who are freshmen in doing this type of work, the process can bring about impatience. However, people should understand that rushing the overclocking process can only lead to failure and might necessitate doing the whole process again. Worse, this could kill the components of the computer, triggering the need to go out and buy a completely new model anyway.

Temperature

As mentioned, an overclocked computer – or even in the process of one – could generate tremendous amounts of heat. Every computer owner should be aware exactly how fast their fan gets rid of computer heat and how long the computer could stand it.

What is RAID?


If you are in the computing business where the data security and availability are crucial at all times, chances are you might have already encountered or even worked with RAID. What is RAID? It is not a living thing but it is has become quite popular and seriously vital in many organizations with multiple users across different locations or even home users accessing multiple pictures at a time. RAID is an acronym for Redundant Array of Independent Disks or sometimes referred to as Redundant Array for Inexpensive Disks. The latter has been coined mostly to illustrate capability for generally improving computing performance and data security by using multiple low-cost disks.
In order to get down to the different efficiency pros and cons of various RAID levels, it is more proper to lay down some clarity to many RAID terminologies. Striping is how data are distributed and written into the various disks that will be set up into array either by byte-level or bit-level. Mirroring is the process by which data written into the other disk is copied onto the other disks simultaneously, creating a redundant replica of the other. Parity on the other hand is use alongside with striping and it is computational procedure that allows the array in determining what information has to be stored into what disk.

Standard Levels

Depending on the priority of the user, there are RAID levels that can be set to give more emphasis on some organizational and business decisions crucial to the operation such as increased computing performance, data security, data availability, and data storage capacity.
RAID 0
This array is mostly used by users who pay more for high performance computing. The adage that says “two heads are better than one” holds true for this set-up. It allows but offers no mirroring or redundancy in the process. The increased performance is made possible with the way data are stored and split into several disks in the array. This works wonders for those on the look out for speeding up the read and write computing functionality.
RAID 1
This set-up offers no striping but allows mirroring in the process. As data are identically written on various disks in the array, there is a very slim chance of losing any data even if the other disks fail in the process. However, performance is a little bit compromised compared to RAID0 array as the write process to a single disk may take a bit more time compared to having them split into several disks.
RAID 2
It is implemented by splitting data at the bit level and spreading it over designated data disks and redundancy disks. The redundant bits are calculated using Hamming codes, a form of error correcting code (ECC).
RAID 3
This array is set-up where striping is on a byte-level and with dedicated parity disk. This means that every file is split up amongst the striped drives equally, byte-by-byte, and this is what makes it exceptional because it allows reading of every byte simultaneously across different drives.
RAID 4
This array set-ups a block-level striping and setting aside a disk for dedicated parity). It is similar to RAID 5 except that it confines all parity data to a single disk which can negatively impact on the speed performance. Nonetheless, the error detection is achieved through dedicated parity which is stored in a separate, single disk unit.
RAID 5
This is set-up allows the bit level striping and distributed parity calculation. This is has been the more popular set-up among the earlier set-ups mentioned as it offers the benefits of RAID3 and RAID4 but without the bottleneck experience caused by a dedicated parity computation in a single disk.
RAID 6
This set-up offers the bit-level striping and double distributed parity calculation. This also means more costly on disk arrays as you would have to make available double quantity of the disks. Across the board it offers reasonable performance but slightly lower than what RAID5 allows. It can expensive, too.

Nested (Hybrid) RAID

There are also arrays that employ the combinations of standard RAID levels by attaching both the standard RAID level numbers before and after a “+”, such as 0+1.
RAID 0+1: This refers to striping of data in mirrored sets. Although this has become more complex for ordinary users, this allows fault tolerance and improved performance.
RAID 1+0: This refers to mirroring of data in a striped set.
RAID 5+1: This refers to the set-up with mirrored striped set and with distributed parity.
The above descriptions and set-up explanations are not all the time applicable to low-end users and may not even be comprehensible to some high-end computing professionals. Nevertheless, knowing that there are possible disk solutions to your computing needs is always a useful piece of information.

Sunday, May 6, 2012

Try Ubuntu Online Before Downloading

Now you can Virtually Try Ubuntu Online Before Downloading


Click on the link below :

http://www.ubuntu.com/tour/en/

MyPhoneExplorer - For Sony Ericsson and Android mobile phones

MyPhoneExplorer is a proprietary freeware desktop application allowing management of Sony Ericsson and Android mobile phones. It is developed in Austria but has been translated into many languages, including English.



Features
MyPhoneExplorer can connect to a Sony Ericsson phone using USB cable, Bluetooth or Infra-red connections. Once connected, address book entries can be synchronized between the phone and MyPhoneExplorer, Microsoft Outlook, Microsoft Outlook Express, Mozilla Thunderbird or Google Mail. Calendar entries can also be synchronized with many systems, including Google Calendar.

As with the PC Suite software which is normally shipped with Sony Ericsson mobiles, files can be dragged and dropped to and from the phone's memory and memory stick. Notably, however, MyPhoneExplorer also allows calls to be managed (i.e. dialled and answered) from within the application, and allows SMS text messages to be saved, read, written, sent, etc. directly from a PC. Moreover, it provides feature of back-up and restore which can back up everything like messages, contacts, calender entries, and files.


Supported phones
MyPhoneExplorer was initially designed for use with Sony Ericsson K700, K750, K800 mobiles, but FJ Software state that it works with all Sony Ericsson phones which are not Symbian-based.
Later versions of the software has support for some Symbian based Sony Erricson phone although some older models are unsupported or require workarounds.

Since version 1.7, MyPhoneExplorer has supported all Android phones running Android 1.6 or higher.

Download Link : MyPhoneExplorer Download Page





Friday, May 4, 2012

View website services tracking you while on a site


Each time you visit a page on the Internet its a good change that a service on that page is tracking you. Below is a listing of some of the common ways a web page will track you when its being viewed. To view how a website is tracking you, block services, and get a better understanding about each tracking services install Ghostery, a free tool that displays all tracking services and gives you additional details about each service. In the picture to the right, is an example of a Ghostery window being displayed for the CNN website, in this example this page normally has eight services tracking the visit, however, six of the services have been disabled.

How a website may track you

Most sites collect analytical data using services such as Google Analytics to help the owner of a website understand how their web page is being used.

Sites with share buttons from Facebook, Google+, and other social networks will also track each visitor that views the share button or a social network plugin. Users logged into these social services can be tracked and also share the pages through the services.

Many advertisers such as Google (DoubleClick) will track where their advertisement banners are displayed.

Hundreds of other services that monitor traffic, brands, patterns, mobile, etc. for research and advertisers.


Click on the above link to visit and download Ghostery from its website.

Tuesday, May 1, 2012

How to setup multimedia on CentOS-5 and RHEL-5


Step 1: Add RPMforge repository access for your CentOS system. (Required for the majority of multimedia packages.)
You can read the installation instructions at Installing RPMForge.
Step 2: Install the multimedia applications.
The following steps will use yum to install all the packages needed to have full multimedia support. Note there will be a lot of dependencies.
yum install compat-libstdc++-33 libdvdcss libdvdread libdvdplay libdvdnav lsdvd libquicktime
yum install flash-plugin mplayerplug-in mplayer mplayer-gui gstreamer-ffmpeg gstreamer-plugins-bad gstreamer-plugins-ugly
Step 3: Install the w32Codecs. (Required for xvid and other proprietary formats.)
wget www1.mplayerhq.hu/MPlayer/releases/codecs/mplayer-codecs-20061022-1.i386.rpm
rpm -ivh mplayer-codecs-20061022-1.i386.rpm
wget www1.mplayerhq.hu/MPlayer/releases/codecs/mplayer-codecs-extra-20061022-1.i386.rpm
rpm -ivh mplayer-codecs-extra-20061022-1.i386.rpm
You should now have full multimedia and video support for most popular formats.
If you happen to have problems with playing video's (eg. the player crashes or you have no image), try to disable System > Preferences > Desktop Effects (Compiz) and see if that fixes your problems.

CCNA Certification Exam Training: Telnet & VTY Line Passwords


Telnet is a simple yet powerful program that allows you to connect to a remote Cisco router or switch, and then configure it as though you were right at the console. Telnet is also one of those features that seems so very simple, until you get asked a half dozen questions about it on your CCNA exams.

One common belief about Telnet: Telnet runs at layer 7 of the OSI model, not layer 3. It’s easy to think that Telnet runs at Layer 3 of the OSI model, the Network layer. After all, you’re entering an IP address when you telnet in to a router or switch, and you may be on another router when you do it.

None of that matters. Layer 3 is strictly routing. Like other features that require input from the end user, especially authentication, Telnet runs at the Application layer of the OSI model.

Speaking of authentication…
Cisco routers can run quite a few passwords. We can set an enable password, an enable secret, an enable secret and enable password, a password for PPP connections, and even a console password.

All of those are optional, but the telnet password is not. Makes sense – you wouldn’t want just anyone telnetting into your router, would you?

We'll see how to set that password and note other vital Telnet details right after this brief and important message!

Now back to Telnet...
If you have no password set on the VTY lines of your router, no one can telnet in. If they try, they’ll see this message:

R1#telnet 3.3.3.3
Trying 3.3.3.3 ... Open
Password required, but none set
[Connection to 3.3.3.3 closed by foreign host]

To allow telnet access into a Cisco router, configure the VTY lines with a password and the login command:

R3#conf t
Enter configuration commands, one per line. End with CNTL/Z.
R3(config)#line vty 0 4
R3(config-line)#login
% Login disabled on line 2, until 'password' is set
% Login disabled on line 3, until 'password' is set
% Login disabled on line 4, until 'password' is set
% Login disabled on line 5, until 'password' is set
% Login disabled on line 6, until 'password' is set
R3(config-line)#password cisco

Note the messages you get after enabling login. These messages simply indicate that the login won’t work until a password is set. The order with which you use the login and password commands don’t matter just make sure you use them both.

We’re not quite done, though. The remote user can now telnet in, but by default, that user will be placed into user exec mode. If the user is to be allowed to enter privileged exec mode during a telnet session, an enable password or enable secret must be set.

R1#telnet 3.3.3.3
Trying 3.3.3.3 ... Open
User Access Verification
Password: <we entered the password here >
R3>enable
% No password set
R3>

The user is stuck in user exec until you set a local enable password. Doing so will allow the user to use that password to enter privileged exec mode.

R3#conf t
R3(config)#enable password ccna
R3(config)#^Z
R1#telnet 3.3.3.3
Trying 3.3.3.3 ... Open
User Access Verification
Password: < user entered cisco here>
R3>enable
Password: < user entered ccna here >
R3#

The user is now in privileged exec mode. There’s also another method to use so the user is placed directly into privileged exec mode when telnetting in, avoiding the enable password prompt. Use the command privilege level 15 on the VTY lines to do so.

R3#conf t
R3(config)#line vty 0 4
R3(config-line)#privilege level 15
R1#telnet 3.3.3.3
Trying 3.3.3.3 ... Open
User Access Verification
Password: < user entered VTY line password here >
R3#

Note that the user went straight to privileged exec mode!