Sunday, June 27, 2010

Difference between Core 2 Duo and Core Duo



Dual core is simply a generic term referring to any processor package with two physical CPUs in one. The Pentium D, Core Duo, Core 2 Duo and Athlon X2 are all current CPUs that have dual cores in one package.

The Pentium D is simply two Pentium 4 Prescott cpus inefficiently paired together and ran as dual core.

The Core Duo is Intel's first generation dual core processor based upon the Pentium M (a Pentium III-4 hybrid) made mostly for laptops (though a few motherboard manufacturers have released desktop boards supporting the Core Duo CPU), and is much more efficiently than Pentium D.

The Core 2 Duo is Intel's second generation (hence, Core 2) processor made for desktops and laptops designed from the ground up to be fast while not consuming nearly as much power as previous CPUs.


Note - Intel has dropped the Pentium name in favor of the Core architecture as Intel is restructuring and refocusing it's efforts to become number one again (and are doing a fine job, might I add).

The AMD Athlon X2 CPUs have two revisions, the first one is essentially very similiar to the Pentium Ds in that they are simply two Athlon 64 chips fused together, making power requirements quite steep (around 89 watts). The second revision is made more efficiently, like the Core Duos, with much less power consumption (around 65 watts).


There are, of course, other differences, but that is the gist of dual cores as it relates to Intel and AMD.

Friday, June 25, 2010

Difference between DVD-R, DVD+R, DVD+RW and DVD-RW




There’s DVD+R, DVD+RW, DVD-R, DVD-RW, and even DVD-ROM! So what’s the difference between all of these different names, aren’t all DVDs the same? Well, it’s not quite that simple.

Let’s first start with the most obvious difference: some have R and some have RW. The “R” stands for recordable, while the “W” stands for rewriteable.

The main difference between DVD-R and DVD-RW, or DVD+R and DVD+RW is that the R disc formats can only be written to once, and then it is only readable and can’t be erased for the rest of its digital life. While RW discs are can be written to and erased many times, they are both readable and writeable.

“R” discs are perfect if they are only needed to be written to once, such as giving some files to a friend or transferring them between PCs. “RW” discs have their strength in the ability to be used many times over, which is great for routine system backups, etc. And naturally, the RW discs are slightly more expensive than the R discs, but you’ll have to decide if the trade offs are worth the money.

Now, onto the difference between DVD-R and DVD+R. As I just described above, DVD-R & DVD-RW are sister discs, the difference being one is writeable once, while the other is writeable multiple times. The same thing is true for DVD+R & DVD+RW. So the question is, what’s the difference between the plus and minus?

In order to explain this we must take a trip back in time. When DVDs were first being developed, there was no industry standard. Multiple companies were competing to develop what they hoped would be the dominant form of the future.

The DVD-R DVD+R difference can easily be summarized by the following:
  • The DVD-R/RW standard was developed by Pioneer, and is used primarily by Apple and Pioneer. These “minus“ discs can only be written to in one layer on the discs surface. In addition, this format is supported by the DVD forum, but is in no way an industry standard. DVD-R/RW discs are cheaper than the “plus” format.

  • The DVD+R/RW format is supported by Philips, Dell, Sony, HP, and Microsoft. These discs can be written to in multiple layers, giving them slightly better and more disc storage than the “minus“ format. Because of this additional capacity, they are slightly more expensive than “minus“ discs.
A couple final things to clear up is the difference between DVD-ROM and DVD+RW, or the other DVD formats I mentioned above. The DVD-ROM drive can only read DVDs, while the other DVD drives can read and write data to DVDs.

And naturally the DVD+RW CD+RW difference can be explained by the “DVD” or “CD” prefix. DVDs, on average, can store up to 4.7 GB of data, while a CD can only store about 700 MB of data, or about 15% of a DVD’s capacity. While CDs are slightly cheaper, in my opinion, the benefits of DVDs are much greater.

Friday, June 18, 2010

Differences between an Ethernet hub or switch and a broadband router




Most broadband routers (“routers” for short) are a combination Ethernet switch (or hub) and Network Address Translator (NAT; see below). They usually include a Dynamic Host Configuration Protocol (DHCP) server, Domain Name Service (DNS) proxy server (see below), and a hardware firewall to protect the Local Area Network (LAN) from malicious intrusion from the Internet.

All routers have a Wide Area Network (WAN) Port. This port connects to the to a DSL or cable MODEM for broadband service (e.g., the Internet) and is usually a 10 MHz 10BASET Ethernet port. A 10 MHz WAN port is sufficient for cable and DSL MODEMs as these devices transfer data at rate that is a fraction of 10 MHz. I have seen no broadband routers with a USB WAN port to connect to a USB cable or DSL MODEM.

Many recent broadband routers are combination routers/Ethernet switch (or hub) that have multiple Ethernet ports to connect more than one PC to form a LAN. These ports allow the PCs to share the WAN port/broadband Internet connection and perform LAN functions, such as Windows file and printer sharing. The LAN ports are usually 100 MHz 100 BASE-TX Ethernet.

Some routers have a single WAN port and a single LAN port and are designed to connect to an existing LAN hub or switch to a WAN.

Ethernet switches and hubs can be connected to router with multiple PC ports to expand a LAN. Depending on the capabilities (kinds of available ports) of the router and the switches or hubs, the connection between the router and switches/hubs may require straight-thru or crossover cables

In short, a hub glues together an Ethernet network segment, a switch can connect multiple Ethernet segments, and a router can do those functions plus route TCP/IP packets between multiple PCs on LAN and a WAN, and much more.

Friday, June 11, 2010

Difference between an Ethernet hub and switch.



Although hubs and switches both glue the PCs in a network together, a switch is more expensive and a network built with switches is generally considered faster than one built with hubs


When a hub receives a packet (chunk) of data (a frame in Ethernet lingo) at one of its ports from a PC on the network, it transmits (repeats) the packet to all of its ports and, thus, to all of the other PCs on the network. If two or more PCs on the network try to send packets at the same time a collision is said to occur. When that happens all of the PCs have to go though a routine to resolve the conflict. The process is prescribed in the Ethernet Carrier Sense Multiple Access with Collision Detection (CSMA/CD) protocol. Each Ethernet Adapter has both a receiver and a transmitter. If the adapters didn't have to listen with their receivers for collisions they would be able to send data at the same time they are receiving it (full duplex). Because they have to operate at half duplex (data flows one way at a time) and a hub retransmits data from one PC to all of the PCs, the maximum bandwidth is 100 Mhz and that bandwidth is shared by all of the PC's connected to the hub. The result is when a person using a computer on a hub downloads a large file or group of files from another computer the network becomes congested. In a 10 Mhz 10Base-T network the affect is to slow the network to nearly a crawl. The affect on a small, 100 Mbps (million bits per scond), 5-port network is not as significant.



Two computers can be connected directly together in an Ethernet with a crossover cable. A crossover cable doesn't have a collision problem. It hardwires the Ethernet transmitter on one computer to the receiver on the other. Most 100BASE-TX Ethernet Adapters can detect when listening for collisions is not required with a process known as auto-negotiation and will operate in a full duplex mode when it is permitted. The result is a crossover cable doesn't have delays caused by collisions, data can be sent in both directions simultaneously, the maximum available bandwidth is 200 Mbps, 100 Mbps each way, and there are no other PC's with which the bandwidth must be shared.

An Ethernet switch automatically divides the network into multiple segments, acts as a high-speed, selective bridge between the segments, and supports simultaneous connections of multiple pairs of computers which don't compete with other pairs of computers for network bandwidth. It accomplishes this by maintaining a table of each destination address and its port. When the switch receives a packet, it reads the destination address from the header information in the packet, establishes a temporary connection between the source and destination ports, sends the packet on its way, and then terminates the connection.

Picture a switch as making multiple temporary crossover cable connections between pairs of computers (the cables are actually straight-thru cables; the crossover function is done inside the switch). High-speed electronics in the switch automatically connect the end of one cable (source port) from a sending computer to the end of another cable (destination port) going to the receiving computer on a per packet basis. Multiple connections like this can occur simultaneously. It's as simple as that. And like a crossover cable between two PCs, PC's on an Ethernet switch do not share the transmission media, do not experience collisions or have to listen for them, can operate in a full-duplex mode, have bandwidth as high as 200 Mbps, 100 Mbps each way, and do not share this bandwidth with other PCs on the switch. In short, a switch is "more better."

Friday, June 4, 2010

How to Install IIS on Windows Vista, Windows XP and Windows 2000



Follow these steps to install IIS on Windows Vista:
Internet Information Services (IIS)

1.Open the Control Panel from the Start menu
2.Double-click Programs and Features
3.Click "Turn Windows features on or off" (a link to the left)
4.Select the check box for Internet Information Services (IIS), and click OK
After you have installed IIS, make sure you install all patches for bugs and security problems. (Run Windows Update).


Follow these steps to install IIS on Windows XP and Windows 2000:

1.On the Start menu, click Settings and select Control Panel
2.Double-click Add or Remove Programs
3.Click Add/Remove Windows Components
4.Click Internet Information Services (IIS)
5.Click Details
6.Select the check box for World Wide Web Service, and click OK
7.In Windows Component selection, click Next to install IIS
After you have installed IIS, make sure you install all patches for bugs and security problems. (Run Windows Update).

Test Your Web
After you have installed IIS, follow these steps:

1.Look for a new folder called Inetpub on your hard drive
2.Open the Inetpub folder, and find a folder named wwwroot
3.Create a new folder, like "MyWeb", under wwwroot
4.Write some ASP code and save the file as "test1.asp" in the new folder
5.Make sure your Web server is running (see below)
6.Open your browser and type "http://localhost/MyWeb/test1.asp", to view your first web page
Note: Look for the IIS (or PWS) symbol in your start menu or task bar. The program has functions for starting and stopping the web server, disable and enable ASP, and much more.