Good lord. Since you've obviously never heard of google, I'll try to explain some of this.
Firewire (aka IEE1394): typically an external connection. Like USB. It's a serial signal that can go up to 400mbps. Firewire 2/2.0 can go up to 800mbps. Apple popularized this sort of connection with the iPod and iMac. Sony used it as well too. It's still a very popular connection for high end video cameras. Apple has since moved to USB for most of their devices.
USB 1.0/1.1 (aka, Universal Serial Bus): external connection. Serial signal. Up to 12mbps. You can daisy chain up to 168 devices on a single port. Though, no one does this. Every computer built after say... 1996 has this connection.
USB 2.0: up to 480mbps, though i doubt 480mbps has ever been achieved. Still serial. Backwards compatible with USB 1.1. Popularized around 2000/2001.
SATA: (Serial Advanced Technology Attachment) serial component interface for hard drives and CDROM drives. First ATA standard allowed for 150mbps throughput. SATA2 allows for 300mbps. SATA is much faster than Ultra ATA 133. Also, you don't have to play the slave/master game with SATA.
DMA/IDE/ATA 33/66/100/133/166. These refer to IDE drives such as hard drives and CD ROM drives. IDE stands for Integrated Drive Electronics. ATA acronym is the same as SATA's. DMA/IDE/ATA are parallel signals. Many computers still use IDE drives. Almost all motherboards still have connections for IDE drives. There are 4 speeds currently in use, 33mbps (popular with CD/DVD Roms), 66mbps (hard drives), 100mbps (hard drives again), and 133mbps which was the last real supported speed. Ultra ATA 166 specs did come out, but SATA came out at the same time. SATA was considered to be better than Ultra ATA 166 so it never really caught on. Most CD ROM drives sill use ATA33 speeds. Since CD ROMS are slow and cannot (right now) burn faster than 33mbps, ATA33 is what they use. However, DVD burners can burn as fast as 22MB/s or 176mbits/second many are now using SATA interfaces.
UDMA: same as ultra DMA or ATA133.
Bluetooth: wireless protocol for devices. Transmits up to 1mbps. Range is 32 feet and can transmit data/voice. Operates on 2.4Ghz. Very similar to 802.11b spec- just slower. Typically used in cell phones and other wireless devices. The most popular bluetooth product is the hands free ear piece/mic commonly seen in use with cell phones.
WiFi: wireless data signal. there are many standards now for WiFi. the first was 802.11b. 802.11b can transmit up to 11mbps on a 2.4Ghz frequency. there's 802.11a which can transmit up to 54mbps on a 5Ghz frequency. Then there's 802.11g which operates on 2.4Ghz at 54mbps.
There are even more developing standards (including WiMAX)... however 802.11b and g are the most popular right now.
Standard network adapters: 10mbits/100mbits/1000mbits (gigabit). No need for comparison. The most popular is 100mbits with 1000mbit quickly gaining popluarity.
ISA & EISA (Industry Standard Architecture). This was one of the first peripheral component connects in PC's. There were 3 flavors, 8bit, 16bit, and 32bit. 8bit ran at 4Mhz and 16bit/32bit ran at 8mhz. ISA was very popular in it's day. It accomodated everything from modems and video cards to controller cards for floppies. Before ISA faded away EISA was released. It supported 32bit cards and had a higher throughput. EISA was popular in 486's and even some original Pentium boards. EISA stuck around in motherboards until around the Pentium MMX/AMD K6! ISA cards were backwards compatible with EISA slots- though not many cards existed that could take advantage of EISA's larger bus. All flavors of ISA are now phased out and cannot be found in any new motherboard.
MCA (Microchannel Architecture). This architecture was
way ahead of it's time. Originally developed and introduced by IBM in 1987 it had similar peformance capabilities as PCI! However, it never really caught on in the desktop market. Lots of people say it never caught on because it wasn't backwards compatible with ISA. However, a little known fact is that IBM wanted to license the architecture to motherboard manufacturers and PC makers. They balked at the licensing costs and quickly developed their own comparible standard, EISA. Additionally, IBM was trying to force the technology down eveyone's throat. Suffice to say, MCA never made it into desktop computers.
VLB (VESA Local Bus). In between ISA and PCI came VLB. VLB was similar to ISA, but was 32bits. Clock speed was determined by the CPU installed. Speeds ranged from 25Mhz to 50Mhz Though VLB could be used for almost anything, it was primarily used for video cards. 3D games were in their infancy when VLB was introduced. (Examples include Doom and Wolfenstein 3D). Though the video cards were not "3D accelerated" they supported higher resolutions and 32bit color- both of which required the extra bandwidth of VLB. VLB never made it's way into Pentium motherboards. It died along with the 486.
PCI (peripheral component interconnect): 33mhz with a maximum throughput of 133mbits/second. 32bits. Parallel signal. Still very popular. Invented in 1991 by intel. Effectively replaced ISA (Industry Standard Architecture, which was 16bits at 8mhz). PCI has proven to be one the most reliable and popular connects in PC history. In 10 years it still remains the standard for basic components. It will take a long time to phase out PCI. Probably another 2-3 years.
PCI-X (same, with an X). Still parallel. Originally developed for servers PCI-X is 64bits. Was supposed to replace PCI 33, but never really caught on in desktop market. 4 speeds: PCI-X 66/133/266/533. Backwards compatible with PCI 33. PCI-X is almost always available in servers. Currently very popular in enterprise market. The most common uses of PCI-X are SCSI/RAID controllers and other high end network switches/hubs/routers, etc. There are a couple new PCI-X speeds in development as I write this posting. Their purpose: to compete with PCI-Express.
AGP: Accelerated Graphics Port. Introduced in 1996. Designed specifically with graphics cards in mind. At the time, video cards were pushing the throughput limit of PCI- so AGP had to be invented. There are 4 speeds, 1x, 2x, 4x, and 8x. Between AGP 4x and AGP 8x, there was AGP Pro, which was supposed to do accommodate future versions of AGP. But, Intel developed a new specification called the AGP 8x. AGP Pro slots will accept AGP 8x cards, but will deliver only AGP 4x performance. AGP 8x is still very popular. AGP has proven to be one of the most important bus advances for video cards. It was the first bus ever created with video specifically in mind. Most video cards can still be bought in AGP format with the exception of very high end video cards. AGP probably won't be around much longer... I give it another year or so.
PCI-Express. (same, with an express). Serial interface. Very quickly gaining popularity. PCI-Express was originally designed with video cards in mind. However, there are 5 PCI-Express speeds. 1x, 2x, 4x, 8x, and 16x. 2x, 4x, and 16x are commonly seen on new motherboards. I don't think any mobo has a specifically designed 8x slot... however 16x can go down to 8x. Technically, all cards in ascending order are supposed to compatible with all slots. In other words, a 16x video card can fit in a 2x and 4x slot. However, the throughput is drastically reduced. PCI-Express will probably replace PCI eventually. The jury is still out on if it will replace PCI-X. At this point, it looks unlikely that it will replace PCI-X anytime soon.
----------------------------------------------------------------------------------------------------------------------------
OK, now on to the last questions
What's the difference between using an external HD or a Memory Key and a normal HD?
Memory keys (aka, USB jump drives) use flash memory chips to store information. They connect via USB ports. External hard drives use a magnetic head that reads/writes data to rotating discs. The magnetic signal re-arranges bits of data on the discs. Difference between an internal and external hard drive is typically the interface. Internal hard drives use either IDE or SATA interfaces which are much faster than USB. External hard drives use USB or firewire ports- these are slower. However, external SATA ports are gaining popularity. Soon, there won't be a difference in speed between internal and external hard drives. Which is good!
What's the difference between using an external USB 2.0 HD and the Firewire version?
Not a whole lot. The biggest difference is USB is serial and firewire is parallel. Both have similar speeds. USB typically eats more processor power than firewire- which can decrease performance. I prefer to use firewire for external hard drives. Benchmarks have shown that it's usually slightly faster.
What's the speed difference in connecting 2 computers through standard network cards, wi-fi, bluetooth, or USB lan?
Biggest difference is speed. The fastest way to connect two computers is almost always going to be via 1gbit ethernet, 100mbit ethernet, or fiber. The slowest of the 4 would be bluetooth with USB and wifi in between. The most common type of LAN connection is 100mbps ethernet. However, wireless is quickly becoming popular. The only downside to wireless is security. To date, all wireless security protections ever invented have been cracked in some way or another. Wireless connections are ideal for a home network, small office, and in some cases an enterprise setting. It all depends on how sensitive the data being transfered is and what's accessable on the network. Many nuclear weapons research labs use wireless networks, including Sandia National Labs and Los Alamos National Labs (where I work). However, the networks are completely independent of other networks containing secret information.
Hope this helps.
-mpjesse
EDIT: thanks to RichPLS and fishman for their help on this!
Facebook
Twitter
Instagram