USB

USB 2.0 - Hi-Speed USB - FAQ


What is USB 2.0?
USB 2.0 is a complete overhaul to the Universal Serial Bus input/output bus protocol which allows much higher speeds than the older USB 1.1 standard did.

USB 1.1 allowed a maximum transfer rate of 12Mbits/second. That rate is now called 'USB.' Though some manufacturers label their products Full-Speed USB. Note that this seems a bit deceptive. Its easy to mistake Full-Speed for Hi-Speed.

As an aside, USB mice and keyboards need only 1.5Mbits/s to function. That performance level is also named 'USB' by the USB Promoter Group.

To sum it up, USB 2.0 specification incorporates three speeds: Hi-Speed, Full-Speed and Low-Speed. You as a consumer don't need to figure out all the jargons. Just keep in mind that only 'Hi-Speed USB' and 'USB' host and devices exist.

How do I know if my PC has USB 2.0?
You can identify whether your PC has Hi-Speed or not relatively easy. Open Device Manager and expand the Universal Serial Bus section. There should be an "Enhanced" USB host controller present.

Windows 98 systems may use a different name, because Hi-Speed USB drivers in these operating systems are not provided directly from Microsoft (Windows ME, 2000 and XP get their drivers through Windows Update).

These drivers are provided by the manufacturer, and may carry the maker's name (i.e. ADS, Belkin, IOGear, Siig, etc.). There should also be two standard version USB host controllers present as well. They are embedded in the USB chip which routes the differing USB speeds accordingly without user intervention.

There are currently 6 manufacturers of the Hi-Speed USB host silicon themselves:

• ALi (Acer Labs)
  

• Intel
  

• NEC
  

• SiS
  

• VIA
  

• nVidia (shows as "Standard" controller
  

Any other brand name that appears in Device Manager would likely be an add-in Hi-Speed USB PCI card. The makers above do not make add-in cards, but they do make the chips that are used in them.

How do troubleshoot "unknown device" error listed in Device Manager?

• The USB device or the USB adapter requires its own power source. If your USB device or adapter came with an AC power "brick", try connecting it.
  

• Here's a likely one - the front USB ports on your PC case may be misconnected. I've seen them that way from the factory. It's a good idea to check the connections against specifications. The standard order of connection is Red, White, Green, and Black. No more than 4 wires per USB bank are needed.
  

• Defective device. Do not assume that all PC components work correctly out of the box. I've seen many new USB devices that do not work. If you can, try the device on another PC.
  

• All drivers are not installed. Some devices will require installing the driver package before plugging in the device. Some devices will also require basic USB files from the Windows CD before the unit will function. The general rule is to always follow installation directions precisely and to have the Windows CD ready.
  

How fast is USB 2.0?
USB 2.0 has a raw data rate at 480Mbps, and it is rated 40 times faster than its predecessor interface, USB 1.1, which tops at 12Mbps. Originally, USB 2.0 was intended to go only as fast as 240Mbps.

How will consumers benefit from USB 2.0?
With speed 40 times more than that of USB 1.1, USB 2.0 broaden the range of external peripherals that can be used on a computer. Even with multiple high-speed peripherals connected to a USB 2.0 bus, the system will less likely to hit the bandwidth bottleneck. The new specification also inherits the current USB's Plug and Play and hot-swapping capability as well as providing backward compatibility for USB 1.1 hardware, allowing existing user base to upgrade seamlessly.

Do USB 2.0 & USB 1.1 hardware work interchangeably?
You may have heard that USB 2.0 is "backward-compatible" with USB 1.0/1.1 (Full-Speed USB). While that's true, USB 1.1 is also forward-compatible with USB 2.0. Whenever a system has USB 2.0 ports, you'll find the "Enhanced" USB controller in Device Manager, but you will also find two other USB controllers. These two to maintain backward compatibility to USB 1.1 devices. Each USB 2.0 host actually has 3 chips onboard. The USB controller routes signals to the correct controller chip depending on how a device is recognized. Where a device is physically plugged in has no bearing on how it is routed. All ports on a USB 2.0 motherboard can host any USB devices at all as long as the system and devices are healthy.

The vast majority of USB 2.0 devices will work on older PCs and Macs. None should flat-out fail unless there are other issues with the system. Hi-Speed USB devices will revert to Full-Speed operation when connected this way. Understand that Hi-Speed is at least ten times faster than Full-Speed in actual operation, so the speed difference is quite noticeable - unless you have never experienced Hi-Speed, of course.

When it comes to USB hub compatibility between USB 2.0 and USB 1.1, here some facts:

• A powered hub is always preferable to unpowered.
  

• USB hub ports are not as capable or flexible as real PC ports so it's best not to expect the world of them.
  

• USB 1.1 (obsolete) hubs will work fine on USB 2.0 ports, but they cannot utilize USB 2.0 capabilities. They will default to slower speeds.
  

• Hi-Speed and Full/Low-Speed USB devices can coexist nicely on USB 2.0 hubs. Connecting such a hub to a USB 2.0 port is recommended.
  

• USB 2.0 hubs can be used on older USB 1.1 computers.
  

• Although it is said that you can "cascade" up to 4 hubs, problems may start to arise after two hubs, it's best to minimize hub usage if possible.
  

• Many USB devices don't work well on hubs. Cameras, scanners and especially USB drives are known to have problems with hub connectivity.
  

• Remember that "active USB extensions" are really just one-port hubs.
  

Will USB 2.0 replace USB 1.1?
Not entirely, because many products such as generic keyboards, mice, joysticks and audio speakers do not require the faster speed of the new USB 2.0 technologies. Only bandwidth-hungry devices, such as web cams and high-capacity storage systems, will need all the speed. However, next-generation systems will come with USB 2 ports rather than USB 1.1.

How do I distinguish between a USB 2.0 and a USB 1.1 devices? New logos designed by the USB Promoter Group allow consumers to easily identify the new USB 2.0 products. The new colorful logo for USB 2.0 is labeled USB Hi-Speed, and the new logo for USB 1.1 is labeled with USB Basic Speed. However, most people won't miss it as manufacturers often label USB 2.0 READY Or 40 times faster than USB 1.1, on the boxes.

Will USB 1.1 devices run any faster on a USB 2.0 bus?
No. However, the new USB 2.0 archiclecture allows more high-speed USB 1.1 devices, such as web cams, audio devices, to share the bandwidth. Developers need to follow USB 2.0 spec in order to design higher speed peripherals that can take advantage of the extra bandwidth. USB 1.1 devices still operate at 12Mbps at full-speed and 1.5Mbps at low-speed on a USB 2.0 bus. Even though USB 1.1 devices won't run any faster, they can work alongside of USB 2.0 devices on the same bus.

What are USB Hi-Speed and USB Basic Speed logos?
These logos are part of USB Promoter Group's branding program that ensures the quality of USB products. The USB 2.0 certified products would display a blue, white and red logo, bearing the words Certified and Hi-Speed. The classic USB 1.1 certified products would display a black and white logo with the words USB and Certified.

Under a license from USB-IF, products must pass the compliance tests before manufacturers can use one of the two trademarked logos. The Promoter Group will take legal actions on manufacturers that label either logo on their products, which have not passed the tests.

What happen if a USB 2.0 devices are plugged into a USB 1.1 systems?
The entire bus under the USB 1.1 root hub will slow to 12Mbps. The operating system will probably notify the user about the sub-optimal configuration and recommend for a better course of action.

If several USB 1.1 hubs are connected to a USB 2.0 bus, then each of the USB 1.1 hubs will get a full 12Mbps bandwidth.

What is the max? Length of a USB 2.0 cable?
5m. however, if you cascade 5 hubs with 5m USB cables, this will allow you to connect a device 30m away.

What do I need to use a USB 2.0 device?
The requirement is similar to that of USB 1.1, but all components will have to be USB 2.0 compliant. A successful USB 2.0 connection requires a USB 2.0 host controller card, a USB 2.0 driver and a USB 2.0 peripheral.

How much will it cost to upgrade to USB 2.0?
Around $80 to $150. Currently, Orange Micro., Adaptec and IO Gear are shipping USB 2.0 PCI cards, some of which even have FireWire ports. Interestingly, almost all USB 2.0 PCI cards include an internal port, which is probably for connecting internal USB 2.0 IDE enclosure or USB 2.0 front panel.

Will USB 2.0 arrive on mobile computers?
Yes, but not in integrated solution on laptops. You will need a USB 2.0 Card Bus card. Orange Micro. is shipping USB 2.0 compliant 4-port Card Bus card. Eventually, notebook vendors will adapt to USB 2.0 technology, and we will see USB 2.0 ports on laptops. This transition won't happen until 2002 at the earliest.

Which operating systems support USB 2.0?
Microsoft has released the official USB 2.0 driver for Windows XP and Windows 2000. The version is 5.1.2600. The software is available on-line at Windows Update website. (If you don't have a USB 2.0 card installed in your system, Windows Update won't list the USB 2.0 driver as an update.)

The software company is still considering USB 2.0 support for Windows ME, but it already has decided not to bring USB 2.0 to Windows 98 and Windows 98 SE. If you have Windows 98, you will have to rely on 3rd party USB 2.0 support from USB card manufacturer.

Do USB 1.1 cables work with USB 2.0 devices?
Ideally, yes. USB 2.0 architecture uses the same cables and connectors as USB 1.1 compliant products. Unfortunately, only 3 out of 11 cables on the market are certified as USB 1.1 compliant. You may run into the cables that cause problems connecting high-speed peripherals. To avoid negative user experience, most vendors include USB 2.0 compliant cables with their USB 2 PCI cards and peripherals.

Speed up the Start Menu Tips

If you are still working with old or slow computer but don't worry, you can give surprise to your friends with some changing in windows registry. Edit your computer registry keys to speed up your computer start menu, because the default speed of start menu is slow. After these changes your computer start menu will response like latest computer.

Follow the given steps to change the speed of Start Menu.

• First click on Start button then type Regedit in Run option.
  

• In Registry Editor panel go to the path:
  

HKEY_CURRENT_USER \ Control Panel \ Desktop \ MenuShowDelay

• By default the value "MenuShowDelay=400", but you can set value between 0 to 400. Now put the value "MenuShowDelay"=0 to speed up.
  

• Now close the registry editor and restart your computer after any changes to go into effect.

WiMAX

WiMAX Wireless Broadband Info

WiMAX stands for World Interoperability for Microwave Access that enables the actual broadband wireless network with high speed. WiMAX operate same like WiFi but WiFi operate with some limitation like it is base band technology and cover only 100 feet radius with slow speed. WiMAX covers a radius of 50 Km and work with the speed of 70 Mbps. WiMAX is the replacement of the wired broadband. In wired broadband connection, we can transmit data with 512 Kbps to 10 Mbps speed and more, for example DSL broadband and cable broadband. In future all new desktop and notebook computers will be incorporated with WiMAX technology. With this technology you will be connected to the internet even you are driving your car with the speed of 120 Km.

Objective of WiMAX

• Superior Performance

• Flexibility
  

• Advanced IP-Based Architecture
  

• Attractive Economics

IEEE 802.16 Specifications

• Range 30 mile radius from the base station for LOS (line-of-sight).
  

• Range 4-6 miles radius from the base station for NLOS (Non-line-of-sight)
  

• Maximum data speed supported as 70 Mbps.
  

• Licensed frequency band: 2- 11 GHz
  

• Un-licensed frequency band: 10- 66 GHz
  

• Line of sight is not needed between user and the base station unless very high date rates are required at the user premises.
  

RAID

RAID level 0

1. Actually not use RAID redundancy does not improve in performance.
2. Data distributed on the entire disk array, is the advantage of using a large capacity disk.
3. RAID - 0 become a model of the data strip on the disk with a data management system specific to the data stored on considered a logical disk.
4. Mechanism for the transfer of data in one sector at a time so that only good for handling large data transfers.
   

RAID level 1

1. Redundancy obtained by duplicate all the data on the disk mirror.
2. As with RAID - 0, RAID - 1 stripping also use the technology.
3. The difference is in level 1 each strip mapped to the logic of the two disks that are logically separate so that each disk arrays will have a mirror disk that contains the same data.
4. RAID - 1 expensive.
5. RAID - 1 increase in performance approximately doubled compared to RAID - 0 in the operation read, but not to write operations significantly increased.
6. Matches are used to handle data that is often experienced failure in the process of reading.
7. RAID - 1 still working on sector-sector.
8. Benefits of RAID - 1:

• Request reading can be served by one of the disk because there are two disks contain the same data, depending on access to the fastest time.
• Demand for storage or writing is done on 2 disks in pararel.
• There are beack-up data, namely the disk in the mirror.
  

RAID level 2

1. RAID - 2 using the technique pararel access to all the disk. - All participating disk and executing every request so that there are mechanisms for synchronization and disk rotation head.
2. Technology used in the stripping this level, only strip small size, often in word or byte size.
3. Use a system error correction bits parity with the Hamming code.
   

RAID level 3

1. Organized similar with RAID - 2.
2. The difference in RAID - 3 requires only a single disk redudant, does not depend on the number of arrays disk.
3. Computing parity bit for each word and write data on disk pritas special.
4. When the drive failure occurs, the data re-arranged the rest of the data is still good and from information paritasnya.
5. Using pararel access to the data distributed in the form of small strip-strip.
6. Performing high-yield transfer, but can only executing a request.
7. I / O, so only if used in high data transaction environment decline in performance.
   

RAID level 4

1. Using techniques that independent access to every request so that disknya read or write served in pararel.
2. RAID is suitable to deal with the culture system data transfer rates.
3. No need synchronization because each disk operate independently.
4. Stripping the data in a large size.
5. Strip parity bits-per-bit is calculated to strip all the related data on each disk.
6. Parity stored on disk for parity.
7. When the writing operation, array management software not only to update the data but also related to parity.
8. Benefits of parity with the disk that has made special security data more secure, but with a separate disk parity will slow performance.
   

RAID level 5

1. Having a similarity with RAID - 4 in the organization.
2. The difference is strip-strip parity distributed across the entire disk.
3. For security reasons, the strip parity disk is stored on a disk other.
4. RAID - 5 improvement from the RAID - 4 in terms of improving performance.
5. Disk is usually used in the network server.
   

RAID level 6

1. It is the latest RAID technology.
2. Using the method of calculating parity for two reasons to anticipate the accuracy and error correction.
3. As with RAID - 5, parity stored on the disk other.
4. Have a high transfer speeds.

RAID Images

Tape Magnetic Emissions

• System using the technique of magnetic tape reading and writing, which is identical with the magnetic disk system.

• Medium magnetic tape, a track pararel, the old tape system bears fruit 9 tracks that allows storage one byte at a store one bit of parity on the remaining tracks.

• The system uses a new tape, 18 or 36 tracks as an adjustment to the width of word in a digital format.

• As the disk, magnetic tape, read and written in the form of blocks connected (continue), which is called physical records.

• Block-block is separated by gaps called inter-record gaps.

• Head magnetic tape is a sequential access device.

• Head must adjust the location of records that will be read or written.

• When the head is in place more of the desired records from the tape need rewind first, the new reading is done with the forward direction.

• Very different technology on the disk using the techniques of direct access.

• Lap speed magnetic tape is low so that the transfer of data to be slow.

• Pita begin magnetic abandoned replaced by the type of CD products.

Detect viruses in a computer using multiple antivirus engines Tips

Detect viruses in a computer using multiple antivirus engines

Virus detection and its removal are made through an antivirus program which finds out viruses in a computer and then possibly removes or repairs the virus problem. But today an interesting tip, how to scan your system without any installed antivirus program. You can scan any specific file for viruses, malware, worms and trojans on your system without any preloaded antivirus protection.

VirusTotal is a free service that facilitates you for quick scan to detect viruses, malware, worms and Trojans. Virus Total will analyze your system files using multiple antivirus engines. Virus Total is not a proper substitute of installed antivirus program, because this service works only when you will be connected to internet.

Now open the VirusTotal site to start scan process.


Now under the "Upload the file" section, click on browse button to select the virus affected file and press "Send File" button.

Here Virus Total will takes some time to upload file (depends upon the file size and internet speed).

Computer Evolution and Performance Part 13

Organization and Architecture Chip
- Increase the speed processor.

• In carried out primarily by reducing the size of "Logic gate."

>> "Gate" more, more meetings, the speed increases.
>> Processing time can be shortened.
- Addition of the cache size and speed.

• It is part of the processor chip.

>> Cache to reduce the access time is significant.
- Changing the organization and processor architecture.

• Improving the effectiveness and speed of execution.

• Processing in parallel.

Intel's Microprocessor Performance


The increase in capacity Cache
- Consists of two or three levels of cache between the processor and main memory.
- The increase in chip density.

• The more cache memory in the chip.

>> Faster access the cache.
- In the Pentium 10% allocated to the cache.
- In the Pentium 4 is allocated 50%.

New Approach - Multiple Cores
- Multiple processors on one chip.

• Large shared cache

- With one processor, proportionate increase performance straight with the increase of complexity.
- If the software can utilize multiple processor, the processor can mean two performance fold.
- So, take two simple processor in the chip better than one processor that is more complex.
- With two processors, cache it bigger.

• Consumption of power in the logical memory is smaller than the logical process.

- Example: IBM POWER4

• Two cores based on the Power PC.

POWER4 Chip Organization

Computer Evolution and Performance Part 12

Solutions
- Increasing the number of bits in one time

• Create greater DRAM

- Changing the interface DRAM

• Cache

- Reduce frequency access memory

• Cache more complex and is located on the chip

- Improve the bus system

• High speed buses

• Hierarchy of buses

I / O Devices
- The device needs for operation of I / O
- Need Throughput data that is large enough
- Processor can handle this task
- Problems in the transfer of data
- Solution:

• Caching

• Buffering

• High-speed interconnection buses

• More elaborate bus structures

• Multiple-processor configurations

Typical I / O Device Data Rates


The key: balance
- Processor components
- Main memory
- I / O devices
- Interconnection structures

Computer Evolution and Performance Part 11

Intel

• 1971 - 4004
• Microprocessor first
• All components of the CPU is a single chip
• 4 bits
• Following the emergence of 8008 since 1972
• 8 bits
• Microprocessor with special design application
• 1974 - 8080
• Intel is microprocessor with the general usefulness.
  

Increased speed

• Pipelining
• On board cache
• On board L1 & L2 cache
• Branch PREDICTION
• Data-flow analysis
• Speculative execution
  

Comparison of performance

• Increased processor speed.
• Increased memory capacity.
• Speed memory behind than processor speed.
  

Logic and Memory Performance Gap

Computer Evolution and Performance Part 9

IBM 360 Series

• Produced 1964.
• Instruction Set Similar or identical, in these various groups of computer models issued using the same set of instructions so that the support system and device compatibility severity.
• Operating System Similar or identical, this is a feature that consumers demand, so when the computer does not require the replacement of the difficulties in the operating system because the same.
  

IBM 360 Series

• The increased speeds, models are offered ranging from low speed to high speed for the use of the consumers themselves can be adjusted.
• Memory size is greater, the higher models will be increasingly large memory.
• Price increases, the higher the style then the more expensive price.
  

IBM 360 images