Intel64 vs IA64

December 6, 2009

Intel64 and IA64 are two very different instruction set and architecture used in the Intel processor.

Intel 64 (formerly known as EM64T or IA32e) is the 64-bit extended instruction set based on x86 processor architecture. Modern processor that incorporated Intel64 technology could also run 32-bit application on a 32-bit operating system without performance losses although the 32-bit operating system would not be able to utilize any features in the Intel64 technology. The reason for such design is for backward compatibility which is the key to the success of Intel x86 processor.

IA64 however is based on an entirely different architecture. Only Intel Itanium processor employs IA64 architecture. It does not provide any backward compatibility with the IA32 software. the emulation of such 32-bit application is very slow. Originally Intel incorporated hardware emulation to the 32-bit application but since then Intel has been relying on software emulation.

For further information, you can visit the following sites:

http://en.wikipedia.org/wiki/X86-64#Intel_64

http://en.wikipedia.org/wiki/Itanium#Architecture


Transfer Rate (bps or Bps)

December 6, 2009

When we talk about data transfer rate, I am surprise that some IT professionals get confused with the differences between bps and Bps.

bps (bits per second) is usually used for raw data transfer speed between two identical devices. It is commonly used for USB, FireWire, Wi-Fi and networking devices.

Bps (Bytes per second) usually refers to the data transfer rate of files. It is commonly used to describe the data transfer rate of PCI bus, ATA, SATA and SCSI devices.

As you can see, different type of devices uses different type of transfer rate. Things starts to get complicated when you decided to purchase an external hard disk with USB, FireWire or eSata connection. This is where confusion started.

1 Byte = 8 bits. Therefore a 512kbps is 64kBps. The formula is as follows:

1k bits = 1024 bits

512k bits = 512 x 1024 = 524,288 bits

Since 1 Byte = 8 bits, 524288 bits can be expressed as

524288/8 Bytes = 65536 Bytes

To convert 65536 Bytes to KBytes

65536/1024 = 64kB

Therefore 512kbps = 64kBps

We can just simply divide 512 by 8 (512/8) = 64kBps

I had compiled a list of various system buses and its transfer speed for comparison purpose:

Mbps MBps
USB 1.0 2 0.25
USB 1.1 12 1.5
USB 2.0 HS 480 60
1394a (FW400) 400 50
1394b (FW800) 800 100
10 BaseT 10 1.25
100Base T 100 12.5
1000BaseX 1000 125
802.11b 11 1.375
802.11g 54 6.75
802.11n* 540 67.5
PCI 1064 133
AGP 2X 4264 533
AGP 4X 8528 1066
AGP 8X 17064 2133
PCIe 1x 2000 250
PCIe 2x 4000 500
PCIe 4x 8000 1000
PCIe 16x 32000 4000
ATA66 528 66
ATA100 800 100
ATA133 1064 133
SATA150 1200 150
SATA300 2400 300
eSATA 2400 300
Ultra SCSI 320 2560 320

Note:

* For 802.11n Wi-Fi, the transfer rate ranges from 300Mbps to 540Mbps. Existing working product works at 300Mbps. There is an attempt to push the transfer rate to a maximum of 600Mbps.

So if you bought an external hard disk with USB connection, the transfer rate will be limited to the USB transfer rate.

Please note that USB 3.0 (coming soon) with a transfer rate of 625MBps should solve the limitation of the USB transfer rate and in this case your maximum data transfer rate will be limited to your ATA or SATA hard disk transfer rate.

Please note that the list mentioned above are theoretical rate which is tested under a very specialized environment, in practice we can never achieve 100% of the advertised rate.

For Wi-Fi, please note that although there are a lot of products advertise as compliant to 802.11n specification. The official standard has not yet been finalized.

There is a study taking into consideration of network overhead as shown below:

Typical rate after consider network over head

range (unblock) Mbps MBps
802.11b (100m) 6.5 0.8125
802.11g (75m) 25 3.125
802.11n (125m) 200 25

The abovementioned table is just one of the many studies conducted to test the effective Wi-Fi throughput. For more updated results, please search the Internet.


Software Virtualization

October 5, 2009

Software virtualization has become popular lately. To solve some of the compatibility issue in Windows 7, Microsoft has incorporated a virtualized Windows XP in Windows 7.

For general user, one the advantages of using software virtualization is, it allows user to run very old application. For example, if you have an application that runs only on DOS, what you need to do is to install DOS on the virtualization software and install the application in the virtual DOS operating system.

As a general user, you can also test other operating system by installing them in the virtualization software. It is now very common for general user to run Windows with virtual Linux. It is more common for Mac users to run Windows operating system in their virtualization software since a lot of applications only runs in Windows operating system. However, you need to purchase additional Windows operating system license.

It is particularly useful for corporate environment, especially in a complex system environment with a mix of UNIX, Linux and Windows. For example, if an application only runs in UNIX, desktop user can install UNIX in their Windows operating system and run the particular application in the virtualized UNIX. Furthermore, virtual operating system can be managed from a virtual server, hence reduce cost in maintaining multiple operating systems. I believe that virtual software market will continue to grow to become an essential part of enterprise architecture. Virtualization software is particularly useful for IT profession in system testing and software development in multiple platform.

There is lots of virtualization software in the market. VM Ware is popular in the corporate environment. For home user, Microsoft Virtual PC is popular with Windows user. Sun’s VirtualBox is available in multiple platforms. Linux users install Xen or VirtualBox.

Microsoft Virtual PC was late in the game in the virtual market; it works well running Windows XP or any earlier version of Microsoft operating system. However, it does not perform well running Linux and it does not provide any integration between host and client OS. Sun’s VirtualBox is the better alternative. Available in multiple platforms, hardware emulation performs better if you install the guest additions.

I have tested a few of the virtualization software mainly VM Ware, Microsoft Virtual PC and Sun’s VirtualBox. For overall usability, I prefer VM Ware and VirtualBox. Please note that you need to purchase the software for VM Ware, and VirtualBox is free for home user.

End.


Transfer Rate (bps or Bps)

March 9, 2009

When we talk about data transfer rate, I am surprise that some IT professionals get confused with the differences between bps and Bps.

bps (bits per second) is usually used for raw data transfer speed between two identical devices. It is commonly used for USB, FireWire, Wi-Fi and networking devices.

Bps (Bytes per second) usually refers to the data transfer rate of files. It is commonly used to describe the data transfer rate of PCI bus, ATA, SATA and SCSI devices.

As you can see, different type of devices uses different type of transfer rate. Things starts to get complicated when you decided to purchase an external hard disk with USB, FireWire or eSata connection. This is where confusion started.

1 Byte = 8 bits. Therefore a 512kbps is 64kBps. The formula is as follows:

1k bits = 1024 bits

512k bits = 512 x 1024 = 524,288 bits

Since 1 Byte = 8 bits, 524288 bits can be expressed as

524288/8 Bytes = 65536 Bytes

To convert 65536 Bytes to KBytes

65536/1024 = 64kB

Therefore 512kbps = 64kBps

We can just simply divide 512 by 8 (512/8) = 64kBps

I had compiled a list of various system buses and its transfer speed for comparison purpose:

Mbps MBps
USB 1.0 2 0.25
USB 1.1 12 1.5
USB 2.0 HS 480 60
1394a (FW400) 400 50
1394b (FW800) 800 100
10 BaseT 10 1.25
100Base T 100 12.5
1000BaseX 1000 125
802.11b 11 1.375
802.11g 54 6.75
802.11n* 540 67.5
PCI 1064 133
AGP 2X 4264 533
AGP 4X 8528 1066
AGP 8X 17064 2133
PCIe 1x 2000 250
PCIe 2x 4000 500
PCIe 4x 8000 1000
PCIe 16x 32000 4000
ATA66 528 66
ATA100 800 100
ATA133 1064 133
SATA150 1200 150
SATA300 2400 300
eSATA 2400 300
Ultra SCSI 320 2560 320

Note:

* For 802.11n Wi-Fi, the transfer rate ranges from 300Mbps to 540Mbps. Existing working product works at 300Mbps. There is an attempt to push the transfer rate to a maximum of 600Mbps.

So if you bought an external hard disk with USB connection, the transfer rate will be limited to the USB transfer rate.

Please note that USB 3.0 (coming soon) with a transfer rate of 625MBps should solve the limitation of the USB transfer rate and in this case your maximum data transfer rate will be limited to your ATA or SATA hard disk transfer rate.

Please note that the list mentioned above are theoretical rate which is tested under a very specialized environment, in practice we can never achieve 100% of the advertised rate.

For Wi-Fi, please note that although there are a lot of products advertise as compliant to 802.11n specification. The official standard has not yet been finalized.

There is a study taking into consideration of network overhead as shown below:

Typical rate after consider network over head

range (unblock) Mbps MBps
802.11b (100m) 6.5 0.8125
802.11g (75m) 25 3.125
802.11n (125m) 200 25

The abovementioned table is just one of the many studies conducted to test the effective Wi-Fi throughput. For more updated results, please search the Internet.