PC Hardtech

Memory is designed to be backward-compatible, so generally speaking, you can safely add faster memory to a computer that was designed to run slower memory. However, your system will operate at the speed of the slowest memory module.
One thing to keep in mind is that the memory does need to be the same type - for example, SDRAM cannot be mixed with DDR, and DDR cannot be mixed with DDR2 and DDR2 cannot work in a DDR3 system.
We recommend that you use the Crucial Memory Advisor™ or System Scanner tools to find the right memory for your computer. Rather than give memory modules catchy names, the industry refers to modules by their specifications. But if you don't know a lot about memory, the numbers can be confusing. Here's a short summary of the most popular types of memory and what the numbers refer to.

DDR3

DDR3 memory is the latest generation of memory for computing applications and offers many benefits over DDR2 including lower latencies, higher speeds, and more. DDR3 is not backward-compatible with DDR2. For this type of memory, a higher number represents faster memory, or more bandwidth. Occasionally DDR3 is referred to by a "friendly name" like "DDR3-1066" or "DDR3-1333". When written this way, the numbers after "DDR3" refer to the data transfer rate per second (/s) of the components.

Friendly Name	Industry Name	Peak Transfer Rate	Data Transfers/Second (in Millions)
DDR3-800	PC3-6400	6400 MB/s	800
DDR3-1066	PC3-8500	8533 MB/s	1066
DDR3-1333	PC3-10600	10667 MB/s	1333
DDR3-1600	PC3-12800	12800 MB/s	1600

DDR2 PC2-4200, DDR2 PC2-5300, DDR2 PC2-6400, and DDR2 PC2-8000

In DDR2 modules, the numbers that come after the "PC2" refer to the total bandwidth of the module. For this type of memory, a higher number represents faster memory, or more bandwidth. Occasionally DDR2 is referred to as a "Friendly name" like "DDR2-533" or "DDR2-667". When written this way, the numbers after "DDR2" refer to the data transfer rate per second (/s) of the components. DDR2 is not backward-compatible with DDR.

Friendly Name	Industry Name	Peak Transfer Rate	Data Transfers/Second (in Millions)
DDR2-400	PC2-3200	3200 MB/s	400
DDR2-533	PC2-4200	4266 MB/s	533
DDR2-667	PC2-5300	5333 MB/s	667
DDR2-800	PC2-6400	6400 MB/s	800
DDR2-1066	PC2-8500	8533 MB/s	1066

DDR2 PC2-4200 (commonly referred to as DDR2-533) memory is DDR2 designed for use in systems with a 266MHz front-side bus (providing a 533MT/s data transfer rate). The "4200" refers to the module's bandwidth (the maximum amount of data it can transfer each second), which is 4200MB/s, or 4.2GB/s.
DDR2 PC2-5300 (commonly referred to as DDR2-667) memory is DDR2 designed for use in systems with a 333MHz front-side bus (providing a 667MT/s data transfer rate). The "5300" refers to the module's bandwidth (the maximum amount of data it can transfer each second), which is 5300MB/s, or 5.3GB/s. PC2-5300 is backward-compatible for PC2-4200.
DDR2 PC2-6400 (commonly referred to as DDR2-800) memory is DDR2 designed for use in systems with a 400MHz front-side bus (providing an 800MT/s data transfer rate). The "6400" refers to the module's bandwidth (the maximum amount of data it can transfer each second), which is 6400MB/s, or 6.4GB/s. PC2-6400 is backward-compatible for PC2-4200 and PC2-5300.
DDR2 PC2-8000 (commonly referred to as DDR2-1000) memory is DDR2 providing a 1,000MT/s data transfer rate). The "8000" refers to the module's bandwidth (the maximum amount of data it can transfer each second), which is 8000MB/s, or 8GB/s. PC2-8000 is backward-compatible for PC2-4200, PC2-5300, and PC2-6400.

DDR PC1600, PC2100, PC2700, and PC3200

Like DDR2 modules, in DDR modules the numbers that come after the "PC" refer to the total bandwidth of the module. For this type of memory, a higher number represents faster memory, or more bandwidth. Occasionally DDR is referred to as "DDR400" or "DDR333," for example. When written this way, the numbers after "DDR" refer to the data transfer rate per second (/s) of the components.

Friendly Name	Industry Name	Peak Transfer Rate	Data Transfers/Second (in Millions)
DDR-200	PC-1600	1600 MB/s	200
DDR-266	PC-2100	2100 MB/s	266
DDR-300	PC-2400	2400 MB/s	300
DDR-333	PC-2700	2700 MB/s	333
DDR-400	PC-3200	3200 MB/s	400

PC1600 memory — which Crucial no longer carries - is DDR designed for use in systems with a 100MHz front-side bus, (providing a 200 mega transfers per second [MT/s] data transfer rate). The "1600" refers to the module's bandwidth (the maximum amount of data it can transfer each second), which is 1600MB/s, or 1.6GB/s. PC1600 has been replaced by PC2700, which is backward-compatible.
PC2100 memory — which Crucial no longer carries - is DDR designed for use in systems with a 133MHz front-side bus (providing a 266 MT/s data transfer rate). The "2100" refers to the module's bandwidth (the maximum amount of data it can transfer each second), which is 2100MB/s, or 2.1GB/s. PC2100 is used primarily in AMD® Athlon® systems, Pentium® III systems, and Pentium IV systems. PC2100 has been replaced by PC2700, which is backward-compatible.
PC2700 memory — the slowest DDR memory speed that Crucial now carries - is DDR designed for use in systems with a 166MHz front-side bus (providing a 333 MT/s data transfer rate). The "2700" refers to the module's bandwidth (the maximum amount of data it can transfer each second), which is 2700MB/s, or 2.7GB/s. PC2700 is backward-compatible for PC1600 and PC2100.
PC3200 (commonly referred to as DDR400) memory is DDR designed for use in systems with a 200MHz front-side bus (providing a 400 MT/s data transfer rate). The "3200" refers to the module's bandwidth (the maximum amount of data it can transfer each second), which is 3200MB/s, or 3.2GB/s. PC3200 is backward-compatible for PC1600, PC2100, and PC2700.

SDRAM PC100, 125MHz, and PC133

In SDRAM modules, the numbers that come after the "PC" refer to the speed of the system's front-side bus. PC100 memory — which Crucial no longer carries - is SDRAM designed for use in systems with a 100MHz front-side bus. It is used in many Pentium II, Pentium III, AMD K6-III, AMD Athlon, AMD Duron, and Power Mac G4 systems. PC100 has been replaced by PC133, which is backward-compatible.
125MHz memory is SDRAM designed for use in systems with a 125MHz front-side bus. 125MHz has been replaced by PC133, which is backward-compatible.
PC133 memory is SDRAM designed for use in systems with a 133MHz front-side bus. It is used in many Pentium III B, AMD Athlon, and Power Mac G4 systems. PC133 is backward-compatible for PC100 and 125MHz.

Older memory technology — PC66 SDRAM, FPM, and EDO

PC66 memory is SDRAM designed for use in systems with a 66MHz front-side bus. It is used in the Pentium 133MHz systems and Power Macintosh G3 systems. FPM and EDO speeds are written in nanoseconds (ns), which indicates their access time; the lower the number, the faster the memory (it takes fewer nanoseconds to process data).

Julian Sathyadason

Your PC was converted into smart phones..

Your smart phone is converted back to PC, and that is only through Windows 8..
It is boon for techies but a bit harder to the older generation..
But anyhow the next generation is only gonna rule

Gadde Kranthi Kumar

New features are: 1) Pins and Picture password protection 2) Synchronizing Windows settings across machines if we have multiple computers at home or at work. 3)In Windows 8 We can Launch ISO Natively

Varshinee Krishnamurthy

I started using windows 8 very recently. It was very difficult to get accustomed to it initially. Everything was very "un-windows" ish. There was no start icon in the task bar.. seriously? ?? Windows without windows start icon? ? eventually I found out a way to install it too . . but There are many visually appealing effects also.. the swipe screens are amazing. Swapping between windows and the left , right corners shortcut s are amazing. . Its definitely a new experience for ppl who would like to venture things

Venkatesh Saravanan

It is entirely different from w7. lots of new facilities are available and it wll take the people to next generation

Adithiyaa Venkat

It is not entirely diff from win7,.. Win8 is developed mainly focused on shortcuts and fast performance

Vignesh N Vicky

Windows 8 also contains two soft keyboards: an "enhanced" traditional keyboard, plus a new thumbs keyboard for non-touch typists.

Vignesh Vicky

Knowing the keyboard shortcuts for Windows 8 can save you a lot of clicking and dragging with the mouse, and make it easier to navigate the operating system.