3.3 1995s
- EDO (extended Data Output) DRAM is the most common type of asynchronous DRAM
or in other word called hyper page mode DRAM. It is faster than FPM memory because new access to the memory can begin before the last one finished. Its speed is just a little faster than FPM memory. EDO memory is not suitable for high-speed (75 MHz and higher) memory buses where it allows 5-2-2-2 system timings at 66MHz when using a chipset as support. Normally, some of the older systems will run EDO as FPM memory or will not work at all with it.
- Burst Extended Data Out (BEDO) DRAM was introduced later than EDO. BEDO memory is much faster than regular EDO. It allows higher bus speeds than EDO with supporting chipset. DRAM performance improved with BEDO memory at very little additional cost. Its performance can compete with SDRAM, but SDRAM won out because the supporting chipsets used by SDRAM is more popular.
- Synchronous DRAM (SDRAM) is the newer type of the DRAM. The term synchronous means the timings is limited by the clock edge where it is tied to the system clock. SDRAM supports 5-1-1-1 system timing when a supporting chipset is used. It is faster than EDO DRAM, therefore it replaces EDO DRAM.
3.5 1997s
- The earliest type of SDRAM is PC66 SDRAM. It runs stable on the 66MHz bus speed.
It supports 5-1-1-1 system timing. It is divided into two types which is ECC (Error Correction Code) and Non-ECC.
3.6 1998s
- When the standard SDRAM get unstable or could not reach 100MHz using the system cycle 4-1-1-1. PC100 replaces SDRAM in the marketplace. The quality of PC100 is measured in the amount of layers of printed circuit boards (PCB). Usually the number of layers of PCB is up to 6 or 8 layers.
3.7 1999s
- RDRAM (Rambus Dynamic Random Access Memory) is a type of DRAM that developed by Rambus, Inc in1999. RDRAM can transfer data in the speed of 800MHz and is used in Intel Pendium 4 processors. A computer with RDRAM can offer the highest performance of graphics, multimedia and etc. A new version of RDRAM is called nDRAM which transfer speed is up to 1600MHz.
3.8 1999/2000s
- PC133 SDRAM is introduced. It can run on a faster rate than PC66 and PC100 SDRAM. It increases the speed limit where it can run on a faster bus, therefore the total bandwidth is increase.
3.9 2000s
- No longer RDRAM and PC133 SDRAM were introduced to the market, a new type of memory developed, that was DDR SDRAM.
- At the first, what is DDR SDRAM? Is it similar to the previous memory type? Let us compare between DDR SDRAM with DRAM. DRAM has high potential bandwidth because every internal read is actually a strip of many thousands of bits. To make use this advantage more effectively, the DDR SDRAM was developed, which the DDR stand for Double Data Rate, shows this type of memory has double data rate interface. The DDR SDRAM uses the same commands with DRAM, accepted once commands per cycle, but the DDR SDRAM reads or writes 2 words of data per clock cycle, double up the minimum read or write unit, to 2 consecutive words, that meaning greater speed compare with DRAM.At 2000 year, the speed limit of the DDR SDRAM was only until 266MHz, meaning the memory only can speed up until 266MHz at that current time.
3.10 2001s
- After one year of technology growth, the DDR SDRAM speed limit increase from 266MHz to 333MHz, the DDR-333 can perform faster then DDR-266 even the two RAM are similar to each other.
- eDRAM are developed and opened to market at year of 2001, an eDRAM are much more different to a DRAM or SDRAM. The major different between eDRAM with other RAM was the eDRAM are integrated on the same package as the processor, so the eDRAM also called embedded DRAM. This kind of RAM contain wider buses, higher speed, due to much higher density, larger amounts of memory, but different processor have different manufacturing way make the integration difficult, and higher cost needed to package several dies on a chip. Normally this kind of RAM used in game consoles, such as PS2, PSP, Nintendo Wii. The speed limit of the eDRAM can go up to 450MHz, even higher then the DDR SDRAM.
3.11 2002s
- At year of 2002, again the DDR SDRAM was developed to be more effective and fit to the needs of the user, the limit speed of the RAM increased from 333MHz to 434MHz. But still the DDR SDRAM of 2002s year is similar from the previous DDR SDRAM just the speed of the RAM is developed to perform faster.
3.12 2003s
- Same with 2002s year, the DDR SDRAM was developed the performance speed to be faster, the speed limit of the 2003 DDR SDRAM increased from the previous 434MHz to 500MHz. Are the coming years will just increased the DDR SDRAM performance speed year by year?
3.13 2004s
- Instant of keep increasing the speed of the DDR SDRAM year by year, at the year 2004, a new RAM was developed to replace or we can say be sifted out the previous DDR SDRAM. The new RAM that developed at 2004 year was a DDR2 SDRAM. The name of it was similar to DDR SDRAM, meaning the DDR2 SDRAM is very similar to DDR SDRAM; the DDR2 SDRAM just doubles the minimum read or write unit again, to 4 consecutive words, mean the DDR2 SDRAM can read or write 4 words of data per clock cycle, also the bus procedure was also simplified to permit higher speed operation. Besides that, an extra address pin was added to allow 8 banks on the RAM chips, mean we can find there are 8 black chips (that called bank) on the RAM chips, compare with the previous DDR SDRAM that only have 4 banks on the RAM chips.
- At year of 2004, the DDR2 SDRAM speed limit was only until 533MHz, meaning the memory can just speed up until 533MHz at that current time.
3.14 2005s
- The technology of computer already much more advance at 2005 year, the DDR2 SDRAM speed limit was increased to 800MHz from 533MHz only in one year, the previous DDR SDRAM took many years to increase the speed limit from 266MHz to 500MHz.
3.15 2006s
- At 2006 year that was the last year, the speed limit of the DDR2 SDRAM were not increased, it maintain at 800MHz, but at 2006 year most DDR2 SDRAM available at PC market have only the operation speed from 667MHz to 800MHz, meaning the operation speed below 677MHz are difficult to find at the market, such as the DDR2-400 and the DDR2-533.Most of the user prefer used the DDR2-667 or the DDR2-800, so the DDR2-400 and DDR2-533 were sifted out from the PC market.
3.16 2007s
- In this year, a new RAM are developed and introduce to the PC market, this RAM have higher performance speed than the DDR2 SDRAM, similar to DDR2 SDRAM the new RAM is call DDR3 SDRAM. The DDR3 SDRAM being made commercially, but the computer systems able to use them are not expected until the late of 2007.The DDR3 SDRAM doubling the minimum read or write unit to 8 consecutive words, meaning DDR3 SDRAM can read or write 8 words of data per clock cycle, and the DDR3 SDRAM permit the doubling of bandwidth and external bus speed. To double up the read or write unit, the bank on the RAM chips also double up, extra address pin add to permit 16 banks on the RAM chips.
- The DDR3 SDRAM speed limit currently is in the range of 1066MHz to 1333MHz, the speed limit have high difference with the DDR2 SDRAM that only perform the speed limit at 800MHz. The higher performance speed for the RAM will develop in the future, are the DDR SDRAM will stop the trend at DDR3 only? Or the DDR4 will develop at the future?
4. Advantage And Disadvantage
In now days, every computer should have a memory (RAM) in their system unit, the RAM is the main memory for the computer to hold the data and instruction. Now let us discuss about the advantage and disadvantage of using RAM.
4.1 Advantages
By using RAM, the computer become more reliable and efficient.
How could we say that ?
- RAM allow user to read the data in fast and in a constant time regardless its physical location or relation to the previous data, the data can be read by user at the constant time make the computer become efficiency. For example, when a user needed to read the certain data or information, they just need open the data stored in the computer memory and the data will display itself on the display device of the computer.
- The data can be store in RAM and read from it by any order because the data is integrated circuit. The RAM able to keep the data more reliable then keep the data physically because the data is integrated circuit. For example, if the data are keep in paperfile or document, the file might be easily damages or deteriorate after few years later and the data will lose, but if the data are keep RAM in a digital document form, the possibility the data lose are more lower than keeping the data in a paperfile or document.
- The data are more easier to modify. For example, to modify the data on a physical storage media such as paperfile, notebook, user need to erase the data and rewrite it again on the physical storage media, and yet the data will became messy, but if the data are store in RAM, the user able to modify the data by using computer, that makes the modifying process become more easier and takes only a short period of time.
- Disadvantages
Using RAM bring advantages to user but it also bring the disadvantage to the user.
- RAM cost more expensive then other memory media. The RAM price is base on the RAM performance speed ,the more fast the RAM able to perform, the more expensive the RAM cost.
- The RAM is a volatile memory. That only able to store the data temporary only, when the power turned off, the data store in RAM will lose. To prevent the data lose when the power were turned off, user need to stored their data in the secondary memory that is a hard disk.
- The RAM has limited spaces to store data. The capacity of a RAM is limited, cannot hold/store too many data that more then the RAM capacity.
5. Others
6. Conclusions
The evolution of memory(RAM) will continue evolving as the technology of human keep increasing. The future memory might have greater speed limit, the disadvantage of the memory might be improve until there are no disadvantage, and a perfect memory will develop at that time. But, all this are just conjecture, nobody will know what will happen at the future, while we just can wait and see how human intelligence keep going on.
7. References
Kozierok, C. M. 17 April 2001. The PC Guide URL
Risley, D. 30 March 2001. The PC Guide URL
DEW Associates Corp. 27 January 2001. The PC Guide URL
Jupitermedia Corp. The PC Guide URL
Wikimedia Foundation, Inc. 6 July 2007. The PC Guide URL
Memory Suppliers, Inc. The PC Guide URL
Shelly G.B., and Cashman T. J., and Vermaat M. E. eds. 2007. Discovering Computers Fundamentals Third Edition. Thomson Learning, Inc.
8. Appendixes
8.1 The Figures of RAM
Resources from:
Figure 8.1: This is DRAM that introduces to PC market at 1970 year.
Resources from:www.epinions.com
Figure 8.2: This is FPM RAM that introduces to PC market at 1987 year.
Resources from:
Figure 8.3: This is EDO RAM that introduces to PC market at 1995 year.
Resources from: Encyclopedia-online.info/RAM
Figure 8.4: This is PC66 SDRAM that introduces to PC market at 1997 year.
Resources from:
Figure 8.5: This is PC100 SDRAM that introduces to PC market at 1998 year.
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Figure 8.6: This is RDRAM that introduces to PC market at 1999 year.
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Figure 8.7: This is PC133 SDRAM that introduces to PC market at 1999 and also at 2000 year.
Resources from:
Figure 8.8: This is DDR SDRAM that introduces to PC market at 2000 year, but the higher speed limit of this RAM is introduces to market at 2001, 2002, and 2003 year.
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Figure 8.9: This is eDRAM that introduces to PC market at 2001 year.
Resources from:
Figure 8.10: This is DDR2 SDRAM that introduces to PC market at 2004 year, the higher speed limit of this RAM are introduces to market at 2005 and 2006 year also.
Resources from:
Figure 8.11: This is DDR3 SDRAM that introduces to PC market at this year, that is 2007 year.
8.2 Task Division Table
Table 8.1 – Task Division For The Paper Work Of The Assignment
Table 8.2 – Task Division For The Presentation Slide Of The Assignment
