| Many people know just what they want when | | | | it cost less. Unlike the registered DDR1, |
| building a new system, or upgrading an existing | | | | unbuffered DDR1 can only be installed on one |
| system. They pick out the perfectly matching | | | | mother board to a maximum of 4 * 1GB. |
| CPU, motherboard and the video card combination | | | | DDR2 memory |
| of their preference, but when it comes to the | | | | This is the second generation DDR memory. While |
| memory, they simply have no idea, and much | | | | the 400MHz is the highest speed for DDR1, it is |
| less of what DDR memory is. If you are one of | | | | the lowest for DDR2. This means that DDR2 |
| such people, then here is all about the DDR | | | | picks up where DDR1 leaves off. Due to the |
| memory that you need to know. | | | | different latencies, a 400MHz DDR1 may |
| Why choose DDR memory? | | | | outperform a 400MHz DDR2, but the advantage |
| DDR (double data rate) is an evolutionary | | | | returns to DDR2 as soon as the speed reaches |
| memory technology based on SDRAM. The DDR | | | | the next step (532MHz) which DDR1 can not |
| SDRAM access is twice as fast as SDRAM, as | | | | reach. |
| data transfers occur on both edges of the clock. | | | | DDR3 Memory |
| It is fast, transferring data up to 2133MB/s. It also | | | | This is the third generation of the DDR memory. |
| consumes less power than the conventional | | | | It begins with a speed level of 800Mbps (400MHz) |
| SDRAM or other types of memories, with an | | | | as the lowest available. Today, the highest |
| operational Vcc of just 2.5Vcc instead of 3.3Vdc | | | | popularly available DDR3 speed runs at two billion |
| for SDRAM. | | | | data transfers per second. |
| | | | DDR memory compatibility |
| Which DDR do you buy? | | | | It’s not advisable to just walk into a shop and |
| Depending on your preference and your system, | | | | buy any DDR available for your system. You |
| you can get any of the DDR memory available in | | | | must consider the compatibility of the DDR |
| the market (DDRI, DDR2 or DDR3). Selecting the | | | | memory. You can use the memory selector to |
| right DDR variant is a very important factor in | | | | find compatible DDR, DDR2 or DDR3 memory |
| determining the overall performance of your | | | | upgrades, or the all new system scanner to scan |
| system. | | | | your system for the matching DDR memory. |
| DDR1 memory | | | | What to consider when choosing DDR memory |
| DDR1 is available as registered or unbuffered. | | | | Besides the compatibility, you need to check the |
| DDR1 has its address and control lines buffered to | | | | different latencies in the market, compare |
| reduce signal loading, and is more expensive than | | | | different brands available and their prices and |
| unbuffered DDR1. Unbuffered DDR1 does not | | | | other factors that will be of preference to you. |
| feature address lines and control line buffering, so | | | | |