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Frequently Asked Questions


  1. What is DDR Ram?
  2. What is the CAS number in the memory rating?
  3. What is ECC?
  4. What is Enhanced Latency?

Q: What is DDR Ram?

A: DDR SDRAM (double-data-rate SDRAM): DDR SDRAM is similar to SDRAM, but it transfers data on the rising and falling edges of the system clock, theoretically doubling the speed of SDRAM. Though DDR SDRAM was originally developed for graphics cards, desktop PC manufacturers now use it as system memory as well.

There have now been several generations of DDR memory, each faster than the previous and using a different slot size to avoid putting incorrect memory in a motherboard. Our configure pages will prevent you from selecting incorrect memory options when purchasing a system from Puget, but if you are building on your own then make sure to pay attention to motherboard specifications and any manufacturer-published qualification lists when selecting components.

Q: What is the CAS number in the memory rating?

A: CAS (Column Access Strobe) latency: CAL Latency usually has the most impact on memory performance. A common marketing term attached to SDRAM modules is either "CAS8" or "CAS9". For DDR3 RAM, a CAS latency of 9 clocks is currently the standard, with CAS 8 and 7 available on high-end RAM. Each is described with a rating number, where lower numbers are better. The rating is also dependant on the front side bus speed of your motherboard so the rating may rise on higher speeds.

Q: What is ECC?

A: ECC: Error Correcting Code or ECC memory includes special circuitry for testing the accuracy of data as it passes in and out of memory. That makes this a very popular choice for servers and high-end workstations.

Q: What is Enhanced Latency?

A: Enhanced Latency: EL refers to reduced latency cycles implying that these memory modules run at lower latencies than standard memory. Enhanced Latency DDR components increase the overall memory bandwidth at any given clock speed by lowering the amount of cycles required to initiate an operation.

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