Scumbria, stop picking your nose...
SUMMARY:
"We've looked at the major technical factors. For cheap systems,
RDRAM does have some decided advantages. For servers, RDRAM
has some decided disadvantages. For everything else, it's about even
now, with DDR jumping ahead of current RDRAM systems, and
Willamette-class systems likely to leapfrog over DDR. From a purely
technical standpoint, for the average desktop, the data leans slightly
towards the RDRAM side.
But man does not live by technical factors alone. A far bigger majority of
people would prefer a Mercedes over a Taurus. Most buy Taurus'
because Mercedes cost a lot more.
In the next segment, we'll look at why RDRAM costs so much, how
much of that is due to it being inherently more expensive to make than
SDRAM, and how much of it is due to the politics of the situation."
overclockers.com
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All Credit to: Sander Sassen.from hardwarecentral.com...
"An important factor affecting latency is the utilization of the memory system. When it is servicing no other
transactions, the latency for an 'isolated' read transaction is different than when other transactions are being
concurrently processed. When 2-cycle addressing and levelization are factored in, the system latency for an isolated
read is comparable for SDRAM-based and RDRAM-based memory systems.
However, when the memory system is under higher load the answer can be quite different. When one or more
additional transactions are being serviced, factors such as bank conflicts and address bandwidth become important
issues. The higher bank count of RIMMs versus DIMMs means that the probability of bank conflicts occurring is
much lower. Therefore, the high latency and bandwidth penalties associated with bank conflicts occur far less often in
RDRAM-based systems than in SDRAM-based systems. Furthermore, as illustrated in the previous timing diagrams,
the need for 2-cycle addressing on an address bus used to specify both Row and Column addresses means that the
address bus may not be available to start a subsequent transaction in SDRAM-based memory. During periods of
higher memory utilization, when more than one request is sent to the memory controller, some memory requests
may be delayed waiting for the address bus. For these reasons, under higher loads RDRAM-based memory can be
much more efficient, achieving lower latency and higher bandwidth than SDRAM."
"Micron Technology recently presented a power analysis at the Platform 2000 conference. In this analysis, they
computed 'maximum' and 'typical' power consumption for modules using PC133 SDRAM, DDR SDRAM, and RDRAM. Maximum power consumption is important for determining power delivery constraints and worst-case cooling requirements. This study concludes that PC133 DIMMs dissipate a maximum power of 11.6 Watts while providing 1.1 GB/sec of bandwidth, while DDR DIMMs dissipate 9.1 Watts while providing 2.1 GB/sec. The maximum power RIMMs dissipate is 4.6 Watts, while providing 1.6 GB/sec. These results clearly indicate that RDRAM provides more Bandwidth per Watt than the alternatives..."
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