SDRAM: Hype or the Futureby Anand Lal Shimpi on May 2, 1998 4:40 PM EST
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Eventually this trend caught on to the PC market, making its debut with Intel's 430VX Chipset, Although at most you would find 2 DIMM slots on any given VX board with a single DIMM slot being the norm. The PC industry decided to take DIMMs to a completely new level, instead of simply using the old asynchronous Extended Data Output standard (EDO) which boasted widespread use and an affordable price the industry chose to introduce a new type of DRAM. This new type of DRAM flaunted two major features: the ability to run at higher bus speeds more reliably, and support for synchronous data transfers. Here's when SDRAM finally made its introduction.
The BUS must not accelerate above 66MHz...
We all remember the huge jump from the 33MHz memory clock of the 486 to the 66MHz memory bus speed of the Pentium class systems. Well Intel wanted to keep the limit of the memory bus speed on our computers at 66MHz, and since the market seems to follow Intel blindly when it comes to things like this the memory industry specd EDO DRAM at a maximum operating bus frequency of 66MHz, and no more. However, it quickly became apparent that EDO RAM could be easily operated at bus speeds above 66MHz, although when reaching the 83.3MHz point stability becomes a tricky thing to achieve. Therefore when implementing SDRAM the bus speed specification was raised to the 100MHz-bus speed barrier, Intels next major jump. At the time this was only a plan Intel had decided on for their next generation processors. Since then we have finally started achieving bus speeds around the 100MHz mark in spite of the fact that Intel still hasnt released a processor designed for any bus speed greater than 66MHz. Is SDRAM a requirement for bus speeds above 66MHz? Absolutely not! As long as you have some quality EDO SIMMs they will not have any problems at bus speeds up to 83.3MHz, their stability at the 100MHz-bus speed is still questionable though. It is highly unlikely that any 100MHz-bus speed motherboards (which will most likely be based on the ALi Aladdin V or the VIA MVP3) will support EDO RAM anyway, so that limitation isnt something you should be concerned with.
When people go out to purchase SDRAM, their justification for doing so is that "they want to be able to use their SDRAM at the 100MHz-bus speed," what they arent aware of is the fact that until now we havent had any 100MHz-bus speeds to actually test those claims on. Sure a manufacturer can say that their SDRAM is rated at 100MHz, and should therefore theoretically work on any 100MHz-bus speed motherboards. The keyword there is THEORETICALLY; many ideas work in theory, however in practice they fail miserably. There is no guarantee that the SDRAM you buy today will work with the 100MHz-bus speed and there is absolutely no guarantee that the SDRAM you buy today will even work in upcoming motherboards.
So whats the real deal?
The question you all looking for the answer to is: "Will my SDRAM work with upcoming BX motherboards?" The answer to that question? Well, since there are no guarantees in life (especially not in the computer world) there cant be one straight answer, what will most likely happen is that SDRAM you buy today will be compatible with the upcoming BX based motherboards. Compatible doesnt mean functional, the SDRAM you can buy today will theoretically (dont you just love that word) work with a BX motherboard, whether or not it can stand up at the 100MHz bus speed is another question. Chances are that only the best quality SDRAM will survive with a BX motherboard and the 100MHz (+) bus speed. the tests that were run on ABITs LX6 - a 100MHz bus speed enabled Pentium II LX motherboard - indicate the following hypothesis: SDRAM in general will work at the 100MHz bus speed, however some modules have a tendency to work at the higher bus speeds than others.
ECC & EPROM necessary or just a marketing trick?
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