Hi Daniel Schuh; The problem with EDRAM on the processor chip, in particular, is that most EDRAM uses more process steps than the logic used in CPUs. Consequently, it adds to the cost of the whole chip, not just the cost of the EDRAM portion. When the processor portion of the die is negligible in size compared to the EDRAM portion, EDRAM becomes very natural.
The thing to look for next is DRAM on some form of SOP (System On Package). That is, you make DRAM dice, a CPU die, and then combine them into a single package. This is what was done with the L2 cache until it was finally integrated. At first, there was a motherboard slot for L2 cache, and the user picked out how much he wanted. Then it was put onto the card containing the processor, then it was added to the processor itself. Each stage in this sequence was accompanied by lower build costs and higher performance. Right now, DRAM is in the earliest stage, it is still installed by the user in dedicated motherboard slot. This will not last more than a few more years.
Yesterday, I was forced to open up an old 486 I own, and was sort of surprised to see how much the technology has changed since then. The most obvious thing was that the processors back then didn't require a fan mounted on their heat sink. The other obvious thing was that back then, there were a lot more DRAM slots, I counted 8. More modern motherboards, with faster interfaces &c., are getting down to 2 slots only. I am certain that this trend will continue, and we will get to no slots within a few years. That will provide at least 20% better memory performance, as well as cheaper manufacturing costs (except that memory will have to be purchased a bit earlier in the production cycle).
The long term trend is towards the "pocket calculatorization" of the industry. Machine price under $200, includes all electronics, and built in display, no user serviceable parts, no user installed parts. When it breaks, throw it away and buy a newer model, which acts almost identically to the old one. This trend will hurt the CPU makers, such as AMD and INTC. But it will destroy the box makers, as the CPU makers cut them out of the production loop.
-- Carl |
