News: General

Memory Then, Memory Now

by Keith R. Wheeler

9/14/2004

Let’s continue our flashback comparisons of today’s systems to my first computer, a 1987 IBM Personal System/2 Model 30. That wonderful machine came loaded with 640 KB of random access memory while the 286 version of the Model 30 had 1 MB (1024 KB) standard. Well, things have come a long way since 1987. A new, budget-minded computer from Dell comes with a minimum of 256 MB of memory. In contrast, a more aggressively configured machine from Dell could come with 4 GB (4000 MB) of memory – just 4000 times the 1987 upgraded version. The highest rated memory speed for the Model 30 had a response time of roughly 100 nanoseconds. In order to compare that to the speed of today’s DDR2 chips which can perform multiple operations (read & write) simultaneously, we can figure that the chips run at a 400 MHz yielding a nominal response time of 2.5 ns. When taking into account DDR2’s multitasking, cut the response time in half to 1.25 ns, or 80 times faster than the 1987 chips. Unfortunately, I have not been able to locate pricing for memory circa 1987, I know with absolute certainty that the price per MB today is a tiny fraction of the cost in 1987. Assuming that memory costs account for roughly the same fraction of the computer’s overall cost (which is approximately 1/3 of the cost in 1987), it’s much nicer to get 256 times more capacity, enjoy 80 times the speed and have it cost 1/3 as much. Overall, memory today is about 61,440 times better today than it was 17 years ago – not bad!