I am currently waiting for the 1×4 GB DDR3 SODIMM memory module to reach at least 200 USD before it’s even reasonable to purchase. At the time of this writing, it’s nearly double that, so I have a little while to wait. While I’ve been collecting prices over at Other World Computing, I wrote a little script for GNU Octave to read in and parse an easily updatable list of prices and predict when 200 USD would be reached. The script is building upon some results I had previously.
There are a couple of funny little bugs* I haven’t taken time out to squash yet, but it doesn’t affect the mathematical result, so here it is.
My basic assumptions about the model is that the price is dropping quadratically. Of course, this assumption is obviously not perfect, considering it does not account for an obvious slowdown that will occur at some point. Since I only care about getting to 200 USD, then my assumption essentially is that the price will drop quadratically through 200 USD.
Using a least squares approximation from the data I’ve collected from OWC, I am expecting the price to hit my threshold on 12 Feb 2009.
* I’ll release the source script and an optimize MATLAB version that utilizes some vectorization that shows speed improvement up to 3X. Of course, for data this small, it doesn’t matter (what’s 0.001 s versus 0.003 s), but for larger data, the vectorization is a great way to get performance improvements. I don’t know yet if the vectorization could work with modification in GNU Octave.