Majors: Computer science and economics
Thesis: “A Look Into the Future of Compressed Caching in Virtual Memory”
Summary: “We found a way computers could run way faster.”
PowerPoint slide about freeing computer memory storage
This graphic from Matthew Macoy’s PowerPoint presentation represents strategies for freeing up computer memory storage. The wider blue segments are regular files, the narrower files are compressed.

Imagine you’re sitting at a small desk, doing some book research, says Macoy. You can store your research materials on the desk surface or in the desk drawer. “Think of the surface as a computer’s RAM (random-access memory storage),” he says. “The drawer is the hard drive’s storage.”

Now say you’ve got a book open atop the desk. But you need to consult another book, which lies in the drawer. You don’t have room for both books on top. The first book, therefore, must go in the drawer to make space for the second. In computerese, this is called “swapping.” 

To get around such storage limitations, programmers have compressed those “books” to be much smaller in size (picture the book as a postage stamp), and then decompressed them as needed. Macoy’s thesis adviser, Professor of Computer Science Scott Kaplan, published groundbreaking work on this topic in 1999: now Apple, Microsoft and Linux all use a compression/decompression system.

“The old limiting factor with doing this trick, in the 1990s, was that each computer had just one processing core,” Kaplan explains. “So, you could only do strictly one thing at a time. Any time spent compressing and decompressing chunks of memory was time not spent running the program.” Today’s computers have four cores. In a decade, there could be hundreds. “Matt’s thesis projects out to the future how this trend of compressing and decompressing could work.”

To that end, Macoy came up with algorithms for several strategies, including “parallelism,” in which you reserve an “empty chunk” of RAM as a way station for storage overflow (like a second mini-drawer in the desk).

“Ever since I took ‘Intro to Computer Science,’ I loved it,” said Macoy, who grew up in Southport, Conn. “And I wanted to write a computer science thesis, even if I don’t go into the field.” Macoy will join Credit Suisse Investment Bank after graduation. And for this thesis, says Kaplan, “Matt truly invested himself.”