The GPU Index: a curve closer to the market

We keep improving racingtech.fr so the information we put in front of our visitors is ever more reliable. The latest change is a targeted improvement to the GPU Index, which shows, for each graphics card, the median second-hand price gathered from Leboncoin listings. The median is the « middle » price: half the listings sit below it, half above. It's more honest than an average, which a single crazy listing can drag upward. We've just refined not that number, but the curve that shows how it moves over time.

The problem: a sawtooth curve

Until now, each point on the history was the median of that single day. Yet on thinly-listed models — sometimes just one or two listings on a given day — a single unusually-priced listing, an over-optimistic seller for instance, was enough to send the curve leaping that day. It didn't happen every day, but when it did, the jump was dramatic. The result: a jagged, sawtooth line with spikes that didn't really reflect the market. A spotted example: an RX 6800 XT whose median sits around €380 could show spikes as high as ~€600.

The fix: a 7-day rolling median

Now, each point on the curve is the median of every listing from the past 7 days, no longer just that single day. In practice, we no longer rely on a single day's listings, but on the past 7 days. A lone overpriced listing no longer throws the curve off, and the day-to-day jolts fade away.

These occasional jumps are now smoothed out. The curve stays as close as it can to the market trend.

Want to see it for yourself? The median price, the trend and the smoothed history of every card are waiting for you on the GPU Index.