February 20, 2014

NVIDIA GeForce 750 Ti: Great graphics, bad graphs?

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NVIDIA have just released their new GeForce GTX 750 Ti card, based on the Maxwell chipset. It seems like a great card at a pleasant price point and I downloaded NVIDIA's whitepaper. One thing that caught my eye is a graph comparing the GTX 750 Ti's performance to the GTX 480, the flagship card four years ago. It is terribly misleading. This is what it looks like:

GTX 750 Ti

GTX 480

1.2
1.0
0.8
0.6

Battlefield 4

Far Cry 3

Batman: AO

Heaven 4.0

GRID 2

Crysis 3

3DMark Firestrike

BioShock Infinite

Tomb Raider

Metro Last Light

Valley

Looks great, doesn't it? At first glance, you might think that there is an improvement almost clean across the board and it looks like GRID2 and BioShock Infinite perform marginally better on the old card and only 3DMark has a significant reduction, by half. Actually, it's quite the reverse! When making such a comparison between graphics cards, it makes sense to consider the older card the baseline reference. That would mean normalising its performance to 100% and placing its bars on the left of those of the newer card. This is because people in the western world expect an axis of time to go from left/old to right/new. NVIDIA effectively made the newer card the baseline, so the way to interpret this graph is not "how does this new card perform?", but as "how would our old flagship card fare when compared against this latest offering?". That is quite misleading in a whitepaper for the newer card and I have to wonder whether it was done on purpose. Another thing to keep in mind is that the vertical axis starts at 60%, so the length of the bars does not correspond linearly to the data. This is a common way to amplify the differences between data points that are close together. Here's the same data presented in a more sensible way: