This article is basically the NVIDIA Linux equivalent of the recent The OpenGL Speed & Perf-Per-Watt From The Radeon HD 2000/3000 Series Through The R9 Fury. However, on the NVIDIA side the proprietary driver is being tested since it performs better than Nouveau and NVIDIA's legacy driver series are still maintained so these binary blobs do run on modern distributions with recent versions of the Linux kernel and X.Org Server, unlikely the Catalyst legacy Linux drivers.
Testing is complete from the GeForce 8 series through the GeForce GTX 900 series. Nearly 30 graphics cards were tested, thanks to having many more of them on hand than on the Radeon side, thanks to NVIDIA's support. The exciting comparison with a ton of interesting Linux OpenGL numbers will likely be written and published by Tuesday.
Originally I was going to include the GeForce 6 series too with still having some GeForce 6600GT graphics cards. However, I ended up leaving those out since the 6600GT couldn't mode-set to 2560x1600 to match the other GPUs (and not testing at a lower resolution due to the newer GPUs then being very CPU bound). Additionally, with the 6600GTs having just 256MB of GDDR3 video memory, they aren't good for running modern OpenGL tests. Lastly, these cards from NVIDIA's "Nalu" days only support OpenGL 2.1 where at least ending with the GeForce 8 series still were able to run OpenGL 3.3 benchmarks.
Anyhow, I still decided to test the GeForce 6600GT on this Ubuntu 15.10 system: it worked! The GeForce 6 series is supported by NVIDIA's 304 proprietary driver series, which was last updated at the end of 2015 with new kernel and X.Org support. When installing the 304.131 driver on Ubuntu 15.10 x86_64, everything still worked! No headaches at all in getting this graphics card from 2004 to work on Ubuntu 15.10 with OpenGL 2.1 acceleration.
No driver issues to rant about. In fact, in all of the tests from the GeForce 8 through GeForce GTX 900 series hardware, there weren't any show-stopping issues to report. This is unlike on the AMD side where their "legacy" driver isn't maintained and on the open-source side they do support the hardware basically indefinitely, but regressions are common. With that recent Radeon comparison was an entire page devoted to the GPU issues/regressions encountered when trying to run older Radeon GPUs on the latest open-source AMD Linux driver stack.
So while you can complain about NVIDIA supporting the Nouveau driver project as much compared to AMD, at least on the proprietary driver side they are still doing a darn fine job supporting hardware for use on modern Linux distributions for their GPUs that are more than one decade old. The GeForce 6600GT tested was in fact the first GPU I bought for Linux benchmarking when starting Phoronix back in 2004.
Stay tuned for the very interesting GeForce 8 through GeForce GTX 900 comparison on Phoronix in the next few days.