I have an oldish GeForce 6200 EVGA PCI card 512Mb DDR2, with the (updated) Nvidia driver 304.128 installed on Lubuntu 15.1.
CSS and LXDE transitions are painfully slow, making me think they're not hardware accelerated at all. However, the benchmark GPU scores seem OK; 17s for FPU raytracing, 1.3 for FPU FFT. The driver is also managing two 1024*1280 screens; it's just all the animated transitions that are causing problems. Any ideas what's going on?
Edit: still haven't cracked this.
glxgears is showing 60fps, so the GPU is definitely capable of handling window transitions etc. Gnumeric is completely unusable. It takes about 1500ms to enter data into an individual cell, and the window can't be resized without artifacts. Libreoffice calc renders fine. I'm really baffled.