The 3d performance of the Virge was very poor, however S3 was renowed for its excellent 2d acceleration.
So what is the actual 2-d acceleration like vs newer chips like the Voodoo 3 or Radeon 9250?
It's poor. A Voodoo 3-5 and Radeons are close but a Virge and Cirrus Logic GD5446 are much slower.
Compare the Picasso 4 to the Voodoo 3 here:
http://www.amigaspeed.de.vu/I have an overclocked CV64/3D and a Mediator with Voodoo 3 and Voodoo 4. The Voodoo 3+ is significantly faster at almost everything. The only time the CV64/3D comes close is an operation that is limited by gfx bus speed and CPU speed.
As for the ability to do fast screen refresh. This is primary controlled by the RAMDAC, once video cards could update a 1600x1200 image in non interlace, it was pretty much fast enough. Again this is not necessary a direct function of 2-d acceleration.
Screen modes near their bandwidth limits do not perform well. The GPU is spending it's time refreshing the screen and the gfx memory is saturated leaving less to do operations on the screen. The Virge in my Cybervision 64/3D does overclock nicely and offers satisfactory performance at 800x600x16 which is a huge upgrade over ECS. Bump that up to 24/32 bit or the resolution much and it's not so great anymore. The Voodoo 3 has no noticeable slow down in 2D until I get to 1280x1024x32 or 1600x1200x16.
Why do you think the Picasso IV "better" than the Cybervision?
The P4 used faster memory and had a little faster gfx bus (original CV64 had the fastest gfx bus). If P5 had upgraded to a Virge DX or later (rumor has they did in some later CV64/3D cards) and clocked it up a little, they would have been competing with the P4. The P4 has some nice features but the 3D in the Virge is better than nothing too. It's actually more worthwhile on a slow CPU like the Amiga despite it's bad reputation on PC's with much faster CPUs back in the day.
