From: "George Kinney" Subject: Re: Vesa 2.0 is slower than 1.2 on my video card !!!!! Newsgroups: comp.os.msdos.djgpp References: Organization: The Unknown Programmers Message-ID: <01bc9649$c7c22620$c38033cf@pentium> NNTP-Posting-Host: 207.51.128.195 Date: 22 Jul 97 02:39:11 GMT Lines: 40 To: djgpp AT delorie DOT com DJ-Gateway: from newsgroup comp.os.msdos.djgpp Precedence: bulk Guan Foo Wah wrote in article ... > My video card's (Cirrus Logic Cl-54M30) bios doesn't support vesa 2.0 > but vesa 1.2. I install the Display Doctor 5.3a into my computer so that > my video card can support vesa 2.0. > > Then I ran the Allegro's Demo.exe. I choose vesa 2.0 linear frame > buffer and 640x480 mode with double buffer. When the game starts, it > reported the frame rate to be 16 fps. This is even slower than the vesa 1.2 > (which is about 24 fps with univbe and 22 without univbe). Can someone tell > me why vesa 2.0 is slower in my video card when it suppose to be faster > ??? anyone ?? You are *emulating* VESA 2.0 extensions. That means you have a driver processing all your interactions, then sending it on to the card. This is just more code that has to run everytime you plot something. This takes more time. It's like using an FPU emulator, instead of the native hardware. (Although I'll admit that univbe isn't nearly that slow :) Also, not all cards are compatible with the 2.0 extensions. I don't know about the Cirrus you have, but you might want to get some specs on it and find out. Personally, I have an S3 Trio32 on-board, and it seems to benefit from using a linear buffer. Sometimes though, it doesn't seem to have any effect. I've tried a lot of computers to check video performance, and the 2.0 extensions have resulted in a speed up on about half of them. So it's not the holy grail quite yet. Anyways, good luck.