Video benchmar

[bwbarbieri]

How do I measure the "bandwidth available beyond what is consumed by the screen refresh" as described in this article: http://homepage.mac.com/kpmiller/videobandwidth.html

This article uses Mac machines. I want to find the same quantity for 486 PCs using simple, old video cards (example: WG-1000VL/4...Cirrus Logic...FCC ID# E5YWG1000VL4...1995...32-bit VLB...1MB RAM...24 bit color...VESA v1.02...Cirrus Logic chip CL-GD5428-80QC-A).

I've tried 5 ways to measure frame rate. Each gives me a different result. In particular, for 640x480x8bit I get 8.9, 3.1 and 5.6 frames per second for three of the more controlled methods.

One program I have (Tunnel, http://active-hardware.com/english/benchmarks/benchmarks.htm) has a lot of controls, but I'm not sure what they all mean. Is there something a little more automatic, or an established procedure that I'm unaware of?

[DocEvi1]

I'm in england and the procedure is called "chucking". It is a very technical procedure that involves large amounts of lifting and a skip

You could try Sisoft Sandra, thats has something like that I'm sure.

And I do know that 486's make great routers, firewalls / proxies, message boards, run win98....we have about 40 of em at work which are going to do just that.

Stefan

[bwbarbieri]

SANDRA does not support video benchmarking, and is inadequate on older systems. Also, SANDRA works from within Windows and tends to be an information "gatherer", taking information from Windows. In other words, SANDRA will tell me what I installed and set. If I installed and set 'it', then I already know what 'it' is. I don't need software to tell me what I already know.

SANDRA is good for summarizing information about your PC system, not for determining what it really is. Better diagnostic software will read directly from hardware, and often runs in a DOS only mode.

I have made some progress since this post. For example, I found a program called MCLK that will tell me the video memory bandwidth in MHz. From this and the card bit width I can calculate the peak total video bandwidth. Since I only just finished this, I still need to confirm that the number I get makes sense. For the card I describe above, I get a bandwidth of 50.11 MHz on what I assume is a 32-bit video card (intended for use on a 486 machine; also there are 8 chips with configuration 256kb x4). This gives me a peak bandwidth of 191.2 MiB/s. Now the question is: Is ~200 MiB/s a reasonable value to expect on a board built in 1995?

Other questions: When was double buffering first introduced? How can I tell if a card is using double buffering? How can I tell if the memory is SDR or DDR? Is it true that Frame Rate = Fill Rate/Resolution? And this most important question: How do I clarify/understand why I get so many different values for frame rate from different programs, and what is the significance of each?