kory@avatar.UUCP (Kory Hamzeh) (03/21/89)
A while back I posted a request for some information regarding raytracing times of various processors and FPA combinations. I just wanted to thank everyone who helped. I also got LOTS or requests to summaries and post the result, so here they are. Please note that these are not 100% accurate, these are timings experienced by various people. 10 Mhz 80287 80,000 flops 20 Mhz 80387 440,000 flops 20 Mhz Wietek mW1167 2,100,000 flops I don't have specific timing on the 16881, but I was told that it is very close to the 80387 performance at the same clock rate. As a rule of thumb, you can cut your tracing time in half by increasing your FPA performance by a factor of 3. This makes sense because, as all of you know, a ray tracer is not doing FP operations 100% of the time. Three thing to consider if you plan to use a Wietek chip: - Make sure you can get a hold of a compiler which can generate code for it. I use Xenix and as far as I know, there aren't any such compilers. - Make sure that you can feed it fast enough. - Unlike the 287/387 which does all internal operations in 80 bit percision (sp?), the Wietek does everything in 64 bit. This can lead to some percision losses. In my original posting, I had suggested a price of $1000 for a 80387. Well, I was wrong. I was assumming $700 for a 387 (which you can get one for about $400 nowadays) and $300 for the daughter card. After talking extensively to Mylex (the people that made my motherboard), they told me that the card plugs into on of the 16 bit I/O slots. As it turns out, the 387 will not be that much faster than the 287 that I currently have. I'm going to have to fork out another $4000 to get the new upgraded motherboard with the 387 socket. Anyone wanna buy a motherboard, cheap. :-) I hope that this posting answered some of the questions that various people had. PLEASE, lets not start any processor wars here. Thanks, --kory -- ------------------------------------------------------------------------------- Kory Hamzeh UUCP: ..!uunet!psivax!quad1!avatar!kory INTERNET: avatar!kory@quad.com