Path: chuka.playstation.co.uk!news From: Developer Support Newsgroups: scee.yaroze.freetalk.english Subject: Real PS speeds.... Date: Sat, 23 Aug 1997 13:03:32 +0100 Organization: PlayStation Net Yaroze (SCEE) Lines: 96 Message-ID: <33FED194.5D74@interactive.sony.com> References: <5tk1rp$3qt7@chuka.playstation.co.uk> <33FD5C48.27BF@cobradev.demon.co.uk> NNTP-Posting-Host: 194.203.13.10 Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Mailer: Mozilla 3.01 (Win95; I) I thought I'd better correct some fallacies about the 'speed' difference between Yaroze and full PS libs. The 360k polys per second ( pps ) is a marketing number that represents the limit of the gpu hardware when drawing a single flat poly repeatedly ( no gourard / no texture ) - As such it is pretty unrealistic for programming purposes ( although it is strictly correct ) running several games through a proffessional program analyser the 'real' pps count ranged as below. ( I only did this because I was bored, and I had 15 minutes to spare - So I wont be producing a hughe list ) ( Note: These numbers don't represent maximums, just what was happening at that particular stage/point in the game ) Porsche Challenge 30,000 pps. Penny Racers. 64,000 pps. Soul Edge. 53,000 pps. Rage Racer. 45,000 pps. Terra Incognita(yaroze) 28,000 pps. Snave (yaroze) 40,000 pps. These represent the drawing throughput for these games. ( In all cases, the drawing time is less than the cpu time ) Although Penny racers seems to be drawing more pps, it actually has the slowest frame rate of all of the games. In my estimation the maximum speed up going from good yaroze code ( that uses all of the tricks possible with LibPs ) to good proffesional code (inline assembly and low level hardware access) is around 2 times. If you look at the differences between FTP test using the Yaroze, and RayStorm ( from Taito ) using the full devkits, there isn't really much technical improvement. Cheers, Colin. colin adams wrote: > > Paul_Holman@Playstation.sony.com wrote: > > Thanks to all who have contributed to this discussion, it has > been very enlightening. > > gl> The Yaroze libraries don't contain the GTE functions > gl> which are what give the PSX 360K polygons a second rather > gl> than 60K or thereabouts. > > Wow! that's a massive difference. Approximately 1/6 of the speed! > Lets hope there will be a Yaroze libs upgrade soon? I knew the libs were > slower but I didn't expect such a vast Difference. This will definitely > stifle some of the things I had planned. (check out Room 3 in my demo > for an > example of slow-down). I may speed up the VCR to compensate :-) > > P> We're planning to have two demo pods running a compilation > P> disc that we've put together with the "best" Yaroze games and demos > P> from around the World. > > I will be going to ECTS so I'll see you there. Being a subscriber to CTW > means I already have my "Fast-Lane Pass" so no queuing for me :-) > I'll be there on Sunday. > > P> The deadline for this will be the end of this month (to allow us time > to > P> finish the disc and test it.). Please let us know if you'd like your > P> work included (use scee.yaroze.mydemos). > > I will take a pass this time round as I've just acquired a Graphic > Artist & We will > Embark on a Major Rework of the project now we are aware of the > limitations Yaroze > imposes. I would like to see a list of the demos you aim to include > though, > as it will give me a insight as to the competition. :-) > > P> If this move is popular. we could also produce a "compilation disc", > P> for sale to Yaroze Members, in time for Christmas, so that you can > P> give copies away to your friends and family etc. Let us know what > P> you think of this idea, and we can look into the feasibility. > > Hope your serious about this. I will aim to produce a better demo to > include on > this disk. (hey, stop playing Resident Evil I want to code). Hope you > set the charts > up too. Again Thanks for listening & keep the faith. > > -- > Colin Adams > Cobra Developments > Email: colin@cobradev.demon.co.uk > See HSFK v 0.4a PlayStation Yaroze Demo at-: > http://www.cobradev.demon.co.uk/