"éja, techniquement, la dream est au niveau de la ps2"
"Niveau mémoire la dream a 2mo dédier auson + 8 mo dedier au graphisme + 16mo partager servant aussi bien de mémoire vive, mémoire vidéo et mémoire son. "
encore un qui croit que lma PS2 est la ramasse cote memoire lis ca
Just to clear things up (I hate bias towards things) I am not anti-DC in any way. I own a DC with many titles as well as a PS2. However since I have researched into hardware (3D, CPU, RAM etc) ever since the NES days I thought I´d give my 2 cents on this whole issue. Especially for those who do not understand the differences between the two consoles. I remember making a similar thread many many years ago... If I could have found it I would have simply copied and pasted
Quote:
Originally Posted by Joe_news
Just a interesting little read I found on this website:
http://member.telpacific.com.au/trat2422/dc.html
Have to check out the chart on the page to get where this comes into...
- Despite the fact that the PS2 can display polygons at a rate of around 66 000 000 per second, it doesn´t have enough video RAM to store any decent amount with a great deal of textures also.
My god hasn´t this debate died yet -_- Unlike conventional consoles (anything prior to the Dreamcast) the PS2 was built to be purely next gen. Why do you think the early PS2 titles looked so poor? Because he developers tried to use the same old methods taken from the PS1, Saturn and Dreamcast. Its not going to work.
Sure the PS2 has a small amoutn of VRAM (of which many developers initially struggles with) BUT it was not designed to "store" data like all the other consoles before it. It was deisgned (like the PS3) to "stream" data. Thats right, streaming and storing are two totally different concepts.
Quote:
Originally Posted by Arstechnica
The GS´s 4MB of VRAM is embedded on the die, giving it an insane bandwidth of 48.6 GB/sec.
That bandwidth is more than ample to stream textures in and out. The trouble is back then developers did not catch on until Sony released more mature libraries fo them to work with.
Quote:
Originally Posted by Joe_news
The polygons still require about 40 bytes of memory each, and with the lack of texture compression, there isn´t enough memory to hold a great deal of polygons & textures at the same time. It may be able to draw the polygons at a fast rate, but when you don´t have all that much Video RAM to store them, it creates a “bottleneck.”
Indeed that is correct. If we were to use old school techniques. See how they mentioned the word "store"? What happened to the features the console was designed for, streaming? If people are going to compare consoles, then please understand both sides and their technologies.
Quote:
Originally Posted by Joe_news
The Dreamcast´s ability to only render the polygons actually visible and compress 20 - 25 MB of textures into it´s 8 MB of video RAM allows it to show highly detailed environments containing a large variety of textures & geometric detail with little effort.
Spot on I did like PowerVR´s theory back in the early days of PC Wars until ATi and nVidia took over. The S3´s Hardware Texture compression techniques (also found on the Gamecube and XBOX) were a great idea. I suspect that again, because the way the consoles work were different (Storing Vs Streaming) Sony did not bother paying the extra license fee for the technology.
Quote:
Originally Posted by Joe_news
The PS2´s “Graphics Synthesiser” processor has no ability to decompress textures in real time, which means that full size textures have to move through a small pipeline between the 32MB main memory and the GS´s 4 MB Video RAM cache.
True, it has no ability to decompress textures... Unless someone tells it to The GS is fully programmable right down to microcode (previously seen on the N64). The developer would have to build the technology engine themselves if they wanted to compress textures at such a level. Since however the Ps2 was developed using a different theory not many bothered to.
[quote=Joe_news]This then translates to a lack of variety in texturing.[.quote]
wtf? o_O Textures are developed by texture artists, of which then pass it on to the 3D modellers to apply the textures to the polygons. It is up to the developer how many textures they want to use (within limits). I understand that you can only have x amount of textures at one time depending on resolution, detail, bump-mapping, specular lighting etc etc effects applied but again, if things were played to the strengths of the console (DC texture compression, PS2 streaming) then there is not a problem.
Quote:
Originally Posted by Joe_news
With the Dreamcast rendering around 58 300 polygons on screen at 3 500 000 polygons per second giving a frame rate of 60 f.p.s. only around 2.2 MB of the Video RAM is used to store the polygons, where the other 5.8 MB is free for texturing & the display. That´s about another 1.8 MB over the PS2´s total VRAM left over. & with 5:1 compression that´s quite a good bit of room.
Nice numbers lol Here is the catch... Unlike PCs, consoles cannot be tested uniformly and fairly for performance. There are many PC benchmarks as you know (3D Mark etc) but how many are there for consoles? Can we (the end user) run these benchmarks on our consoles in front of us to check the numbers? Nope.
This area has always been where the PR people earn their bread and butter. Unless you have serious 3D knowledge I would take any numbers from any console with a pinch of salt.
Now back to the memory issue once again -_- They mention VRAM storing the polygon data but what the hell happened to the cachés? VRAM and cachés differ from their job but both have blazing fast speeds. A well used caché will give a huge amount of performance boost much more than VRAM could ever have to a certain level. If VRAM was the "holy grail" then the XBOX and XBOX360 with their uniformed memory system would kill everything in sight just on the VRAM itself. That of course is not true.
Quote:
Originally Posted by Joe_news
Now lets take the PS2. At 20 000 000 polygons per second, you´d get about 333 333 polygons on screen at 60 frames per second. Hmm, but if each polygon takes 40 bytes of VRAM that´ll take over 13 MB to store them all. & you can´t store 13 MB of polygons into 4MB of VRAM & still have room for textures now can you?
I´m sure you´ve seen the magical words once again. Just incase you missed it, it is "store".
Quote:
Originally Posted by Joe_news
Although there are some programming techniques that can help the severity of the problem, such as updating the VRAM on a constant basis with new textures from the main RAM as the game plays. But this can of course be done with the Dreamcast aswell. Other problems are that, unlike the Dreamcast´s Direct X support, the PS 2 doesn´t allow for this.
wtf? The PS2 doesn´t allow for streaming textures just because DirectX does? Someone hasn´t read both sides of the story... Also DirectX has nothing to do with textures on that level. DirectX is a 3D programming library developed to make coding easier (look what it did for the XBOX right off the bat).
Quote:
Originally Posted by Joe_news
Strictly speaking the Dreamcast CPU, and the PlayStation 2 CPU aren´t fully 128-bit. They are actually classed as 32-bit processors. If they were fully 128-bit, they could even out-perform the XBOX, which uses a 32-bit 733 MHz Intel Pentium 3, & even the GameCube.
That is partly correct. If we only look at "bits" and not about what the CPU´s are actually made of then its true. Thus far we only have mentioned "bits" and the number "32" but what happened to the VU´s (Vector Units) of the PS2, which is an integral part of the Emotion Engine (and thus the CPU) itself? Nothing has been mentioned thusr far but I´m working through this post as I read it...
Also just because things are the same "bit" does not mean they are of the same power and efficiency. Also the XBOX uses a Intel Mobile Celeron 733MHz CPU and not a Pentium III. The GameCube uses a modified PowerPC CPU by IBM (which is used in Apple Macs) and thus is totally different in architecture Vs an AMD or a Pentium CPU.
Quote:
Originally Posted by Joe_news
Currently the only CPUs which actually go beyond the 32-bit realm are the likes of processors such as the AMD Athlon 64. The 128 bit part of the Dreamcast´s SH4 is its floating point bus, & consists of four 32-bit instructions which are executed together, apparently. [128-bit computational processing capability.] The floating point unit is 64-bit, and the integer unit is 32-bit. Check out the following address for more accurate details:
http://www.segatech.com/technical/cpu/ )
Nice of them to mention that but omit that the PS2 can do exactly the same thing :: shrugs:: No mention of the Vector units either or the fact that the PS2 uses parallel processing on a much larger scale than just the CPU alone. I honestly wish such comparisons were done fairly instead of misleading people.
For a more unbiased review of the PS2 check out these links
http://arstechnica.com/ararticles/paed.../openps2.ars/1
http://arstechnica.com/reviews/hardware/ee.ars/1
http://arstechnica.com/ararticles/paed.../ps2vspc.ars/1
Now if someone were to tell me the guys at arstechnica don´t have a clue what they are talking about, they need a very cold shower. These guys do this for a living and know their technical details much more than I do. Their XBOX360 and PS3 stuff makes interesting reading too.
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Quote:
Originally Posted by Joe_news
Thought you all could learn some thing about the DC´s power )
Sadly I didn´t learn anything but more fanboy-ism -_- I mentioned a long time ago that teh DC was better in terms of texture compression and was a very clean and efficient platform to develop on but its not as powerful than the PS2.
C´est toujours le meme jeu que l´on nous sort... 
Si la tienne tourne autour d´une console de salon tu es bien a plaindre ! 
