Well, I apologize if anyone thinks I jumped the gun a bit. After seeing manufacturers (mainly Sega, but I do recall during the creation of their consoles Microsoft and Nintendo saying things about XBox and GC being 128 as well) and every single specs site I can find saying the Dreamcast has a 128-bit processor (or in some cases, a 128-bit graphics processing engine, although that sounds a bit incorrect), I got a little defensive after what I felt was a very agressive approach by antime - something along the lines of, "Prove it! Come on, prove it!" that I didn't take very well - plus, like I said, I wrote the post at 5 am. So I'm completely open to someone really explaining to me how all this works, but so far all I've heard are a lot of, "You're completely wrong and making up numbers, and in denial and the companies lie, it's really 32-bit" without any backing information to go along with it. In my defense, my awareness of "x-bit systems" is rather limited - from what I know, it is usually something to do with the amount of bits a processor can address at a time or something like that (and then someone gets smart and says, "well, even though the processor is x-bit, such-and-such part of the system is only 32-bit, so..." like with the Jaguar). So if someone would care to explain this all, please do, but don't fault me for getting defensive when all I'm met with is, "You're wrong, don't believe everything you read, and we're right."
Consoles: 4-bit, 8-bit, 16-bit, 32-bit, 64-bit. A processor's bittage (lol) revolves around it's bus' width. A 64-bit processor will take data in 64-bit chunks natively. Up until recently though, the public DID care about bits, I think this ended with the N64 which was the last 64-bit console. Media hyping bits is much like how they hyped a game's megabit count. A 4M game in the 80s was impressive... Neo Geo games still sport an (inaccurate) bitcount. Two consoles that should be pointed out are the PC-Engine and Neo Geo. PCE is 8-bit, it doesn't matter if it "has a 16-bit GPU" (I'm not even sure if this is true.) It's core CPU, 6502 based, the same as the FC, the same as the 1977 Atari VCS(!) is 8-bit. The Neo Geo has been commonly dismissed as a 24-bit console. A 16-bit CPU plus 8-bit dedacated sound processor don't make it a 24-bit console. If that were the case then Sony's PS3 based on that cell-CPU crap would be like 32768 bit or a 32k processor (blasphemy)
So that means that a console's "bittage" isn't nessicarily an indicator of its "power" power or whatever, is that correct? So what exactly is the Dreamcast then? I've seen several tech specs sites on the internet that state the processor is 128-bit, but there are also a few that say 64-bit. And with the Turbografx/PC Engine: It was hyped as a 16-bit console, but the truth was, like you said, it only had a 16-bit GPU (which explains why the graphics are so nice on the thing) but the main processor was just the 8-bit 6502 the NES et al. used. EDIT: By the by, I just noticed this, but how did you get a custom title? Make a deal with the devil? ;-)
I always thought it was the color palette that made the TG16 shine. . .sure kicked the Genesis and its weird affection for that dull purple color in the ass. . .
GSL...The Devil=ASSEMbler When he was tweaking the boards early on, I was talking to him, and he asked me if I wanted one. I was too stupid to come up with one fast enough and missed out....I could have been a "Game Genie."
I sorta figured that - hope he's not offended by my insinuations... :smt102 On a brief offtopic, ASSEMbler, if it isn't a lot of work, there's an idea for a bit of income for offsetting teh costs of the site and board - sell custom titles for a cheap price ($5-$10 or so) on a one-time/yearly/twice-yearly basis - I think a few people might bite.
128 bit Well... if you did your homework properly, you would see that the SuperH SH4 processor in the Dreamcast is 128 bit... now what does that mean? It means it [the cpu] CAN address 2^128 (~340,282,366,920,938,463,463,374,607,431,770,000,000) on the address bus. Now whether the complimenting hardware supports this or not, I have no idea (The i386sx that had a 32 bit core, but a 16 bit data bus and 24 bit address bus). Also, this means that the the largest opcode the processor can process is 128 bit (16 bytes). Also I think the registers are 128 bits. I could be worng on that one. I havent done anything with a SH* processor for years.
I always thought a CPU's "bitness" is best measured by the size of its GPRs... otherwise the 6502 would be '16 bit' (but the Z80 has 16bit GPRs making this a bit moot)... I find it hard to believe that the SH4 can actually address 2^128 bytes of memory. disclaimer: I'm somewhat drunk, sorry if this doesnt make sense :smt033
The SH4 has a 32-bit address space and 32-bit GPRs. The Z80 GPRs are 8-bit but some instructions use pairs for addressing.
actually this gen only the ps2 is a true 128 bit processor me thinks i really don't care though at the moment...go games~
I was a bit wrong I was a bit wrong about the SuperH SH-4 processor, I dont know what I was thinking of... anyway, I dug up the actual specs for the beast: http://www.renesas.com/eng/products/mpumcu/32bit/sh/sh7760/index.html You will see under the DMAC section: Transfer data size: 8, 16, 32, or 64 bits, or 32 bytes Now the 32 byte DMAC transfer, after doing a little digging, you will find it is done in a two cycle pass... which makes this capable of "technically" (used quite loosly) transfer 128 bit per clock cycle or data between two IO devices. I guess thats how they can call it "128 bit"[/i][/quote]
No, they call it 128-bit because the matrix math instructions use vectors of 4 32-bit single-precision floats. This is called a "graphics engine" in the preface of the Renesas docs.
well, if we stick to that nomenclature then my wall decoration (386 mobo with a 87DLC FPU) is 80 bit :smt033 Nowadays X86 SIMD instructions use 64 and 128 bit registers so that would make the Xbox 128 bit :smt019
