console speeds....

[blockers]

Hi.

Basically, i was looking for an N64 emulator and found the spec's of the N64 it self. The most important two being

CPU: MIPS 64-bit RISC CPU (customized R4000 series) , Clock Speed: 93.75 MHz

I know that this is a 64-bit console. Does it mean that it has a 64bit CPU, at 93.75mhz? where as my computer would be 32bit CPU, at 1866mhz?

How has it taken so long after the console to make 64 bit chips? was it actually a 64bit processor?

I dont really understand what is going on, and know that there is a hell of a lot of difference between what a computer is doing and what a console is doing.

Can someone try and explain plesae?

much appreciated
will

[Benjamin]

There have been 64-bit CPU's for a long time. Sun MicroSystems has been using them. Apple (G5), Athlon 64 was the first 64-bit x86 CPU.

[Stoo]

There have been a whole bunch of 64bit processors already, most of them being RISC chips from the likes of MIPS & DEC.

For some reason Intel decided to stick with the CISC design for the desktop and start on the mantra More MHz = Better, and dragged anyone else who wanted to compete at the desktop with them. I think it got to the point that so much was invested in x86 that it was impossible to do anything else, even Microsoft dropped it's NT support for the DEC processor in 1999/2000 refusing to support the Alpha's in Windows 2000 and above.. So we had to wait for AMD to get in the position to prompt the call for 64bit on the desktop..

[Swafe]

the first 64bit was the atari jaguar about 1- years ago , and how **** it was

[Stoo]

It wasn't actually 64bit though..

[Rod911]

Have you seen the PS2's specs? It's got a 128-bit CPU.

[TiG]

Sorry Rod but the only thing I can see there is the 128bit memory interface. we have 256bit memory interfaces on some of the top graphics cards at the moment, and that is generally on the motherboard in terms of DDR memory, apart from the case of the Opteron etc AMD systems where the memory controller is now in the processor.

TiG

[Rod911]

POWER SECTION
At the very heart of PlayStation®2 lies a CPU (Central Processing Unit), that works overtime to command every aspect of the machine. Backed up by the main memory and Graphics Synthesizer, this lets PlayStation®2 push around a phenomenal amount of polygons around your TV screen (which together make up on-screen graphics).

CPU 128 bit custom multi-media Emotion Engine chip:

System Clock Frequency: 294.912 MHz
Cache Memory: Instruction 16KB, Data 8KB + 16KB (ScrP)
Main Memory: 32MB
Memory Bus Bandwidth: 128bit DMA
Co-processor: 2 Parallel Vector Operation Units
Floating Point Performance: 6.2 GFLOPS
3D CG Geometric Transformation: 66 Million Polygons per second
Compressed Image Decoder: MPEG2

[Benjamin]

Sorry Rod but the only thing I can see there is the 128bit memory interface. we have 256bit memory interfaces on some of the top graphics cards at the moment, and that is generally on the motherboard in terms of DDR memory, apart from the case of the Opteron etc AMD systems where the memory controller is now in the processor.

TiG

The PS2's GPU has a 2560-bit memory interface because it's integrated into the chip. Which might explain why the console only needs 4MB of video memory.

[Rythmic]

I'd say the PS/2 needs more - it has terrible texture quality - buts thats just IMHO.

When you're talking buses (a different thing to CPUs, GPUs, etc.) You need to look at bus width (bits) multiplied by the speed (MHz) - the PS/2 video memory is only 16bits (IIRC) but very high speed - typical of RAMBUS.

CPUs are a lot different. First, what do you mean by 16/23/64 bit? The 8088 dealt with 16bit data, but had an 8 bit data bus. Techies refer to the number of bits it can processes internally - but marketeers generally use the biggest number they can (the 640k limit originally came from the 16bit address bus).

To make a CPU cope with 64bit data means adding a lot of extra transistors, decreasing yield. To make a 64bit CPU thats compatible with a 32bit one means adding a ton more - this is why it's taken PCs years to move there (consoles don't have to retain this compatability, so they can move faster - the PS/2 actually contains a coprocessor for running old PS/1 stuff).

The jaguar being 64bit was pure marketing speel - it had 2 32 bit processors. the PS/2 claiming to have a 2560 bit memory interface is another example of this (this would require the bus to have at least 2560 tracks or wires - not happening).

AFAIK the DEC Alpha was the first commercial 64bit chip - there are even 128 bit chips out there, but they're generally considered not worth while, even in Enterprise solutions.

At the end of the day - you have to remember theres a lot of things that go to making up performance - you're not going to see any advantage with 64bit code, if the things you're going to be doing don't use numbers bigger than 32bits. The main reason PCs are heading to 64bit is actually memory size - with a 32bit address bus you can only access 4GB of RAM (due to odd things with windows, 2GB is more the limit - and yes there are ways around this, but none of them are very good).