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Under the Hood of the Xbox 360
An anonymous reader writes "IBM DeveloperWorks is running a behind the design story for the making of the Xbox 360. The 360 has but a single chip with 165 million transistors for it's CPU " From the article: "This chip is in fact a three-way symmetric multiprocessor design. The three PowerPC cores are identical, except that they are physically reflected through the X and Y axis. Each of the CPU cores is a specialized PowerPC chip with a VMX128 extension related to (and partially compatible with) the VMX instructions in the G4 and G5 CPUs. The three CPU cores share a 1MB Level2 cache. Each processor has 32KB each of data and instruction Level1 cache. The chip's front-side bus/physical interface has a 21.6GB/second bandwidth, and runs at 5.4GHz."
Actually, no.
A big cache is good when you are dealing with programs that could access ANY data at ANY time (or you're running multiple programs). With games, that doesn't really happen. Game code is sort of "linear", and you're only running one at a time.. So the cache can be filled with what needs to be there, and nothing else.
Much like Duffman, Sony promises lots of things. There were a lot of features that were supposed to be available on the PS2 that just never ended up in the final system. Not wanting a 360 because it's not that much an improvement over the current XBox is good reasoning. Not wanting a 360 because you just bought a new console a couple of years ago is good reasoning. Not wanting a 360 because of all the things Sony claims will be on the PS3 is just silly. We don't know the "Top 10 reasons for a PS3" because we don't know exactly what the PS3 is yet.
Also, while the Revolution's controller does pose some unique possibilities for gameplay, it's only a controller. Any of the modern gaming consoles could implement such a controller. If it's that big a deal, expect MS and Sony to have their own versions by the end of 2006.
How is it a miracle when this is exactly what's been happening with consoles for many years?
NES looked better than nearly any computer of its day. Ditto Genesis and SNES. Playstation and N64 packed an incredible amount of power into a cheap bundle. Remember the hype about PS2's Emotion Engine? There were rumors that exporting it would be restricted because it was going to be classified as a super computer. People were saying Iraq was going to use it to guide missiles. Xbox literally was a cheap PC, but gave more bang for the buck than your average beige box.
Consoles do this by taking the right shortcuts. They have a very focused performance target for very specific tasks. No need to add anything more than the minimum. Plus, they sell more than nearly any OEM PC maker so they get good prices on the parts.
The global economy is a great thing until you feel it locally.
Anyone who thinks it crashes regularly or that more than 1% of units are overheating is simply a moron. A lot of people here seem to have a fixated fantasy that they are so desperate to believe that they ignore the facts. The fantasy basically consists of that MS has rolled out an overheating worthless machine that when not overheating 95% of the time is crashing. Get real, I'd imagine the failure rates for units are about the same for any piece of consumer electronics.
You forgot the most interesting option...
- The Nintendo Revolution
I don't want to sound like too much of a fanboy, but what can these consoles really give me that my PC can't? I'd rather have a console thats sole focus isn't trying to outpace my PC in terms of graphics... but to push the limits with new controllers, unique games and not costing me my 1st born child or my left arm to acquire.
But mentioning live as the deciding factor is ignoring history. The x-box had it and it didn't sell. Nobody has ever in my opinion come up with a satisfactory reason for the failure of the x-box. The gamecube is easy. It just didn't have the right image. While I thought about 1 or 2 games as worth playing that was it. The rest I considered to cutsey and consoly for my tastes. I don't mind this on my handhelds where it actually helps (don't want to scream like a girl playing fear in public) but not at home.
Another one that amazed me is that one post said the x-box had signed the big names. Bungie and EA. Wtf? Bungie IS NOT a big name. They got 1 game and that is it. EA is big but EA signs on to anything. Getting EA to endorse your new console is like getting a hooker to go out with you for money. Even /.ers should be able to manage that.
The only real advantage that MS has over both Sony and Nintendo that MS doesn't have to win the money race. They can afford to loose money on this generation and the next and the next.
As for the graphics being amazing. Oh please. I already play at higher resolutions on my now 2yr old PC. Richer friends won't accept anything less then 1600x1200 while sony's own games like eq2 can already make use of 512mb video cards despite the fact they were not even out. Other recent games to can make use of hardware features that even top of the range pc's don't have let alone these weak consoles.
I still remember console fans being excited over star fox while I was playing x-wing.
No saying that anyone is going to win the current battle is insanity. The 360 is lacking launch titles and has not got the mindshare with the general public. The PS3 is an unknown quantity and Sony's reputation might be damaged (but this should equally have counted against MS with the X-box) and Nintendo seems to try another gamecube wich didn't work well the first time. The PC (often not counted) has such titles as WoW wich simply cannot run on any of the consoles yet is a huge earner for its parent company. Oh and has all that live crap except at no-charge.
Frankly I find these discussions very amusing but only as an outsider. I remember people defending their console in each of the battles and use the same arguments regardless of the wether they made sense before.
Console fans are like generals. Always willing to fight the last war again regardless of the outcome.
MMO Quests are like orgasms:
You may solo them, I prefer them in a group.
Agreed, the price is a big stopper for some people and, I also agree, there are not a ton of must-have games on the Xbox 360.
:)
However, it does have Perfect Dark: Zero, Project Gotham 3, Kameo (don't knock it 'till you try it) and soon, DOA4 and Battlefield.
Battlefield + Xbox Live = Heaven.
Granted, I don't know a whole lot about what games are coming soon to the Xbox 360 for lack of time, but by the time the Playstation 3 comes out, Xbox 360 will have a lot more games by great developers and I'm going to venture a guess and say the premium system won't cost as much as the PS3 will.
That was my point, was that waiting for a PS3 was stupid. You get less (no unified online service, which is a BIG, BIG portion of why you should get an Xbox 360 over PS3, no titles from Rare or Bungie) and get some things that are somewhat unpleasant (blu-ray: Who really wants a disc format that can brick your system of the manufacturer tells it to? How long before it's cracked and a virus is written? Who really would be angry about getting up every few hours to change a disc? Big deal. None of us had problems with it in the PSX days.)
Just forget for one second that Microsoft makes the Xbox. It's one of the products of theirs I really, really like and is well put-together by a great team.
Go Microsoft?
-Eric Smith
Who wouldn't? Wouldn't you like a 100mb cache? Hell, wouldn't you like all of main ram to actually be as fast as an L2 cache?
This is a game console, not a multi-tasking general purpose PC. This is reflected in both the power a programer has over the hardware, and it is reflected in the fact it depends on the programmer to make up for cost saving measures implemented in the hardware.
You're thinking about thread scheduling the way a general purpose PC would schedule threads. It doesn't work that way in a game system. When talking about threads on a game console, we're talking about hardware threads. The programmer decides what core runs what logic, when it runs that logic; there aren't any context switches, and threads don't "change" cores when running.
The cache design on this chip is actually quite cool. If you're only going to use a piece of data once (or infrequently), you can instruct the processor to not store the data in the L2 cache (leaving data that you're using more freqently in the cache). Additionally, the L1 and L2 cache can hold separate data, and a load into the L1 cache doesn't require a storing that data into the L2 cache. When writing data out to main memory, a program can instruct the processor not to store it in the cache. Software can also reserve chunks of cache for whatever purpose it wants. Finally, a direct link between the CPU and the GPU can be established where the GPU reads data directly off of the L2 cache as the CPU generates it.
These abilitys make it possible to utilize L2 cache better than you would with any general purpose PC. However, it requires more thinking and more effort to do so. That's the price/performance tradeoff you get.
An inability to execute instructions out of order does not prevent PPC code from running, nor is it crippling. Additionally, having an instruction window is rather pointless when instructions can't be executed out of order.
You don't need these things with properly compiled code. But that's the trick; you can't take poorly compiled code and expect it to be performant.
Traditionally general purpose CPU's need the capability to execute out of order because they're running code that wasn't written for their current design -- they have to run code designed to run on x previous iterations of the processor. And traditionally, CPU manufacturers like to tout how their new processor runs x benchmark 50 times faster -- and they can't do that without out of order execution.