PS3 Cell Chip: SPE's each have Atomic Cache

Games developer Dean Calver, currently working as lead programmer for Ninja Theory on Heavenly Sword for the PS3, has posted an interesting article about programming for the PS3's Cell chip.

"Atomic Cache Unit. Never heard of it right?

Well its one of my favorite things on the PS3 and gets little love cos its one of those tiny features that make life so much nicer.

Atomic ops refer to the most important principle in multi threading. It say that a single processor must read/modify/write without another thread interrupting (hence atomic). Without atomicy, multiple core system are much harder (if not near impossible)

The ACU (s) are a part of each SPU that allow atomic updates to occur very quickly. It appears fairly simple each SPU had 512 bytes of cache (yes contrary to what you might have heard SPU do have a tiny bit of cache). 512 bytes is divided into 4 128 byte lines. The MFC (DMA) unit can bring a cache line in from memory and mark it reserved… if another processor writes to the same bit of memory the reservation is lost and you know to repeat the read/modify/write cycle to guarantee atomicy.

All good, but whats really clever its how its implemented. If another SPU asks for that bit of memory its get its from another SPUs cache, if its in there. So you effectively have a fast SHARED 512 bytes. When an SPU writes, the other SPU only have to read from the writing SPU cache rather than DMAing it back to main memory and DMAing it into LS. Cuts down alot of memory traffic. I even abuse it and just use it as a conventional cache and communication channel between SPU. You can push alot of data around with a fast 128 byte path."

[techie]

dang you linked to his blog. Deano's coming into fame.

[THE TRUTH]

For the editing, I have been away from the site for about 6 months don't worry I will get it right from now on ^.^ enjoy

[THE TRUTH]

It's amzing how much info is STILL coming out regarding the Cell Chip, it's just amazing technology

[sandip787]

wow truth, where have you been? i remember reading your stuff ages ago!

[neogeo]

that makes him super smart, And that makes our game super sweet!

[closedxxx]

"Well its one of my favorite things on the PS3 and gets little love cos its one of those tiny features that make life so much nicer."

It gets no love because it makes life so much nicer???

If something makes my life nicer, I give it love.
I doubt the reason it gets no love is "because its one of those tiny features that make life so much nicer.

I believe a language barrier is to blame

[techie]

It was a quick article for Deano for his private blog, wasn't meant to public publication.

[nix]

i guess it means little bit more... or little more attention. q:

[JCDenton]

Why is this article on N4G.com? Why would gamers give a damn how hard/easy is to program for one platform. That's developers concern. Or is this another almighty-cell-in-PS3-will-blow -away-everything-on-every-othe r -console-because-it's-limitles s flamebait?

[techie]

JC I feel the same...because it doesn't make much sense to me. BUT you'd be surprised how many of the members on n4g are developers... plus there is a "dev news" section.

[THE TRUTH]

Why is this article on N4G.com? It's just information on the Cell Chip from a developer blog, I don't see the reason to throw a tantrum over it. Especially when we have "NEWS" posted comparing Halo 3 and R:FOM.

I thought some gamers would be interested, I'm sorry if I was wrong maybe I should just stay away from this site.............

[Armyless]

This article is exactly what should appear in N4G, it's why I come here... for information. I'm fascinated by the inner-engineering of my PS3 GAMING CONSOLE.

The fact that this bothers anyone is a mystery to me.

[Bathyj]

So fanboys can spout nonsense about how hard PS3 is to develope for based mostly on their irrational hate of the machine, but actually information from a dev who knows what he's doing shouldn't be posted?
Dont FKN read it if you dont like it.

[ShAkKa]

but it seem that when some peoples see something they dont like they always try to find something to bash it

[nix]

no more stupid excuses... ok? kapish? q:

[Bathyj]

If a team the size of Media Molicule can get results I dont see why EA cant.

I think the trick is not to think like traditional PC or Xbox hardware. Its not hard, its just different. If you want the best out of PS3, focus on the PS3.

[Odion]

This isn't new information on the cell, its not like they just found this thing, its just that there aren't entire aticles on every part of a processor, cause most people wouldn't find it to be information thats important to their gaming experience.

[THE TRUTH]

I apologize if it doesn't interest you............ Funny how when I was posting this I forseen a much different reaction from the "gamers" on this site.

[Adriokor]

If you are not interested in the article don t read it or at least keep your everyday negativty to yourself.

Let people who actually like the news enjoy their readings.

Truth, there is a lot of kids and fanboys on the site, don t mind them.

[Mr Playboy]

Thanks

[THE TRUTH]

Thank you ^.^
Adriokor and Mr Playboy

for the kind comments, there may indeed be some hope for this site.
GAME ON

Oh and if you read his comment section you find a few nice points of interest like

720p 4xAA at 30fps is our stated aim

Release date is set by Sony… Its fairly soon and are working our butts off to make it as good as we can by that date. Hopefully various bugs and things like abrupt transitions and FPS will be smoothed out by then.

and

Comment by Deano — May 23, 2007 @ 4:03 pm

Its a bit of both… Depends on the demo and other things. For example for E3 2005 and 2006 the main team did the work and essentially worked 100% on polishing and making it fit for viewing by the public.
However if you take the PSN demo we are currently doing, then we have a separate team (borrowed from Sony Cambridge) who are doing the work to make it a stand alone demo while the NT team are working on Beta. There’s still work for the main team fixing bugs and balancing but its much less than full time.

and

Balancing a game like HS isn’t easy…

As a counter point I know of at least two bugs in the bug db that without a cheat its impossible to complete some sections

Theres a formation system that tell the enemies when to attack and what ‘grombo’ (group combo move) to do. That has simply been turned way down for the demo’s I suspect.

By the time it ships it should be the right level of difficulty.

Comment by Deano — May 22, 2007 @ 6:00 pm

Your hear lots more about Kai soon enough I expect.

You should only see ‘loading’ at the beginning of a chapter, all the rest is async loaded in the background. Of course ironing out the stutters and load pauses is one of the things we are working on at the moment.

enjoy

*** Demo coming real soon ***

[Why o why]

Dont let the negs stop you from spreading the pos

[JCDenton]

I'm not saying this article isn't interesting, on the contrary. But, you know how people act around here, and misuse/abuse everything they can to either praise one gaming system, or to bash it.

Second, I'm not "a kid" or "a fanboy" like someone said...

[sajj316]

Back to my PS3 programming ... atomic cache, here I come!

[nix]

there are more sane people here than one might think.. don't worry most people will appreciate your effort. ((:

[VaeVictus]

I too find this blog interesting. Disregard the negative statements as there are those of us out there that do not wear blinders and are fascinated by things like this.

Cool stuff.

[InMyOpinion]

Blah blah blah. The more of these articles I read about how wonderful the Ps3's architecture is, the more I realize they write them to cover up the fact that it has no interesting games. The ones that are interesting get delayed. Probably cause the Ps3's development kits are dreadful to work with. What other reason could there be to all the delays? Even games like Dirt, that have engines developed in collaboration with Sony, with the Ps3's architecture in consideration, get delayed. To me (you don't have to agree and I guess you won't) it all seems like desperate attempts to resuscitate something that has been dead since birth. Playstation? Nah, Displaystation is more like it.

I'll not satisfied until I get at least 4-5 "Just-you-wait" replies. It will do this, it will do that! lol!

[Why o why]

your comments oooze negativity. do i need to tell you that your name is jenzo???? or that night turns to day? or that there are not that many "aaa" games out for the ps3? or that there are not too many games out for the 360 neither. My point is that you dont need to tell us what we already know. Im looking for the future and its bright. im sure we'll be happy for years to come. Theres nothing wrong with a little bit of positive news and im not fooled or have been made to forget that theres not enough good games out now and not just for the ps3 but 360 and wii.

Wheres your great games?

Huh?

Edit you have about 2 minutes left bub

[kewlkat007]

Thanks for the Article "Truth" but this is probably old news. Unless they just discovered after a year + the cell has "atomic cache." Which I doubt.

The PS3 has been out bro, the Cells Bell and whistles have already been "shrimp on the barbie". on N4G.

So what else is new?? besides not having games..to showcase all this jibber jabber numbers. Thanks for the Atomic Cache tho.

[Armyless]

Keep up the good work!

[etnuhc]

It is not often that an article on the Cell or how developers go around making the programs that they do. I'll be checking out Deano's blog and read his past articles now.

[Cartesian3D]

I love these kind of tech articles.. even it come from a blog..

I was searching for cell structure before Ps3 release.. and find some pdf from IBM that contains full describtion of cell..

really good job many new info was there.. :)

[deadeyes99]

So where is this performance shown? How long will this prelude to "THE TRUE POWER OF THE PS3" be ongoing? I don't see any outstanding difference from 360, in fact most of the time the 360 has better visuals and it costs a few hundred less, and who are they to dish out that kind of a price tag for something we can't fully use it's just unjustifiable and until i see actual results like ps3 keeping way higher frame rates, better AA this info is nothing but talk, im only speaking the truth so make of it what you will.

[Armyless]

-

[StateofMind]

Thanks for telling us the "truth" deadeyes99, but I'm more inclined to believe what the developer of Heavenly Sword has to say about programming than you. Sorry.

[techie]

The game he's working on isn't out yet.

ps. he doesn't say anything about being superiour. He talks about this feature he has found.

[sak500]

Maybe now some rogue leader like Saddam will order thousands of ps3s so they can make missle launchers. Poor sad-dam also believed sony hype for ps2 and ordered thousands and thousands of ps2s to use them for military purpose.

There you go sony fannies, take the 2nd last bubble as well.

[HaKeRsCanRotINHEL]

but useful none the less. 8~B

[ApocalypseShadow]

but thanks anyway truth.you have to understand,while you were gone,there has been an increase of negativity from some 360 gamers because ps3 is starting to come into it's own groove.

f@ck them and continue your news postings.

[Close_Second]

...I'm running out and buying a PS3 right now because of this. Hell, why doesn't Sony stick "Atomic Level Caching" on the box so everyday consumers can feel even better about their purchase.

Who cares!!! stop bleating about the hardware and start putting it to good use. Everyone keeps saying its leaps and bounds ahead of the competition (with a price to match) and yet we still don't see it in the games!!!!!!!!!! Stop selling "potential" and start giving us the reality!

[VirtualGamer]

If your not interested in hearing about this then simply skip it. I certainly don't read or check out every news posting on the site, only the ones that interest me.

I have a feeling your motivation for commenting goes alot deeper then simply that you don't care. Remember Gears of War took developers a year after the 360 was released to show its true power and its suppost to be easier to program for and has better support. When the PS3 has been out a year and games don't look any better then you might have something to actually complain about.

You know the funny thing is that in the 6 months since Gears of War has been release not a single game for the 360 has come out that is equal or better graphically? What's up with that?

[kewlkat007]

sorry to burt your bubble "not every DEVELOPER is created EQUAL"

Not every game will look like GEARS.

Thanks to GEARS for raising the BAR but its like EXPECTING MARIO to have GEARS GRAPHICS, ehh just wouldn't look right. Every developer uses different engines and have their work cut out for them with whatever games they may come up with. I don't see all PS3 games looking like Motorstorm either, well really I don't expect them to.

The 360 does have so great looking games, probally jsut not up to your standards or quite on par with Gear of War developers EPIC. The 360 has enough memory to make games look great over time or should I say when developers of all kinds really optimize, its strengths, just as the PS3. EPIC jsut ha d amaster piece early on, and that Unreal Engine is no slouch.

Then again when was a game all about graphics, can't you just enjoy the games or are you still waiting for some?

[VirtualGamer]

I love the games I play on my PS3. RFoM, Motorstorm and VF5 are not only great looking games but play great as well. I realize not all developers are equal but its funny how when a developer says something positive about programing for the PS3 we get comments like Close Second's.

Games like Ninja Gaiden Sigma, Lair, HS, Uncharted, R&C, etc are definately showing the power of the PS3 not only in graphics but in game play as well and its only the beginning. I am also not silly enough to think that the 360 is not going to have more great games coming as well. All I was trying to point out was that only one developer so far has been able to tap into the power of the 360 and no one in 6 months after has yet to do the same. It also took Epic a year after the 360 was released before they came out with Gears. This from a console that's so much easier to program for and has better development tools. So again is it any wonder it has taken PS3 developers some time to get a handle on things and even the ones who have are saying they have barely started to take advantage of what the SPU's are capable of. As a PS3 owner I look forward to seeing what they can do in the years ahead and articles like this that help explain how they are and what they have figured out. To me thats is a good thing but for some it seems like its a bad thing and they use it to bash Sony, the PS3, the developers for blogging about it and then for someone to submit it as news. Again if your not into this kind of news, "SKIP IT" rather then complain.

[TylerDurden]

Considering that the Cell is constantly under attack(by myself as well), information like this is definitely good to see on this site.

As a dev (non game programmer though) I fail to see the benefit in this. I thought not having to use cache lines was a benefit of the Cell processor. Also any multithreaded language has atomicy/thread synchronization support that is provided to the developer.

Of course since I have never written an application that targeted the cell processor I am sure this dev's word is a lot better than mine on this subject.

[THWIP]

"Oh and if you read his comment section you find a few nice points of interest like

720p 4xAA at 30fps is our stated aim

Release date is set by Sony… Its fairly soon and are working our butts off to make it as good as we can by that date. Hopefully various bugs and things like abrupt transitions and FPS will be smoothed out by then"

You DO realize that 720p and 30fps is really nominal....particularly for the "mighty PS3", don't you? If that's the best they can hope for....something that's an industry minimum standard....then this opinion piece holds ZERO value. :o

[techie]

".then this opinion piece holds ZERO value"

Go home tham. This guy is a programmer, it's not an opinion...it's what he has discovered. You didnt read it, and if you did, you didn't understand it. HS is doing HDR and 4xAA, 8xAF, has been listed as 720p for 3 years, and a locked 30fps is perfect for the game. SO back off tham.

[gta_cb]

good read

[gta_cb]

nad whats more seems to be no flamewar.

[StateofMind]

This is definitely an interesting read, thanks for posting.