Boffin stacks 16 PS3s to simulate black hole collisions
Consoles for cosmology
When most of us arrived home with our newly purchased PS3, we couldn't wait to start annihilating aliens in Resistance: Fall of Man or kicking butt kung fu-style in Virtua Fighter 5. Not astrophysicist Gaurav Khanna - he used his to build a supercomputer.
Khanna now owns a total of 16 PS3 consoles, all linked together to provide the same computing power as a 400-node supercomputer. His set up, which he calls a 'gravity grid', is used to simulate the activity of very large black holes for the Physics Department at the University of Massachusetts.
Stacked Sonies: the 'gravity grid' set up
The project is an attempt to estimate the properties of gravity waves generated by the collision of two black holes. Gravitational waves are 'ripples' in space-time that travel at the speed of light. These were theoretically predicted by Einstein's general relativity, but have never been directly observed.
In order to run his simulation data on the consoles, Khanna had to load the PS3s with Linux. What makes the gaming console more effective than high-end computers for complex research algorithms is the Cell chip built by IBM to process high-end gaming functions.
Linux powered
"Linux can turn any system into a general-purpose computer, but for it to work for me I have to run my own code on it for astrophysics applications. The hard part of the job was to make sure my own calculations could run fast on the platform, which meant I had to optimise the written code so it could utilise the new features of the system."
The 16 PS3s haven't been physically modified. They're networked together using an inexpensive Gigabit Ethernet switch.
"Overall, a single PS3 performs better than the highest-end desktops available and compares to as many as 25 nodes of an IBM Blue Gene supercomputer," Khanna noted.
More details from Khanna's project site here.
COMMENTS
@Highlander
Highlander believes that if the Cell processor is upgraded in the PS4 then the upgrade will be to clock the Cell processor at a higher frequency and not to increase the number of SPEs. I think that this is unlikely. This is because I understand that doubling the clock frequency of a processor increases the power consumed by a factor of four.
A far better use of that extra power would be to quadruple the number of transistors in the Cell processor chip. This is the approach that intel has take with Core Duo processors where extra performance in gained by increasing the number of processors on the chip and not by increasing the clock frequency.
I extimate that quadruping the number of transistors in the Cell processors chip would increase the number of SPEs from 7/8 to around 40.
According to Moore's law the number of transistors on a chip doubles every 18 months. It is therefore perfectly possible to imagine a Cell processor with 40 SPEs being available 3 years after the manufacture of the original Cell processor.
IBM Cell processor documentation does not specify the number of SPEs which indicates that future Cell processors will most probably include more SPEs.
@ ex-Applenazi
Quote: "But can anyone finally please explain to me why Wii-games cost EXACTLY the same as PS3- and X360-Games then?"
I dunno where you buy your games, but Wii games tend to be 10-20 EUR cheaper than PS3 or Xbox games.
Oh, if I were you I'd get a new keyboard. Yours is dropping smilies and exclamation marks all over the place. It makes you look like a bit of a d!ck...
Joe Cooper:
"If developers are going to try to target multiple platforms, that will only make it less likely that a bizarre architecture will be utilized effectively."
Lucasarts just announced they'll develop Games for PS3 first and then downport them to X360, didn't you hear?
http://ps3forums.com/showthread.php?t=124972
Which is just another sign that the X360 is going down the drain.. Especially now that the HD-wars are over and BD has won, and that RROD-disaster is *still* going on.. Oh, btw: PS3 has just passed the X360 worldwide minus America -> www.vgchartz.com
Wii passed them long ago, and PS3-Market share keeps growing slowly but steadily! ;-)
Also, there are finally some really good games already out or coming really soon: Burnout Paradise, Motostorm, Uncharted, Resistance, UT3, CoD4 (already here), LittleBigPlanet, Killzone2, GT5 (coming soon)
Okay, Lair and Heavenly Sword weren't as good as expected, and Assassins Creed was merely good, but well, it won't kill the platform! ;-)
And while it may be fun, the Wii isn't included in the regular crossplatform development plans anyway (just not possible, it would "drag down" the graphical quality for the other systems too much!), due to a way different control scheme, target group and hardware that's too weak. Mind you, it's not too weak for fun games, and I'm not saying there won't be great games for it, they'll just be different games than the regular x-platform titles. If that's an advantage or disadvantage remains to be seen, but here this question is irrelevant! ;-)
"You can't really brush this off by saying graphics aren't important because if graphics aren't important, than the Playstation 3 has no competitive advantage against the cheaper to buy, cheaper to develop for Nintendo Wii or X-Box 360."
Gee, i keep hearing this about the cheaper-to develop-for Wii (not X360, when they say this game studios mean primarily content generation, and that is *exactly* as work-intensive as for PC or PS3!). But can anyone finally please explain to me why Wii-games cost EXACTLY the same as PS3- and X360-Games then? What happened to all that "easier to develop, so games will be cheaper"? Is Nintendo raking in all the extra money?
It's a bit like this whole "HD-DVD is way cheaper to produce because we can use DVD-manufacturing lines" BS - Where exactly were HDDVDs cheaper than BDs?
@Highlander
Yes, I should probably have mentioned that even the official Sony docs suggest that you avoid using that painfully small bandwidth from the CPU to the RSX's memory, and get the RSX to write the data to main memory where the CPU can read it at the normal (very, very quick) speed.
Although, this is discussing the specific case of trying to use RSX memory when the CPU memory pool is already full - at which point there isn't much space to do such a thing. A small 'paging' area would work, somewhat like the old memory pages on the 128k Spectrum, if you're elderly enough to remember working on that.
I don't know the guy's application code, but it might well be that 256Mb is enough anyway. There are plenty of clever things you can do in that space, without needing any more.
@J
"Probably not "typical desktop Linux" at all, eh?"
Of course not!!
But several people here brought up performance under various circumstances including desktop. I wanted to explain that it's not designed for such a workload, but it's fantastically fast floating point abilities make it fantastically well suited to other workloads.
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The comments that it's not suited for games are just dumb. The PS3 is easily the most powerful of the game consoles, even if it's power hasn't been fully realized.
Note that this is different from saying "The PS3 is the winner". In the last two generations of game consoles, the top spec system sold the worst and the lower specced PSX and PS2 kicked ass on the market.
The PS3 is reminding me of a lot of systems, none of them winners on the market.
The Sega Saturn, for example, also had fantastic processing power in a bizarre architecture that would require special investment to take advantage of.
The Apple Pippin too. It was more PC like, and had the same sort of ill-conceived banana controllers that often go with really expensive systems that do things nobody really cares about. (Sony did dump those banana controllers though.)
If developers are going to try to target multiple platforms, that will only make it less likely that a bizarre architecture will be utilized effectively.
You can't really brush this off by saying graphics aren't important because if graphics aren't important, than the Playstation 3 has no competitive advantage against the cheaper to buy, cheaper to develop for Nintendo Wii or X-Box 360.
