Supercomputer gaming

[Rakuen Growlithe]

I'm curious, supercomputers can make a few billion calculations a second, I think, which is obviously far more than any normal pc. If you had a supercomputer even without fancy graphics cards would it be able to play high-end games? I doubt there'd be a lack of resources but I don't know exactly how cards and stuff work.

[DesertYote]

It would likely be able to run/process the game, sure, but without the video card it wouldn't display properly (or at all). So yes, the card is needed as part of the processing/storage/display package.

'Yote

[Valerion]

Not really. You get various kinds of applications, some can be massively parallelized,, others not. As an example, finding the sum of all the numbers from 1 to 10 can be done as follows (not very efficient):

CPU1: 1+2
CPU2: 3+4
....
CPU5: 9+10

Then you add up the next 5 numbers on 3 CPUS, the next 3 on 2 CPUs, and the next one on 1 CPU. So you need 4 instruction cycles to do it, if you assume a pipelined architecture.

The problem is that most problems are not like this. Just like you can't add up the second, third or fourth tier without first completing the first one, most problems depend on one calculation to finish before a second one can be begun, and you lose the benefit of massively parallel computing.

In addition, you'll find that you have clusters of CPU cores, linked together by lower-bandwith backplanes that are frequently oversubscribed. This is because each CPU cluster does one parallel thing, and they pass the results between clusters for subsequent steps. And because they are designed to run multiple applications at the same time.

The best application for supercompters are very complex mathematical models, like fluid or air dynamics (weather prediction, for example), or similar types of things. They are so complex that they simply take trillions upon trillions of calculations to complete.

Games traditionally has a single main loop that updates the whole game environment and acts on all inputs, then starts at the top again. Recently this has changed, with people designing multi-threaded games, but even so they do limited threading. And it makes the game orders of magnitude more complex to design. And the resulting code can become non-deterministic (i.e., you cannot accurately predict what it will do under a given set of conditions). That's why true high-performance and absolutely mission-critical code are often written with limited thread pools instead of spawning a thread per job.

On the other paw, graphics rendering IS ideal for this, especially raytracing, as you can do each arbitrary-sized area on its own, as long as you take into account each object in the model. And this is also why your GPU is in essence a massively distributed specialised computing core. It can do certain types of calculations a lot faster than your CPU can.

[Valerion]

It would likely be able to run/process the game, sure, but without the video card it wouldn't display properly (or at all). So yes, the card is needed as part of the processing/storage/display package.

'Yote

Technically it's not needed I remember the days before high-performance GPU's became commonplace (before I got my TNT2), most games could run perfectly in software emulation, using only the CPU. Today Direct3D wouldn't allow it AFAIK, but given sufficient computing power there's no reason you need a GPU. Your CPU can't get a fraction of the speed your GPU can, but that's because your GPU is designed for a single purpose. However, it can still do the job, at a fraction of the speed.

[anoyomouse]

you can force D3D to go to software for most of it's effects, as long as you disable pixel shaders, and vertex shaders, but there are emulators for those included in the DX10 SDK, for people developing next gen games, like the Unreal Engine 3 was developed 90% on those reference software renderers, because there was no hardware to support what they wanted

[DesertYote]

It would likely be able to run/process the game, sure, but without the video card it wouldn't display properly (or at all). So yes, the card is needed as part of the processing/storage/display package.

'Yote

Technically it's not needed I remember the days before high-performance GPU's became commonplace (before I got my TNT2), most games could run perfectly in software emulation, using only the CPU. Today Direct3D wouldn't allow it AFAIK, but given sufficient computing power there's no reason you need a GPU. Your CPU can't get a fraction of the speed your GPU can, but that's because your GPU is designed for a single purpose. However, it can still do the job, at a fraction of the speed.

Yeah, technically. XD I'm just sayin' - if you want it to run properly and at the highest settings, it's pretty much required. I didn't think we were talking forced-software.

'Yote

[Valerion]

Yeah, technically. XD I'm just sayin' - if you want it to run properly and at the highest settings, it's pretty much required. I didn't think we were talking forced-software.

'Yote

True. However, in theory a supercomputer should (?) have the oomph to do everything a GPU does in software mode. It would be interesting to test, though.

The Cray XT5 QC 2.3GHz have 150,152 cores, contructed from 2.3 GHz AMD Opterons. Cray was the traditional leader in the field, and this machine ranks at #2 worldwide.

#1 is a IBM cluster, with 129,600, cores constructed from 1.8GHz AMD Opterons.

If you want more info, go to http://www.top500.org.

Interestingly enough, 424 of the 500 seems to run Linux, with another 27 listing 2 OS's, of which one is Linux. So you should be able to look at the OpenGL games.

[anoyomouse]

OpenGL is horribly single threaded and yeah, is a bitch to multi process.

usually they pack the rendering code into the main loop,a nd go from there.

I want to see a super computer using the new Nehalem intel core
and yeah, linux is the OS of choise, because you have to break it into billions of bits to get it to run properly.

i wouldn't be supprized if each cluster is running a linux, andthen the linuxes talk to each other forming the main body of the PC, there will be a "Main" linux running on the central node that controls the whole thing, prolly realy nasty to work on, but very efficient

[Valerion]

I want to see a super computer using the new Nehalem intel core

Heehee. 60 of the top 500 systems are using AMD x86_64, 9 are using Intel IA-64 and 369 Intel EM64T CPU's. Bear in mind that especially clusters are built from relatively cheap hardware, and still costs millions, so they tend to have a long lifetime. So it always takes a while for the latest to enter the equation, when they are mid- to low-priced CPU's. And clusters like these are not built every day, so we will see when the next big one is done.

Of course, for serious clusters like these you will buy the Opteron and Xeon server versions of the CPU's, not the general-use Athlons and Core-Duo's, for example. Gives you better reliability. For cheap or limited-time clusters you can use whatever is available at the time.

and yeah, linux is the OS of choise, because you have to break it into billions of bits to get it to run properly.

i wouldn't be supprized if each cluster is running a linux, andthen the linuxes talk to each other forming the main body of the PC, there will be a "Main" linux running on the central node that controls the whole thing, prolly realy nasty to work on, but very efficient

*swats the mousey* Now now, don't be nasty But seriously, if you're interested in building your own cluster, there's a LOT of infomation on the net to help. http://lcic.org/computational.html. You can even get specialized distro's to make this easy. And once you've set it up, the entire thing appears as one logical computer. You launch applications at a central workstation, and it automatically migrates the tasks to a system capable of handling the computation (first idle one, I think). It may even break it down for you and send it to various parts of the cluster.

Beowulf (the first such project) was a mission to set up in the mid 90's, but it's gotten much easier these days.

[anoyomouse]

Hehe, i actually want to build a not-so-powerful cluster of old P1 MMX machines i've got lying around/
run then with OpenMosix and see what the systems perform like

[Valerion]

Good luck with building it I'm sure it'll be a fun experience. And let us know how it performs