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Intel Reveals More Larrabee Architecture Details
Ninjakicks writes "Intel is presenting a paper at the SIGGRAPH 2008 industry conference in
Los Angeles on Aug. 12 that describes features and capabilities of its
first-ever forthcoming many-core architecture, codenamed Larrabee.
Details unveiled in the SIGGRAPH paper include a new approach to the
software rendering 3-D pipeline, a many-core programming model and
performance analysis for several applications. Initial product
implementations of the Larrabee architecture will target discrete graphics
applications, support DirectX and OpenGL, and run existing games and programs.
Additionally, a broad potential range of highly parallel applications including
scientific and engineering software will benefit from the Larrabee native C/C++
programming model."
With the supposed death of Usenet, the closing of PARC, and the general Facebookification of the Internet, its nice to see a bunch of nerds get together and geek out simply for the sake of it.
I want to delete my account but Slashdot doesn't allow it.
With more and more emphasis going toward GPUs and other specialized processors, I wonder if this is to try to fight that trend and have Intel processors able to handle the whole computer again.
This is good news for Mac mini and MacBook users.
How so? Has Apple announced that it will adopt Larrabee for the Mac Mini or the MacBook? No. All you have are rumors and speculation by MacRumors and Ars Technica. When Apple says they will adopt the Larrabee GPU, then you can say that it is good news for Mac users of any stripe. Until then, it's just Intel news, not Apple news.
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This is good news for Mac mini and MacBook users. But I can't stand them.
Fuck systemd. Fuck Redhat. Fuck Soylent, too. Wait, scratch the last one.
I think it depends on how much Larrabee will cost, however with what we know so far Apple seems to be heading into multi-CPU architectures, so using Larrabee would make sense.
Larrabee costs somewhere between 150 and 300 Watt, so MacBooks and Mac Minis are not likely to use them. Mac Pro, on the other hand, possibly.
No, because the article is about Intel explaining that the purpose of Larrabee is NOT to be specialised like that. It's meant to be a completely programmable architecture that you can use for rasterization, ray tracing, folding, superPi or whatever else you want to program onto it.
Basically, they're trying to say "it's not REALLY a GPU as such, it's actually a really fat, very parallel processor. But you can use it as a GPU if you really want to".
It almost certainly won't work. In the past, there has been a swing between general and special purpose hardware. General purpose is cheaper, special purpose is faster. When general purpose catches up with 'fast enough' then the special purpose dies. The difference now is that 'cheap' doesn't just mean 'low cost' it also means 'low power consumption,' and special-purpose hardware is always lower power than general-purpose hardware used for the same purpose (and can be turned off completely when not in use).
If you look at something like TI's ARM cores, they have a fairly simple CPU and a whole load of specialist DSPs and DSP-like parts that can be turned on and off independently.
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Is it not also good news for Windows users, Linux users, and *BSD users? I mean, it's likely that these OSes will also be made to make use of Larrabee when the technology is released, right? Yet, it's not news for any of those platforms or Apple users unless/until those platforms are able to make use of the new GPU technology. Everything else is just speculation, especially so for Apple, who might easily decide not use Larrabee. Since Apple is the only legit supplier of Mac OS X hardware, it's definitely not news for Apple users until Apple says it is. OTOH, Windows, Linux and *BSD users can get their hardware from any supplier.
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The Quake engine uses OpenGL (or its own software renderer, but I doubt anyone uses that anymore), so games based on it do use OpenGL. Most open source games that use 3D use it, as do most OS X games, and quite a lot of console games. OpenGL ES is supported on most modern mobile phone handsets (all Symbian handsets, the iPhone and Android) and the PS3. I don't know why you'd think OpenGL was dead or dying - it's basically the only way of writing portable 3D code that you want to benefit from hardware acceleration at the moment.
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I don't think so. I think the fact is that with the right architecture (which Intel is trying to get into place) which exact core on which processor handles a specific task should become less and less relevant.
What this technology will hopefully provide will be the ability to have a more flexible machine which can task cores for graphics, then re-task them for other needs as they come up. Your serious gamers and rendering heads will still have high end graphics cards, but this would allow more flexibility for the "generic" business build PC's.
I'm a fiscal conservative, it's a pity we don't have a political party anymore
I think Larrabee is quite believable. They are quoting performance number that make sense and a power consumption of 300W. The only unbelievable idea is that a component that draws 300W is a mass-market part in an era when computers that draw over 100W total are increasingly uncommon and handhelds (including mobile phones) are the majority of all computer sales with laptops coming in second and desktops third.
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It almost certainly won't work. In the past, there has been a swing between general and special purpose hardware.
Except with unified shaders and earlier variations the GPU isn't that "special purpose" anymore. It's basicly an array of very small processors that individually are fairly general. Sure, they won't be CPUs, but I wouldn't be surprised if Intel could specialize their CPUs and make them into a competitive GPU. At the very least, good enough to eat a serious chunk upwards in the graphics market, as they're already big on integrated graphics.
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Isn't the point of Larabee to change that? With umpteen Pentium-compatible cores, each one beefed up with vector processing instructions, software rendering might become fashionable again.
-- Ed Avis ed@membled.com
Today at a coder's party we had a discussion about Intel's miserable corporate communications.
Intel's introduction of "Larrabee" is an example. Where will it be used? Only in high-end gaming computers and graphics workstations? Will Larrabee provide video adapters for mid-range business desktop computers?
I'm not the only one who thinks Intel has done a terrible job communicating about Larrabee. See the ArsTechnica article, Clearing up the confusion over Intel's Larrabee. Quote: "When Intel's Pat Gelsinger finally acknowledged the existence of Larrabee at last week's IDF, he didn't exactly clear up very much about the project. In fact, some of his comments left close Larrabee-watchers more confused about the scope and nature of the project than ever before."
The Wikipedia entry about Larrabee is somewhat helpful. But I don't see anything which would help me understand the cost of the low-end Larrabee projects.
You still need an API - which OpenGL provides. On the hardware side of things, few chips actually implement the (idealized) state machine that OpenGL specifies, it's always a driver in between that translates the OpenGL model to the chip model.
Your comment, "... as they're already big on integrated graphics." is true for some values of "big". Intel has been big in integrated graphics the way a dead whale is big on the beach.
Basically, once you discover what Intel graphics has not been able to do, you buy an ATI or Nvidia graphics card.
The power brick for my Core 2 Duo Mac mini is somewhere around 80 Watts I think. And I'd assume the actual usage is lower than that. Let's say 50~60 Watts for the whole computer (CPU, GPU, hard drive, optical drive, RAM, FireWire, USB, etc).
If Larrabee takes 150~300 Watts, then it's just insane, no matter how many cores it has.
What most people don't seem to realize is that Larabee is not about winning the 3d performance crown. Rather, it is an attempt to change the playground: you aren't buying a 3d card for games. You are buying a "PC accelerator" that can do physics, video, 3d sound, dolby decoding/encoding etc. Instead of just having SSE/MMX on chip, you now get a complete separate chip. AMD and NVIDIA already try to do this with their respective efforts (CUDA etc), but Larabee will be much more programmable and will really pwn for massively parallel tasks. Furthermore, you can plug in as many Larabees as you want, no need for SLI/crossfire. You just add cores/chip like we now add memory.
P.
> so far it looks like the x86 version of Cell
Then you missed the fact that the article says it uses a coherent 2-level cache for inter-core communications; the Cell BE is quite exotic in that it uses DMA transfers and has no memory coherency between the SPEs.
The article doesn't explicitly state that the Larrabee cores are homogeneous, but I would be surprised if they weren't; the Cell cores are somewhat heterogeneous if you want to use the PowerPC core to squeeze the last drop of processing power out of it.
You are correct in that Intel appears to have copied the ring network of the Cell BE, although I don't understand why they need it in addition to the coherent cache. Oh, well, guess I'll have to wait until the paper really hits the public.
OpenGL is just an abstraction layer. Mesa implements OpenGL entirely in software. Implementing it 'in hardware' doesn't really mean 'in hardware' either, it means implementing it in software for a coprocessor that has an instruction set better suited to graphical operations than the host machine.
Sure, you could write your own rasteriser for Larrabee, but it wouldn't make sense to do so. If you use an off-the-shelf one then a lot more people are likely to be working on optimising it. And if you're implementing an off-the-shelf rasteriser, then implementing an open specification like OpenGL for the API makes more sense than making everyone learn a new one, and means that there's already a load of code out there that can make use of it.
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That is much more detailed than the one linked in the article summary. It can be found here.
This is SIGGRAPH. They've been having the 'ray tracing versus rasterisation' debate for about three decades there. If you put anything definitive into your paper then you are likely to get a reviewer who is in the other camp, and get your paper rejected. If you say 'speeds up all graphics techniques and even some non-graphics ones' then all of your reviewers will be happy.
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One language that is being used in the sceintific community right now is CUDA - which runs on a GPU and is C based.
In addition, Fortran to C tools have been around for some years. To say that Fortran is the only scientific language is BS. R, S Plus, Octave, matlab, perl and CUDA to name a few. Taking R as an example - it provides an code interface that allows you to write optimised C/C++ routines and utilise those in the language itself.
And once you discover what kind of driver support they offer, you go right back to Intel.
The new Intel G45 chipset recently made me order a new motherboard just to replace my video card. It's "fast enough", one might say...
Personally, I can't wait to get all that proprietary crap out of my kernel. Shouldn't have fallen for the temptation in the first place.
My Sig: SEGV
They've stated that it will be a 150W+ chip on a PCI Express 2 card, as I recall, and is intended as a GPU, though it will be fully programmable and have CPU capability (so when not doing GPU stuff, it could serve as extra CPUs). It is intended to compete in the high end graphics market.
Essentially, it's a clutch of high performance software vector units in parallel with a bunch of CPUs. Graphics scale with each added processor because it is a software driven architecture, whereas traditional GPUs don't scale because they have a fixed function pipeline (if everything were written for shaders, I would think it would scale). One of the things Intel is touting is Binned rendering (aka chunked or tile rendering), which is breaking the frame into tiles and storing a list of front-to-back polygons in off-chip memory and the tile buffer is scaled to cache. Technically, this should be no faster than z-buffering, but I believe they're sorting and ray casting and in a brute-force sort of way this is faster than z-buffering. What I don't get here is how they get "2-7x the performance" because they have the extra sort step.
By the way, if you look at CPUs, Intel's Core2 line has five power designations:
X - Extreme - power > 75W
E - Standard Desktop 55-75W
T - Standard Mobile 25-55W
L - Low Voltage 15-25W (their name - they mean low power)
U - Ultra Low Voltage - Power < 15W
According to Wikipedia the mini uses mobile processors (the T designation). Max power consumption of most laptops is 80W, so it is likely your mini maxes at 80W.