Jon spends much more time looking at CAGRs, IHV marketing decks and sales projections than I do, but having read the report I do wonder if he’s missed a trick or two while staring at his tea leaves. Reading the report it’s clear that JPR’s remit was to explore multi-GPU from the perspective of scaling the graphics performance by using multi-AIB and multi-GPU systems. Not too surprising given that the report was at least partially sponsored by LucidLogix and to a lesser extent AMD and NVIDIA.

As an aside, LucidLogix are an interesting entrant into the graphics market, as they are producing an IHV agnostic chip that potentially allows for multi-GPU scaling to take a very interesting turn indeed. It’s not clear yet how their product will be greeted by the market (or indeed the IHVs), but if it works as well as they say it does (and I haven’t seen it in action yet) it has the potential to break the current state of single vendor (and mostly single device variant) multi-GPU systems (SLI vs Crossfire).It also has the ability to give habitual AIB buyers a far longer working life for their previous purchases, as in theory, a motherboard enhanced with a LucidLogix device means you can run your latest GPU in parallel with your previous primary graphics card.

ATI/AMD promised this a while back but I’m not sure it was ever delivered in any meaningful way (they were promoting it as a potential route for physics acceleration around the time NVIDIA acquired PhysX) and NVIDIA have shown systems where an NVIDIA IGP and an NVIDIA AIB co-exist and the driver selects the most appropriate device for a given workload (Hybrid SLI). With a LucidLogix Hydra device acting as a bridge, the theory is that the user sees something approaching additive scaling (certainly not a given from existing solutions) from a mix of different GPUs and best of all you won’t necessarily be tied to a single vendor either. Of course there’s likely to be a very long list of caveats to achieving this multi-GPU nirvana but that’s another (very interesting) blog entry and I digress.

My immediate thought while reading the JPR report was that the analysis curiously excluded IGPs (Integrated Graphics Processors) and thus I presume, devices coming from AMD and Intel with graphics integrated into the same package as the CPU (e.g. Fusion from AMD). The current trend to integrate graphics on the CPU package is a cost driven evolution from North Bridge IGPs (memory controllers already having moved to the CPU), with both AMD and Intel wanting to leverage their position as ‘platform’ vendors, and to offer price reductions to PC OEMs (but coincidentally increase the proportion of the PC’s BOM they see).

In terms of the number of people who only ever see an integrated graphics solution in action (be it in the chipset or in the future next to the CPU) we’re probably approaching 50%, given Intel’s current dominance in the mobile and mid to low cost desktop markets. If AMD’s Fusion range succeeds it will mostly likely take market share away from Intel rather than the AIB market. So this suggests one way in which JPR sees the market evolving, but apart from the continuing drive to improve rendering performance he doesn’t really offer any other market drivers. Should he have?

In recent years what has driven the evolution of the PC and the growth of the GPU vendors, has really been games. THis isn’t going to stop any time soon (even with consoles accounting for an increasing proportion of that market). At the same time the move to use COTS (Commercial Off The Shelf) systems in HPC (High Performance Compute) has also been a significant evolutionary driver for x86 as a platform.

So where does that leave this new wave of heterogeneous compute that the GPU vendors are so keen to exploite these days? Speaking as a person who already works with heterogeneous systems (i.e. accelerated using GPUs and other specialist co-processors) to solve engineering and scientific problems for clients, the quest for better performance for ISV (and custom) codes will drive adoption of in the personal workstation market, but that still leaves the consumer side of the equation.

This is where being involved in the Khronos Group and watching the evolution of OpenCL from the inside, has shown me just how wide a reach OpenCL (and other related APIs) potentially could have. It won’t just affect the software we write but it also has the potential to shape the direction that the future of PC architecture will take and ultimately this is bound up with the software that we run on them. This leads me back to my cause and effect observation: Just what would drive 50% of all PC owners by 2012 to have bought at least one additional AIB (or bought a machine that shipped with two AIBs)?

We have already seen that the market wasn’t quite ready for a single source, vendor specific and cost option as far as physics acceleration was concerned. This is not to say that PhysX has been a failure, but it’s not currently achieved the market penetration to really drive sales of NVIDIA AIBs in its own right. AMD have lately played smart, and offered a potential counter to the PhysX marketing bullet point that also addresses the issue of vendor specific solutions, by porting the Intel owned Havok physics engine to OpenCL (an interesting move in itself from a marketing perspective).

All of this leads to more questions than answers at the moment. Will the relatively recent existence of an open, cross platform and most importantly cross vendor programming target in OpenCL feed the growth of a non-game based software ecosystem, that is not just able to take advantage of heterogeneous acceleration, but will actually drive it in some quite remarkable directions? Will OpenCL be able to meet the Microsoft juggernaut (in the form of DirectX11 Compute shaders) head on?

I actually think these two approaches to tapping the compute horsepower available from GPUs are actually complementary rather than necessarily in direct opposition. DX11 Compute Shaders (and their evolutionary descendants) will undoubtedly enable performance improvements for games and open up a wealth of new options for game developers, but I think the smart money for ISVs wanting to develop other applications for heterogeneous systems will be with OpenCL. When the OpenCL standard matures a little and the IHVs work out some of the current interoperability issues, we will start to see truly heterogeneous software solutions arrive and this, I think, could be really important. A healthy software ecosystem will sustain, though it may not significantly grow the current AIB market (much as JPR predicts), but a lot still depends on where the gamers end up because at the moment this is what’s driving the year on year improvement in GPU performance.

As luck would have it Neil Trevett, the Khronos Group President, and incidentally an NVIDIA VP, has an interesting interview on The TechReport today along these lines.

Update: Incidentally there is quite a bit of information on the PGI web site and a solid series of articles by Michael Wolfe published on HPCWire.

Does anyone think this is a surprisingly high figure? Even with TCO being a big talking point these days, many companies (especially in the Enterprise sector) appear slow to base their buying decisions on what can be loosely categorised as ‘Green Credentials’. Thinking about what better power efficiency means to most data centre managers, certainly at the higher end of the spectrum, it is that they get more absolute performance in a fixed space and power budget. At the lower end, initial capital expenditure is often the driving force, with TCO being a very distant consideration influencing the buying process.

Of course there are several reasons to call a system accelerated. The simple act of offloading one or more types of compute from the host CPU to a co-processor, can be viewed as accelerating the system, at least from the perspective of the user, because you have freed the host CPU from one burden and so it can perform other work. The co-processor, be it a fixed function unit, designed to offer certain types and levels of functionality, or a more general purpose device, capable of carrying out not just a single function, but several and potentially at greater levels of performance than before.

Contrary to what seems to be popular belief, heterogeneous systems are certainly not new, they have in the form I’ve just described, been around for a very long time indeed. Consider the personal computers of today. If you look inside you will likely find in addition to the x86 CPU, a DSP responsible for the multi-channel audio, a processor dedicated to the network interface, and last but very definitely not least, a graphics card that drives the lustrous visual experiences that are today’s user interfaces and games. In fact it will quite possibly be performing many other image processing related tasks, such as video transcoding. The humble PC has indeed come a long way from IBM’s original Personal Computer.

From the perspective of HPC users, which at Petapath we are typically concerned with, an accelerated system is one which takes advantage of the prodigious memory bandwidths and raw FLOPS available in today’s high end GPUs or custom designed accelerators and harnesses them to accelerate its particular processing intensive needs.