Upcoming Graphics Card Changes

Not the most specific title, I know. It is however, a title that gives what the post is about – general changes in graphics that are on the way to the consumer market.

I just got through reading a very good article on Tech Radar, that first, gives a brief history of how graphics processors have evolved. This is a good start, as many really don’t know. This includes many who are avid game players, who have no clue how it all started.

Today’s graphics cards do things today that were once handled by the CPU, on machines that were dedicated to graphics alone, with hefty price tags, and monitors that would only connect to those machines through proprietary connectors.

The article spells out a few things, and points to other things that many don’t quite realize – such as 12 reasons PC gaming is better than consoles.

After reading the article, and getting a little history, the author gives his ideas about the Intel Larrabee, and how it will change things.

As testament to the idea that shaders are becoming processors in their own right, Intel is wading into the graphics arena and the ripples could permanently erode the market that once seemed so rock solid.

As we already know the new GPU is codenamed Larrabee and its heart is based, in part, on the original x86 Pentium core. Intel is on record as saying it can, in theory, run OS kernel level code. The idea is to take a bunch of optimised, in-order x86 Pentium cores, add in a Vector Processing Unit and tie the whole thing together via each core’s L2 cache using a high-speed ring bus.

Alongside the multi-core design there’s a dedicated texture filtering unit, plus the usual extra gubbins for the memory controller, display and system interfaces. Intel is approaching the problem in the opposite direction to AMD and Nvidia. It’s almost dumbing-down an x86 core to help fit as many as possible onto a GPU die.

All parties are selling these as more than just a graphics solution. Intel is partnering with Dreamworks, who will be using Larrabee as an accelerated computing platform for ray tracing frames within its animated features. With Intel measuring a 1GHz, 24-core Larrabee GPU running almost five times faster than an eight-core Xeon processor at 2.6GHz at ray tracing. This shows the huge acceleration potential GP-GPU solutions have in the real world.

Currently no one has any idea how well Larrabee will perform, if it performs at all. However, we managed to dig out some figures from a paper Intel published. It estimates the performance of a Larrabee processor running F.E.A.R., Gears of War and Half-Life 2: Episode 2. The most interesting section took the DirectX commands generated from a sequence of random frames from each of these games.

These commands were fed through a ‘functional model’ of Larrabee rendering at 1,600×1,200 with 4x AA. The test was to see how many 1GHz cores were required to keep a constant 60fps output for each game. The answers is between 10 and 24 cores depending on the game.

Clearly this is nowhere near the performance of top-end cards, the frames would have to be nearer 180fps at that resolution, but even so at 3GHz with 24 cores that would be achievable and still in the realms of reality.

This multicore general purpose GPU (MC GP-GPU) is going to change things, but I can’t help wonder if much ado is being made over something that will be not nothing, but significantly less than what we might think, if only because it’s been so long in coming.

By the time Larrabee launches, it could be almost 2010 and both Nvidia and AMD will have had next-gen DirectX 11 devices well out of the stable. Intel’s own figures show that its core scaling works well up to and over 48 cores with apparently only a two to ten per cent drop in performance.

It’s impossible at this stage to know how much a Larrabee card will cost, but we can make several massive assumptions based on existing technology.

For example, a 24-core GPU would require 6MB of L2 cache, that’s roughly 300 million transistors. Lets guesstimate that the x86 modified Pentium cores are twice their original sizes at 6 million transistors, that’s around 450 million transistors in total for a 24-core Larrabee GPU.

Now, if you accept those transistor counts and accept fab costs are closer to that of a full processor than a GPU, at roughly half the transistor count of a 3GHz Core i7, the consumer price could be up to £230. That’s not including the 1GB of GDDR5, of course.

The issue is whether Intel can put out a GPU that’s affordable and a good performer, when the Larrabee’s launched. At least AMD and Nvidia will put us out of our misery soon enough, as they’re both expected to field hardware supporting DirectX 11 in the second half of 2009.

Certainly Larrabee will be a big deal, simply because it comes from Intel, but given the expertise that is available in the AMD/ATi and nVidia camps, I’m sure it won’t be a slam dunk for Intel.

The article talks about DirectX 11, yet most people are still waiting to see the non-videogame benefits of DirectX 10.

With the eventual adoption of Windows 7 (people will, simply because they like something new, and it’s been so long since Microsoft supplied new, and good, in the same package) and the touch capabilities, graphics drivers, and chips will have to cope with so much more, and the improvements we’re seeing today will be put to good use for the everyday user.

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