AMD explains 4X4 to the world

The main thing it talked about was the term 'megatasking' basically a lot of tasks, or a few really heavy tasks. To do any of this, AMD thinks you need not only four cores, but four cores and more memory bandwidth. In this, it is correct.

Power users I know all have at least two systems beside the comfy chair with their butt's impression permanently moulded into the foam - one for work, the other for gaming. The 4X4 concept seems to be all about combining those two systems into one, one that you can do all the things you want, and not see any slowdown.

The hardware itself consists of two dual core CPUs and four GPUs, hence the 4X4 moniker. AMD said there is not going to be just one 4X4, there will be a range of 4X4s, including at least two with a price under $1,000. It will also be branded FX in one way or another.

This is in stark contrast to the current FX line, or at least the current FX chip. These are only sold in the highest speed bin, and there is only one at a time. With the 4X4 line, it will be physically different, so there will be no pesky "an FX-57 is different from a straight A64, how?" questions, it is different.

Basically, the chips will be standard A64 X2s with at least 1 ccHT link not turned off so they can talk. If there is any special sauce, AMD did not talk about it , and I would not expect any earth-shattering jumps in performance on single- or low-threaded games. AMD also said the concept will carry over to eight cores, two quad-core chips, but they won't be called 8X4.

That brings us to the point of the 4X4 - you can encode a DVD while playing UT2007, it won't bring the system to its knees making both unusable. AMD demonstrated that many times, with various things running in parallel, and not trivial ones at that. AMD also talked about 4X4 running a game server beside the game itself without causing chugging, take that you LPBs, an HT link has pretty low ping times. Below, you can see the 3DMark06 CPU tests, it had an FX-62 running on the left, a 4x4 of indeterminate specs on the right. The left started first, the right ended first.

If games are amenable to massive threading, they will do really well on the 4X4 platform, exceptionally well in fact. If they are not all that threaded, the whole "megatasking" idea comes into play. One of the things at Tim Sweeney said at E3 was the current way of doing 3D had two heavyweight threads that are fundamental to the way games are written and processed. These threads are not easily broken down, and currently, you really can't. The rest of the game - things like sound, UIs and IO take less than a modern core's worth of CPU time, but they are quite amenable to threading.

That leaves you with 2.5 cores worth of tasks, and you have four. If you spread those .5 CPU tasks out as much as possible, you are still at 2 x .25, or two CPUs more or less loafing along. On a normal PC, if you decided to rip the new pre-packaged, focus-grouped corporately palatable mushy-music CD at the same time, you would end up with serious memory contention.

Again, with 4X4, you end up with double the memory bandwidth, so this is far less of a problem. With clever software you can partition it so the game gets all the CPU it needs, and no less than a normal CPU's worth of bandwidth. Could this be the 'special sauce' I keep hearing about?

Either way, don't expect the gaming crown to be magically torn from Intel when 4X4 comes out, that will only happen on a very specific subset of games. The rest will have a much more responsive and usable system than a single CPU, and if AMD can hold the line on price, that seems like a pretty good deal. µ