AMD's R600 mysteries revealed

[Alpine]

Welcome Overdrive, vapour chamber cooler and 12 inchers

ATI'S coming R600 launch is causing fevered speculation and engendering widespread confusion.


Pictures of R600XTX OEM/SI version made the web rounds last weekend, and many readers got asked us what's going on with AMD.

Firstly, the PCB design of these products pictured are identical to the final form factor, and around nine inches long. And there will be a special cooler, designed as a one-off.

We can now reveal to you that the board you have been seeing around the web is actually a specific design which has only one customer right now. The name of that customer is Apple and it will also be available in Crossfire mode.

While we have zero doubts that Dell XPS/Dellienware and some other parties will pick it up as well, right now, the nice red cooler design is just Apple's and Apple's alone.

Personally, I have no doubt that Voodoo PC will ship the R600 with its water-cooling block. The company decided to go with vapour chamber technology, or a 2D version of the traditional heatpipe concept we have all come to know and endure.

Vapour Chamber technology is pretty well known in the world of CPU cooling, thanks to the Danish company named Asetek, and its "VapoChill" systems which propelled CPUs beyond the limits of water-cooling.

Asetek also made a conventional VapoChill Micro cooler, and you can perhaps visualise the R600's cooler as the VapoChill Micro for the GPU. We don't know yet which firm will produce this cooler for AMD/ATI, but we suspect only one or two players are in the frame. Now, the power connector story is a pretty interesting one. At present, there is actually only one design for both OEM/SI and retail/AIBs, and that one is 8-pin/6-pin. You can use 6+6-pin configuration, but if you do not plug 8-pin/6-pin, the ATI Catalyst driver suite will forbid you to enter the "Overdrive Zone".

Yes, you've read it right - the R600XTX is coming out with a legal overclocking mode, no nonsense and limiting overclocking to its partners like some other companies have. The clocks have not been set yet. Even AMD is waiting until a couple of days before the launch before it makes that decision.

The current estimate is that the memory will float between 1 and 1.1GHz GDDR-4 memory in DDR mode (2.0-2.2 GHz), while the GPU clock will be set around 800MHz. Some say 826MHz, but we're not sure how far the Overdrive will go. We'd say not beyond 850 MHz, but that is just my personal opinion.

Our sources tell us that the clock bump should be around 10 per cent for the GPU and 14 per cent for the memory, bringing the total clock to 880/2400-2600. It is insane to see a 700M+ 80nm transistor chip run at such a high clock, especially given the limitations the G80 had with sub-700M chip and 90nm process, but this is an industry where anything that can happen will happen.

These estimates are for the A13 revision. As we wrote quite some time ago, AMD/ATI decided to re-spin the chip to solve some problems it had with the product. It turns out that those problems involved engineers trying to get as high a clock as possible and to try to lower the power consumption, which is pretty steep right now - but still within do-able limits.

The BIOS for the board is now a "smart" one - it will detect whether the GPU is leaking current and will throttle power to prevent thermal or electrical "episodes". So, the R600XTX has a special OEM/SI design mostly for Apple, the retail versions won't come with water cooling, but rather advanced vapour chamber technology, and the board has 8/6-pin config but can be used with two 6-pin ones - in which case you'll lose the Overdrive feature and stay inside a 225W power envelope, just like Nvidia Geforce 8800GTS . We will bring you more details about the connectivity of R600 boards later in the day.

The INQuirer