Asus EAH3850 X3 Trinity, world’s first benchmarks of triple-GPU card

Posted at: Tuesday 8th April 2008 by Ben Hardwidge

It’s a world-first graphics card, with 1.5GB of RAM and three Radeon HD 3850 GPUs, but does Asus’ engineering side-project actually work? We put the EAH3850 Trinity through its paces to see what three GPUs get you in today’s games

Any decent cliché dictionary will tell you that two’s company but three’s a crowd, and graphics cards don’t come much more crowded than the EAH3850 X3 Trinity showcase card from Asus. It’s saddled up with three mini Radeon HD 3850 cards, attached to the main card via mobile MXM connectors. There’s a reason why this card has an air of the Heath Robinson about it, though - it was the result of a fun side-project by Asus’ engineers and R&D guys, and is not intended to ever make it to the shops.

Even so, some of Asus’ previous eccentric tech projects such as the EN7800GT Dual made it to the production line in the face of strong demand, so we wanted to see how this monster fared in our graphics benchmarks. Besides, while we’ve tested plenty of dual-GPU cards, we’ve never got our hands on a triple-GPU beastie before. We felt pretty chuffed when Asus kindly agreed to let us take one of the ten existing Trinity cards into our labs.

The Trinity

Before we get onto the benchmarks, let’s have a look at the composition of this bizarre contraption, as getting three GPUs onto a single 290mm long card has required some pretty nifty engineering from Asus. Firstly, ATI doesn’t officially make Mobility Radeon HD 3850 cards for laptops so Asus has had to design and construct a mobile Radeon HD 3850 itself. And then Asus needed to design and make the main card that these three mobile cards connect to.

The three GPUs are clocked at 660MHz, and each have 512MB of 850MHz (1.7GHz effective) memory with a 256-bit memory interface. These are near-enough the usual clock speeds of a desktop ATI Radeon HD 3850, only shy by a few MHz here and there.


The GPUs still each have the usual 320 stream processors of a desktop Radeon HD 3850 too, and so (barring any bandwidth issues with the MXM connectors or elsewhere) the Trinity should perform like three Radeon HD 3850 cards teamed in CrossFireX mode. Asus told us that it couldn’t use Radeon HD 3870 GPUS, as that would lead to bandwidth issues. Impressively though, the Trinity only requires a single 8-pin PCI-E power connector while three separate Radeon HD 3850 cards would require three 6-pin connectors.

One MXM card is mounted on the front of the main PCB, with the other two on the back, making for a massive card with a total of 1.5GB of memory. Each GPU is connected to its own pair of copper heatpipes, which lead to a block on the end of the card that hooks up to a Thermaltake BigWater 760i water-cooling system. Even without the double-drive bay radiator/pump/reservoir of the BigWater 760i, the Trinity is one of the biggest graphics cards we’ve ever seen.