Introduction

A part of what makes the Radeon R9 290X an exciting option at its price is that two of them only cost 10% more than a single GeForce GTX TITAN. If you don't already know what kind of performance is on offer at $549, check out our comprehensive review of the Radeon R9 290X AMD is already talking a lot about how the R9 290X is ready to deal with the new generation of 4K Ultra HD monitors, which beam out 3840x2160 pixels (about 8.2 million pixels). We've been testing 5760x1080 (about 6.2 million pixels) for a while now and are fairly confident that the current generation of high-end graphics cards shouldn't make games seem like slide-shows at Ultra HD. Two of them in multi-GPU configurations stand an even better chance.In this review, we put CrossFireX configurations with two Radeon R9 290X graphics cards to the test. Since the R9 290X comes with two BIOS modes, "Uber" (high-performance) and "Quiet," we treated CrossFireX configurations with cards running the two as distinct data points. You'll find the "R9 290X CrossFire Uber", with both cards running the "Uber" BIOS, and "R9 290X CrossFire Quiet", with both cards running the "Quiet" BIOS, pitted against a single R9 290X and other high-end graphics solutions. A hybrid configuration of "Uber" and "Quiet" R9 290X is possible, although we found it to perform too inconsistently to include in the review.The Radeon R9 290X is the first high-end graphics card from AMD since the introduction of CrossFire that lacks a physical interconnect between cards participating in a multi-GPU setup. Even the very first Radeon X1900 XT cards relied on a cable to pass CrossFire data between cards. The R9 290X relies on the PCI-Express bus to relay CrossFire data between other cards in the CrossFire setup—no CrossFire fingers or CFBI ribbon cables run between the cards themselves. AMD assured us that such a setup doesn't affect performance or frame-latency, stating that it is in fact better suited to high-resolution display heads, such as 4K Ultra HD. We began the test by slipping into more summery clothes.