Introduction

NVIDIA GeForce GTX 670 launched today, and we have had the chance to review as many as four unique graphics cards based on it. It also gave us the opportunity to pair two of these cards in 2-way SLI configuration to test how performance scales up. Before you proceed any further, make sure you're up to speed with our single graphics card reviews:

• NVIDIA GeForce GTX 670 (reference design)
• ASUS GeForce GTX 670 Direct CU II TOP
• Palit GeForce GTX 670 JetStream Edition
• ZOTAC GeForce GTX 670 AMP! Edition

NVIDIA GeForce GTX 670 comes at a good point in time. It closely follows Intel's 3rd Generation Core processor family launch, which presents PC enthusiasts time to upgrade, particularly to PCI-Express 3.0 platforms. Our recent review covering PCI-Express scaling of GeForce GTX 680 and Radeon HD 7970 over the three generations of PCI-Express, and in various lane configurations, proved that PCI-Express 3.0 x8 provides bandwidth that yields performance identical to that of PCI-Express 2.0 x16, and that PCI-Express 3.0 x16 makes these current-generation high-end GPUs no more than 1% faster.

The PCI-Express scaling results give confidence to enthusiasts to opt for the Core "Ivy Bridge" platform, since on most multi-GPU capable 7-series motherboards, the lone PCI-Express 3.0 x16 link from the processor is split into two x8 links (or x8 + x4 + x4, on some motherboards). While NVIDIA's $399 GeForce GTX 670 has much to offer, we investigate the viability of following an incremental upgrade path, in which you buy one card now, and a second card when your games are beginning to get the better of the GPU, or when you've upgraded your monitor to a higher resolution. By today's prices, GTX 670 2-way SLI is a $798 solution. Two other competitors to look out for in this review are the recently-launched GeForce GTX 690 dual-GPU graphics card, which costs $999, but is selling for as high as $1,200; and GeForce GTX 680 2-way SLI, which provides the same performance for $998. In this review, we will test a 2-way SLI configuration of two GeForce GTX 670 2 GB graphics cards, running at NVIDIA reference clock speeds, through our entire performance test-bench.