AMD Radeon HD 4770 CrossFire Review

For near the same price as a single Radeon HD 4890 1GB video card you can install two Radeon HD 4770 video cards in a dual-GPU CrossFire configuration. The question is, “What kind of value and performance do both configurations provide and which one is going to give you the best gaming experience?”

Introduction

When the AMD Radeon HD 4770 launched on April 28th, 2009, we evaluated a single video card and found stellar performance for the price. This small piece of hardware, innocent at first sight, was able to pack a punch where it counts in gaming performance at an unheard of price for the performance delivered.

With the introduction of this video card, at or near the $100 mark, some interesting configuration options are now available. Doubling two Radeon HD 4770’s up for $200 allows you to benefit from multi-GPU performance with Radeon HD 4770 CrossFire. While that is great in itself, there is already a single-GPU video card sitting at the $200 mark to compete with that configuration.

Radeon HD 4890 vs. Radeon HD 4770 CrossFire

The Radeon HD 4890 1GB was launched a month prior to the Radeon HD 4770, back on April 1st, 2009. The Radeon HD 4890 has been enjoying a steady decline in pricing as the months have gone by. You can now get Radeon HD 4890’s (with rebates) under $200.

This current pricing creates fierce competition between the Radeon HD 4770 CrossFire configuration and an HD 4890. It is fierce because when you look at both GPUs from a technical standpoint two HD 4770’s with CrossFire enabled basically “doubles” their shader specifications. For example, the HD 4770 contains 640 stream processors, while the HD 4890 contains 800. However, with two HD 4770’s and CrossFire enabled you have basically doubled the available shader count to 1,280 stream processors, surpassing a single HD 4890. As CrossFire isn’t 100% efficient though, you will not get the full benefit of that, but we are here to find out just how well it actually does in comparison.

One area of the video cards that does not get “doubled” with CrossFire is the memory subsystem of the video card. The Radeon HD 4770 video cards are limited by being able to access only 512MB of RAM per GPU while the HD 4890 has access to a full 1GB. Also, the memory bus is wider on the HD 4890 with faster frequencies. With CrossFire each GPU has access to its own 128-bit memory bus with 3.2GHz GDDR5 while the HD 4890 can access its memory through a 256-bit bus with memory running at 3.9GHz GDDR5.

That means it sounds like, at least on paper, there are some shader performance benefits with Radeon HD 4770 CrossFire over a single HD 4890, but it may struggle in highly memory intensive situations. We will certainly find out. We will also be including a single Radeon HD 4770 in our testing to see the advantages adding another 4770 will provide over a single HD 4770 as well.

Configuring CrossFire these days couldn’t be easier. We simply installed both Radeon HD 4770’s into our computer, connected both CrossFire bridge connectors, and booted right up. In Windows 7 we installed the latest driver, the computer rebooted and CrossFire was enabled by default. We had no issues getting CrossFire to work; it worked “out-of-the-box” for us.