ATI HD4870 & HD4850 Crossfire Performance Review

by Michael "SKYMTL" Hoenig     |     August 7, 2008

The Cards: What Worked & What Didnít

Without a doubt, Crossfire is quite a bit more versatile than Nvidiaís SLI since different combinations of cards can be used instead of always having to use cards of the same model. This means that instead of only having to use a pair of HD4850 cards; you can actually combine one HD4850 and one HD4870. While there have been a myriad of different cards in the past that support Crossfire, in this review we will only be discussing the current 4-series of cards. We will also touching very briefly on the possibility of using a 3-series card in combination with one of the current generation products on this page but as you will see, it stops there.

While other combinations are available by combining more than a pair of ATI cards together, we wonít be broaching that subject since at this time only a few AMD 790FX boards support this feature along with a rare X48 board here and there. We donít have one of these boards and neither do the vast majority of those of you who are considering Crossfire on your X38, P45 or X48 boards so we will keep this section firmly grounded in reality.

So, letís check out the possibilities and a little more about what they bring to the table.

The Crossfire Connector

Before we look at the cards, letís touch on what can only be called the heart of any modern Crossfire system: the Crossfire connector. It is basically a flexible interconnect which links one card to the next and unlike SLI, there needs to be two connectors attached to the cards at all times. Every Crossfire-enabled card now comes with a single bridge connector which means that once you have a pair of cards, all you will need is a Crossfire-enabled motherboard and you are off to the races.

HD4870 + HD4870

In these last few days before the release of the R700, the combination of a pair of HD4870 cards is the most power Crossfire solution most of you will have access to. Considering the price of a HD4870 is now in the realm of $270 and a pair of them will run you a shade over $540, there was a short time when you could get a pair of these cards for less than a single Nvidia GTX 280. However, as the prices of the Nvidia cards have come down and this solution has become slightly less appealing but nonetheless should provide the best possible performance on a motherboard with an Intel chipset. In this case we are using a pair of stock Palit cards.

HD4850 + HD4850

In what can only be called ďCrossfire on a budgetĒ, ATIís new HD4850 cards can be combined for some supposedly impressive performance increases over a single card. Considering this solution will currently put you back less than $400, it comes in at less than the price of a stock-clocked GTX 280 card sells for. It seems like this is by far the most popular Crossfire setup right now with many owners of the new P45 boards first buying a single HD4850 and then when seeing another one on sale, grab up a second one for increased performance. For our tests, a pair of Sapphire stock-clocked cards was used.

HD4870 + HD4850 (mixed Crossfire)

Now we come to something a little bit more interesting: mixed Crossfire. With this you are able to combine two different cards of the same series while still getting increased performance over a single card. This provides quite a bit of versatility to people who may happen to inherit another card from their brother or friend. However, is it worth it to actually buy one of each card? We will find out in our testing.

HD48xx + HD38xx

Since we know you are going to ask, this option does NOT work. We tried with 5 different beta and WHQL drivers from the 8.6 to the newest 8.7 and not one of them allowed us to enable Crossfire between two different families of ATI cards. Before anyone asks in the comment thread, we have confirmed the incompatibility with ATIís driver and product teams.

Latest Reviews in Video Cards
November 1, 2017
Enough of the endless unboxings, rumors and presumptions! The GTX 1070 Ti is finally here and it's performance results are impressive to say the least!...
August 14, 2017
After nearly two years of teases, AMD's Vega 64 and Vega 56 have finally arrived. Can these two graphics cards really compete with NVIDIA's Pascal lineup?...
July 30, 2017
AMD has finally revealed almost everything there is to know about RX Vega including its pricing, performance and specifications. Is it a disappointment or everything we were hoping for?...