Club Overclocker - Sapphire Radeon HD4870X2 2GB Review!

Boy, what a ride the last few months have been. While the star of ATi had fallen considerably with the launch of the R600-based HD 2900 XT, they have more than made up for it with the launch of the RV770-based 4850 and 4870. While nVidia was basking in the glory of the GTX-260 and GTX-280, ATi came out of nowhere and completely took the wind out of their sails with the price-performance friendly 4000 series. In turn, nVidia responded by slashing prices and launching the 9800GTX+.

Of course, ATi has a counter-punch ready, and it is being unleashed on nVidia's chin today. It is the R700 based 4870X2, and we are going to see if lands squarely, or if it is a whiff. Before we start in on the benchmarks, let us look at what is behind the R700 and what it can bring to the table.

	4870X2	4870	4850
Stream Processors	800 x 2	800	800
Texture Units	40 x 2	40	40
ROPs	16 x 2	16	16
Core Clock	750MHz	750MHz	625MHz
Memory Clock	900MHz GDDR5	900MHz GDDR5	993MHz GDDR3
Memory Bus Width	256-bit x 2	256-bit	256-bit
Frame Buffer	1GB x 2	512MB	512MB
Transistor Count	956M x 2	956M	956M
Manufacturing Process	TSMC 55nm	TSMC 55nm	TSMC 55nm
Price Point	$549	$299	$199

As we can see from the above table, the 4870X2 is exactly what it says it is; two 4870s crammed onto a single card, with one exception. While the standard 4870 is equipped with 512MB of RAM, the 4870 has 2GB of GDDR5, all running at 900MHz, or 1800MHz effective. This is fairly impressive, as most dual-GPU cards end up toning down the clock speed in order to keep heat in check.

A couple other items here are also worth taking note; there have been lots of rumors about the R700 being the first card to utilize a unified frame buffer, considered by many to be the holy grail of multi-GPU gaming by making the memory core agnostic, and thus much more efficient. It turns out that this is not the case for the R700, we are still going to have to wait for that, however, AMD has hinted that there is some GPU to GPU communication going on in the R700 that promises to make it more efficient than the typical two card Crossfire setup.

Before we continue on, I must admit that I have never been a fan of multi-GPU setups. Too often, there has been issues with price to performance ratios, driver problems, and compatibility, not to mention heat and power consumption. In a sense, multi-GPU has always seemed "half-assed". With that being said, we will be taking a very close look at the 4870X2 with a critical eye, and we will see if AMD can sway me over to the multi-GPU camp.