Sapphire Radeon HD4870 X2 Review - PAGE 2

Impressions

Before we actually see how the HD 4870 X2 stacks up against other cards, let's find out what makes this beauty tick. The HD 4870 X2 has the same thing all 48XX chips have under the heat spreader. What's a little bit different is that it has two of these things. So what exactly are these things that the HD 4870 X2 has two of? You guessed it, the HD 4870 X2 has not one but two RV770 chips. The name should have given that one away though.

In terms of connectors, Sapphire's HD 4870 X2 follows a very common path. Rather then putting every possible type of video output you could imagine on the video card, Sapphire took the usual steps of using only two DVI ports. Along with these you'll also get the usual Component video output that is located in the center of the two DVI ports. If you're using a monitor that doesn't support DVI, then you're not completely screwed. Included with the HD 4870 X2 are connectors for just about any output that you'd need.

In terms of interfaces, the HD 4870 X2 uses the now familiar PCIe x 16 2.0. The 4870 X2 has a slightly different way of utilizing Crossfire. Instead of the usual two Crossfire connectors at the top of the card, you'll notice that there is only one. This is OK because the HD 4870 X2 is technically two HD 4870's Crossfired together, and if you think about it when you run Tri SLI each card is only connected by one Crossfire bridge anyway.

Looking at the back of Sapphire's HD 4870 X2 you can see that it actually has a backplate. What this will do is act as a heat spreader, which should hopefully cool the card a few extra C. You'll also notice that there are two brackets on the back of the card. What this tells us is that there is most likely two seperate heat sinks for the RV770 chips. At the top left under the SLI connector is the infamous dip PAL/NTSC switch.

Removing the HD 4870 X2's cooling solution was a little bit harder then I had expected. The first step was to remove the fan shroud, which was attached via screws on the backplate and screws on the front of the card. There were also a few screws near the DVI ports. This doesn't seem like much, but actually finding all of them was a pain in the butt. Alright I am exaggerating a little, but it did take longer then usual to remove the cooler.

Removing the cooler reveals nothing more than that there is more to the cooler that needs to be taken apart. There are 13 smaller screws located around the cooler, and one of them is located under a heat pad. Removing these screws could lead us to unimaginable treasures, or at least to a good look at the copper sinks and a fan. Then again to some people two copper heat sinks and a fan could be treasures. You never really know until you ask someone.

Both the cooler and the back plate are covered in heat pads. This tells us that there are components on both the front and the back of the PCB that will get hot. Hopefully this massive cooler will do a good enough job at dissipating the heat. You'll also notice that the heat pads appear to be oily, and that is because they are. For those of you that don't know, a heat pad feels like a mixture between chewed gum and a thin piece of clay. They're also relatively sticky and hard to put back in place, so I'd advise you to not touch them!

Popping open the cooler shows us the treasure that was hidden within. Inside the HD 4870 X2 cooler are two identical copper heat sinks. The sinks are chunks of copper with fins at the top. The fins are bent and should allow air to pass easily through them and out of the coolers back. I was a little disappointed by the heat sinks, especially after seeing some of the heat sinks on other cards. But, hey if it gets the job done, then might as well use it. The fan responsible for blowing the air through these cards is a stock fan mounted on a triangle. The triangle then attaches to the coolers shroud via three screws.

The fan shroud itself is nothing more than plastic. It locks the heat sinks and fan against the metal plate that comes into contact with the PCB. It will keep the air flowing directly through the heat sinks. It would have been nice if there were two fans, because one fan will be getting the hot air exhausted from the first sink. From the looks of it the cooler should be able to dissipate a fair amount of heat, but we'll just have to wait and see how it performs.

It's now time to look at the card itself. Just from looking at the PCB you can see that Sapphire's HD 4870 X2 is a bit different from your everyday video card. One of the first things I noticed was that there are four fairly large inductors. There are two "PULSE" models, and two from "VITECH." The "VITECH" inductors are designed for "advanced" voltage regulation. Not only that, but there are two of them. It kind of makes you wonder how much energy the HD 4870 X2 is going to consume. Another thing you'll notice is that there are only 4 memory modules around both of the RV770 chips. Normally there are 8 modules around 1 chip, so where are the other 8 modules? We'll find out in a bit.

Wait a minute!!! What's that thing in between the two RV770 cores? It's almost as big as the RV770 chip. It has it's own heat spreader, and it doesn't say ATI. This is a very low latency  PCIe switch made by PLX technology. It is used for the two RV770 cores to communicate between themselves. It can be thought of as a type of CrossFire bridge. More information on PCIe switches can be found on the companies website.

Taking a look at the back of the card we can see where the remaining eight memory modules ended up. Altogether the 16 modules add up to 2GB's of blazing fast GDDR5 memory, but there's a catch! Because, there is technically two cards in one the 2GB's of memory will be split between them. In the end it will be like 1GB of memory to the OS.

Specifications

The specifications for Sapphires HD 4870 X2 are a little bit tricky. Well not really, the HD 4870 X2 is technically two HD 4870's so just double the specs on one of those. To be more exact you'll get two RV770 cores running at 780MHz. You'll get 2GB of super crazy fast GDDR5 memory clocked at an even 1GHz. The 4870 X2 has two RV770 cores so that means it has 1912 transistors, 1600 stream processors, and a RAMDAC of 400MHz. If that's not enough for you, know that the 4870 X2 will give you a massive 2.4 Tera Flops of graphically insane power. If that doesn't do it for you, I'm not sure what will.

Two in One: HD 4870 X2, Toxic HD 4870, EAH4870

As with every 48XX series card, purchasing a 4870 X2 will get you a powerful GPU with both DirectX 10.1 and OpenGL 2.1 capabilities. You'll also be purchasing a card that is supposedly superior at HD decoding and playback.  The 4870 X2 utilizes UVD 2.0 Dual Stream Decoding, so that when you're decoding say a Blu-Ray disk your CPU doesn't take the LOAD. This could be very usefully if you're trying to do multiple things at once. It's almost like you're multi-tasking without using the CPU, kinda cool actually.