A Closer Look at the ATI HD3870 X2


The first thing that becomes apparent when looking at the HD3870 X2 is that it is one heck of a long card with a massive cooler. Fitting two GPU cores and 1GB of memory takes up a fair amount of real estate, so the overall length of this card had to increase quite a bit over that of the HD3870.

As with all of ATI’s cards for as long and anyone can remember, it is decked out with a bright red PCB and red plastic heatsink. Unlike cards like the HD2900XT with its silver flame design or the HD3870 which didn’t have much design at all on the stock heatsink, this sample came with a decal of Ruby’s (ATI’s femme fatale mascot) eyes.


As you can see, even though the HD3870 X2 is quite long, it equals the length of the 8800GTX which is 10.5”. This is actually quite a feat on ATI’s part since the 8800GTX has one GPU while ATI’s new flagship holds two GPU cores. On the other hand, this card is much longer than the standard HD3870.

The best way to tell if this will fit into your case is to do a bit of quick measuring. If you have a standard ATX-sized motherboard, measure a straight line from your motherboard's x16 PCI-E slot to the edge of your motherboard. If from that edge you have 1” or more before hitting into any barrier, you will have enough space for this card.


The fan ATI used for the heatsink on the HD3870 X2 looks a lot like the horribly loud affair which was used on the HD2900XT. We will see what happens in the Heat and Acoustics area, but since the two 55nm RV670XT cores don’t produce much heat, I am hoping the RPMs of this fan are kept to a minimum.

There are two sections of copper fins (on this particular card one of them is aluminum) without any accompanying heatpipes inside the heatsink itself. Each of these sections lines up with one of the two GPU cores. Cool air is brought in by the fan, passed over the copper fins and then exhausted through the back of the card so it does not seep into your case.


Other portions of the card including the ram modules are passively cooled my aluminum “pegs” which disperse any heat buildup. Here you can also see a bit more of the inner workings of the heatsink itself with the two blocked in fin areas above the cores.


Let me say this right away: I am not a fan of the power connector placement on the HD3870 X2. While single 6-pin and single 8-pin connectors are sure to bring enough power to the two cores and their accompanying bridge chip, I have an issue with the angle they are placed at. Most cards (including the now-defunct HD2900XT) have their power connectors placed so they are in-line with the PCB. Unfortunately, the connectors on this card are placed at a right angle to the PCB which means the PCI-E cables will have to do a bit of acrobatics to reach the card. This is especially true if you have a top-mounted power supply.

The Crossfire connector is different from other recent ATI cards since it has only a single connector. Other ATI cards of late have had dual connectors which means you can daisy-chain up to 4 cards together if you have a supporting motherboard. With the HD3870 X2, you can only link two cards together which would still equal 4 GPUs all running together. One way or another, running two of these cards together is every enthusiast’s wet dream.


The backplate of the HD3870 X2 has the usual DVI connectors as well as an HDTV-out connector. Like with all of ATI’s recent cards, this one also offers a DVI to HDMI adaptor for all your high-def audio and video needs.


The underside of this card is markedly different from anything else we have seen here at Hardware Canucks. There are two distinct areas with the GPUs as well as a large black aluminum plate which is used to disperse heat from the ram modules and add a bit more structural stability to the PCB. The last time I saw this was with the HD2900XT and this plate got hotter than hell itself when the card was in use.