AMD Radeon HD 7870 GHz Edition & 7850 Video Card ReviewSun, Mar 04, 2012 - 11:05 PM
Radeon HD 7870 GHz Edition Up Close
As we mentioned on the previous page, AMD sent over both the Radeon HD 7870 GHz Edition and Radeon HD 7850 reference design cards. Both cards are virtually identical with the exception of the Radeon HD 7850 as it has just a single 6-pin power connector on the top. The AMD informed us that the Radeon HD 7850 that they sent us would never be sold as board makers would be using shorter 8.25-inch PCBs and custom GPU coolers. Since the Radeon HD 7850 we have will never see the light of day we won’t be showing you a million pictures of it.
The Radeon HD 7800 series has the usual red/black color scheme with high-gloss black plastic fan shrouds. This finish makes it hard to take pictures of them and it also makes finger prints clearly visible, so after installing a card in your system you’ll need to wipe it down.
As you can see from the photo above, both cards use a dual-slot cooler with a single cooling fan located at the end of the card.
The AMD Radeon HD 7870 GHz edition video card has a black PCB and measures 9.5-inches in length. It should be noted that the fan shroud barely protrudes past the PCB making
the overall length of the Radeon HD 7870 GHZ Edition to be ~9.7-inches. The height of the card is just shy of 4-inches if you count what sticks out of the PCI Express x16 slot.
The back of the Radeon HD 7870 is open as the reference card doesn’t feature a back plate. Not too much to talk about back here as none of the 2GB worth of GDDR5 memory chips are visible on this side of the PCB. The only thing worth noting here is the GPU support bracket and mounting holes appear unchanged from previous generations. We measured and found that both cards are using 53mm mounting holes, so you you plan on changing the GPU cooler or adding a water block you’ll need to know this dimension. The AMD Radeon HD 7870 GHz Edition reference PCB model number is 109-C40147-00.
The AMD Radeon 7870 GHz Edition and the Radeon HD 7850 have just one CrossFireX interconnect,
so you can only run CrossFire with another card (two cards total). Notice that just above
the CrossFire interconnects are some black bumps
with some spaced between them. This is actually an air vent for the
GPU cooler and a decent amount of airflow does come out here despite
being such a small opening. The AMD Radeon HD 7870 and 7850 do not have
the ‘Dual BIOS Toggle Switch’ that is found on the Radeon HD 7900 series cards.
The AMD Radeon HD 7870 GHz Edition has a pair of 6-pin PCI Express power connector
located at the end of the video card. The AMD Radeon HD 7850 requires just one 6-pin connector.
The AMD Radeon HD 7870/7850 have a pair of mini-DisplayPort 1.2 connectors
on it that have double the data-rate of DisplayPort 1.1. In addition
to the higher data-rate, DP 1.2 also brings support for higher
resolution support and support for stereoscopic 3D. The Radeon HD 7800 series
supports AMD Eyefinity and up to six DisplayPort displays by “daisy chaining” them to the
two Displayport outputs. To the right of the pair of mini-DisplayPort
connectors is a full size HDMI 1.4a output for 3D video (Blu-ray 3D)
support and a dual-link DVI-I output. With full support for 3GHz HDMI
1.4a and DisplayPort 1.2 HBR2, the AMD Radeon HD 7800 series is set to drive
next generation displays at up to 4K resolution.
Notice that AMD did away with having two DVI outputs and by doing so
they opened up an entire side of the PCI bracket for exhausting the hot
air from the GPU. AMD said that by opening this side of the bracket up
and removing the DVI port there that they got two benefits. The first
is that the card’s thermal performance improved and the second was that the noise decreased as there is air flow isn’t blocked as badly.