AMD Radeon HD 7870 GHz Edition & Radeon HD 7850 Review: Rounding Out Southern Islands

Meet The Radeon HD 7870 & Radeon HD 7850

For today’s review AMD sent over a 7870 and a 7850. Both are built on the 7870 reference design, so the cards are functionally identical except for the configuration of their respective GPU and the number of PCIe power sockets present.

For retail cards this will be very similar to the 7700 series launch, with partners doing semi-custom cards right away. In fact among the list of cards AMD sent us only Club3D will be using the complete 7870 reference design, while everyone else will be using the reference PCB along with their customary open air coolers. The 7850 will be even more divergent since AMD actually has a different, shorter reference PCB for these cards. Consequently our 7850 has very little in common with retail 7850s when it comes to their construction.

The Radeon HD 7850 Reference Design - Only Sampled To Partners

Starting as always with the cooler, the 7870 reference design is effectively a smaller version of the 7970 reference design. Here AMD is once again using a blower design with a slightly smaller blower, shrouded in the same hard red & black plastic as with the 7900. Underneath the shroud we find AMD’s heatsink, which utilizes a copper baseplate attached to 3 copper heatpipes, which in turn run into an aluminum heatsink that runs roughly half the length of the card. This is fairly typical for a blower design for a sub-200W card, but again almost all of the retail cards will be using a completely different open air design.

The 7870 PCB itself runs 9.5” long, with an additional .25” of shroud overhang bringing the total to 9.75”. Our card is equipped with 8 5GHz 256MB Hynix GDDR5 memory chips, the same 5GHz chips that we saw on the 7700 series. For the 7870 power is provided by a pair of 6pin PCIe power socket, while the sub-150W 7850 uses a single socket. Both cards feature a single CrossFire connector, allowing them to be paired up in a 2-way CrossFire configuration.

Meanwhile for display connectivity AMD is using the same configuration as we’ve seen on the 7900 series: 1 DL-DVI port, 1 HDMI port, and 2 miniDP ports. Interestingly, unlike the 7900 series and 7700 series there is a set of pads for a second DVI port on the card, and while AMD doesn’t make use of them at least one XFX card will. The 7800 series as the same display configuration options as the 7900 series though, so while it can drive up to 6 monitors it can only drive 2 TMDS type displays at once, and if you want to drive a full 6 monitors you’ll need a MST hub.

Finally, I wanted to touch on marketing for a bit. We typically don’t go into any detail on marketing, but with the 7800 something AMD did caught my eye. One of AMD’s marketing angles will be to pitch the 7800 series as an upgrade for the 5800 series; AMD doesn’t typically pitch cards as upgrades in this manner, and the 5800 comparison is especially odd.

At 2.5 years old the 5800 series is no longer the video card king but it’s also not particularly outdated; other than tessellation performance it has held up well relative to newer cards. More specifically, the 7800 series performance is roughly equal to the 6900 series, and while the 6900 series as a step up from the 5800 series it was not a massive leap. With its $350/$250 MSRP the 7800 series has common pricing with the 5800 series, but at only 20-40% faster than the 5800 it’s not the kind of step up in performance that typically justifies such a large purchase. Of course AMD’s conservative pricing has a lot to do with this, but at the end of the day it’s odd to call the 7800 series the upgrade for the 5800 series when the 7950 is the more natural upgrade from a performance perspective.