PowerColor package the Myst card in a familiar looking box. It notes the presence of boost technology and Windows 8 compatibility along with PCS+ cooling. Inside we find a basic bundle including a mini-DisplayPort to DisplayPort adapter and some retailers may bundle the Never Settle game pack which includes Far Cry 3 and money off Medal of Honor: Warfighter.
PowerColor use a black PCB for their Myst card and go with a dual slot cooler black shroud and single, central fan. Beneath it is a GPU block and aluminium fins and three copper heatpipes run across the GPU. Turning round to the back we can see the single CrossFire connector and note that this card connects to 7900 series models for Multi-GPU. Standard 7870 parts are not supported in CrossFire.
The 7870 Myst is powered by dual 6-pin connectors and round at the card outputs we find DVI, HDMI and dual mini-DisplayPort. This of course means Eyefinity configurations such as 3 screens running 5760x1080 are possible.
Earlier we noted that this card uses the Tahiti GPU, rather than Pitcairn which is normally found on 7800 series cards. What does this mean? Well in simple terms it is all about how much of the GPU is enabled. On the likes of the 7970 a Radeon GPU has 2048 "cores" or "stream processors", 32 ROPs and a 384bit memory bus. The 7870 on the other hand has 1280 stream processors, 32 ROPs and connects to the cards memory via a 256-bit bus.
With the 7870 Myst PCS+ PowerColor land somewhere in-between using a 256-bit memory bus with 1536 stream processors. Sticking with the 7900 style design though they also include boost technology which has the cards GPU, through PowerTune, able to manage power and speed on the fly, increasing the MHz as required/allowed up to a maximum of 975MHz (925MHz Standard). PowerColor also look more towards the Tahiti spec when it comes to memory too with the 2GB of GDDR5 clocked at 1500MHz.
Finally, as with all recent Radeons PCIe 3.0, DirectX 11.1 and DirectCompute are all supported on this card as is acceleration of high definition content and the card can output 7.1 audio over HDMI, ideal for HTPCs.