PowerColor Radeon HD 7790 Turbo Duo Reviewccokeman -
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PowerColor Radeon HD 7790 Turbo Duo Closer Look:
PowerColor's HD 7790 Turbo Duo is most definitely a reference card masquerading as an aftermarket design. From the front this is clearly evident with the use of the aggressively styled Turbo Duo fan enclosure that uses a pair of fans coupled with an S-shaped heat pipe-equipped heat sink. From the back you can see the openings in the PCB, called an "Aerodynamics Kit", that provides another avenue for the thermal load to exit from under the shroud. The top and bottom views give little clue as to the shape of the enclosed cooling solution. Designed around the latest AMD 28nm GCN core, the HD 7790 Turbo Duo is PCIe 3.0 compliant with backwards support of earlier specifications. At 8.25 inches long you will not find any challenges fitting this card into the chassis of your choosing.
Connectivity options include a pair of dual link DVI ports, a full size DisplayPort, and an HDMI port that supports HD audio, 1080p 120Hz 3D Stereoscopic support, and 4K resolutions. Eyefinity configurations using up to three screens is supported with the HD 7790. Gaming at 5760x1080 is not going to be possible without a second card. However using the large surface is truly of value in productivity applications. The back end of the card is not fully sealed allowing some of the airflow out of the shroud. A 6-pin PCIe power connection is used on the back end of the card. Flipping the card over we can get a batter idea of how the "Aerodynamics Kit" is implemented.
Additional performance can be gained by running the HD 7790 Turbo Duo in a Crossfire configuration with another HD 7790. At that price point it may make more sense to go for the single GPU card. Power requirements for the HD 7790 Turbo Duo call for a minimum power supply of 500 watts. A single 6-pin PCIe power connection is used to supplement the power supplied by the PCIe slot.
Stripped of the cooling solution you get a look at how the PCB and power solutions are configured. PowerColor uses its "Gold Power Kit" that includes a 4+1+1 phase power supply circuit, SVI2 Green Power Manage Technology, and SCP chokes. The VRM circuit uses a small but effective aluminum heat sink to keep the MOSFETs cool.
PowerColor's Turbo Duo cooling solution uses a pair of 80x10mm fans from Powerlogic to provide the airflow needed to shed the thermal load from the heat sink assembly. Equipped with 11 sickle-shaped blades, these fans push enough airflow to manage the thermal load. With the vBIOS managing the fan speeds the card is dead silent inside the chassis. Ramping them up to full speed makes them audible but nothing that is truly offensive.
The heat sink assembly mounts directly to the shroud holding it in place. Pulled out of the shroud the heat sink assembly uses an aluminum base and fin array. A single S-shaped direct contact heat pipe is used to transfer the thermal load to the fin array. The HD 7790 has an ~85 watt TDP so this solution should easily manage the thermals. Unfortunately this solution only addresses the memory with warm airflow after it has passed through the fin array.
AMD used a new revision of its Graphics Core Next architecture, codenamed Bonaire, on the HD 7790. This iteration is built on a 28nm process with 2.08 billion transistors under the hood. Specifications include 896 stream processors that handle two primitives per clock, 56 texture units, 16 ROPs, and 1GB of GDDR5 VRAM running through a 128-bit bus. A total of four memory ICs from Hynix are used that support speeds of up to 1500MHz. Baseline clock speeds from AMD are 1GHz on the GPU core and 1500MHz on the GDDR5 memory. PowerColor massaged the Turbo Duo to get a boost clock of 1075MHz but kept the memory at its rated specifications of 1500MHz.
If the performance of Sapphire's card is an indication of where the clock speeds will perform, then PowerColor's HD 7790 Turbo Duo should prove just as adequate in the FPS department.