Review: Quiet as a breeze, strong as storm
Gigabyte has been busy as of late improving its existing graphics card coolers and designing new ones. Our today’s guest is the company’s HD 7850 OC graphics card, notable for Gigabyte’s WindForce 2x cooler, which promises silence even when the card is working hard. That Gigabyte is ready for non-conventional designs is clear from its GTX 680 Super Overclock card, which comes with five fans and nine heatpipes, but more on that on another occasion.
The card’s name, HD 7850 OC Windforce 2x, says it’s a factory overclocked card. The GPU has been overclocked by 115MHz but the memory was unfortunately left at reference 1200MHz (4800MHz GDDR5). We’ve noticed that many overclocked AMD and Nvidia cards come with overclocked GPUs but reference memory clocks. We’d much rather see overclocked memory because users who buy overclocked cards usually don’t want to mess with any further overclocking, i.e. want their pet juiced out straight out of the box, and quite understandably so.
Gigabyte HD 7850 OC WindForce 2x is on the picture below.
We’re sure you want to know more about WindForce, but before we move onto that part, let us say something about the HD 7850 first.
HD 7850 as well as HD 7870 is equiped with 2GB of memory on a 256-bit memory interface, which will be of much use to gamers running 1920x1080.
Compared to Pitcairn XT (HD 7870), Pitcairn Pro comes with lesss shaders (1024 compared to XT’s 1280), and less texture units (64 compared to XT’s 80). Both GPUs come with 256-bit memory interface and 30 ROPs each. HD 7850 launched priced at $249, while HD 7870 cost $349. AMD set the reference clocks for Pitcairn XT at 1000MHz and Pitcairn Pro to 860MHz.
The factory overclock is the culprit for higher GPU temperatures, but the card comes with powerful WindForce 2x cooler, a cooler with two 10cm fans.
Each fan makes an airflow of 30.5 CFM. The fans exceed the PCB boundaries but in this case it’s a good thing since they cool heatpipes that stick out beyond the PCB. The heatpipes are in direct contact with the GPU.
One of the secrets to quality cooling is that the fans and the heatsink are angled. You can’t tell this at a glance, but once you look at the card from the side, you’ll see for yourself. The angle lowers the turbulence between the two fans.
Although the plastic frame seems a bit shaky, it’s actually quite stable.
By using low profile fans, Gigabyte made sure that the cooler does not exceed two slots. HD 7850 OC WindForce is about 227mm long and about 120mm tall.
Both fans are on the same power cable and you can manage RPM via any standard tool, including AMD Overdrive. Note however that Auto regulation worked just fine, so we just left it as it is.
The card uses 4-phase VRM design, with GIGABYTE's Ultra Durable 2 combination of Solid State Capacitors, Ferrite Core chokesandlow RDS(on) MOSFETs.
Gigabyte 7850 TwinForce card is equipped with 2048MB GDDR5 memory. The GDDR5 memory chips are made by Hynix (model number H5GQ2H24MFA-T2C). They are specified to run at 1250MHz (effective 5000MHz). The chips are cooled by fan air only.
The reference design provides two mini DisplayPort 1.2 connectors, HDMI and a single dual-link DVI out, and the seme setup is used on Gigabythe's card. HDMI 1.4a provides HD audio and supportfor Blu-ray 3D movies. It will simultaneously support three displays, although the third display must be connected via DisplayPort.
You may combine the Gigabyte's 7850 TwinForce card with another HD 7850 card from any vendor in CrossFire. Flexible CrossFire bridge helps with reaching the connectors, even though the plastic shroud is in the way.
The card is powered via one 6-pin power connector, which is easily accessible thanks to the cutout in the heatsink.
Motherboard: EVGA X79 FTW
CPU: Sandy Bridge-E Core i7 3820 (3.6GHz)
CPU Cooler: Thermalright HR-02 (Thermalright-Europa Distri www.PC-Cooling.de).
Memory: 8GB ADATA DDR3 1600 XPG Gaming series
Harddisk: OCZ Vertex 2 100 GB
Power Supply: CoolerMaster Silent Pro 1000W
Case: CoolerMaster Cosmos II Ultra Tower
Operating System: Win7 64-bit
Aliens vs Predator
Tessellation: Unigine Heaven
Gigabyte HD 7850 OC TwinForce 2x graphics card is a factory overclocked card, whose GPU was boosted by 115MHz but the memory left at reference 1200MHz (4800MHz GDDR5). We managed to overclock the GPU higher, to 1025MHz.
We expected a better overclock since the cooler does its job great. GPU temperatures didn’t exceed 56°C at factory clocks, while our overclocking increased them by a single degree Celsius. We left the fan in AUTO mode durin our overclocking because thermals were good and the fan quiet. Increasing the RPM manually didn’t provide for a better overclocking score.
We left the memory at 1200MHz because even the slightest boost of 50MHz caused our system to freeze. In fact, not even a system restart managed to help on few occasions, and we had to resort to throwing in another card and clearing the drivers.
As far as noise goes, fans are inaudible. We didn’t hear them until they exceeded 70%RPM (which was never the case in AUTO mode). When the fans exceed 70%RPM, you’ll hear a very faint buzzing noise. We’re not sure what’s the cause, but it’s most likely the fan vibration causing parts of the heatsink to vibrate as well. Note however that it’s far from loud – in fact, you won’t hear it away from the computer and pretty much never in AUTO fan mode.
Gigabyte HD 7850 TwinForce 2x’s consumption was quite good. Our rig drew up to 240W, which is less than some slower cards from earlier generation. Although we’re looking at a factory overclocked card, Gigabyte made sure that the TDP doesn’t go over 130W.
Gigabyte Radeon HD 7850 OC WindForce 2x (GV-R785OC-2GD) graphics card surprised us with just how quiet it is, whether it’s idle or working hard. Although it’s a graphics card with a 115MHz GPU overclock, WindForce 2x has no trouble keeping it cool and temperature didn’t go over 56°C.
Overclocking results are below average. We could overclock the GPU only up to 1025MHz, while the memory started misbehaving after only 50MHz extra.
Once the fan is sped up over 70%RPM, you’ll hear a strange noise from teh fan, as if the fan occasionally touches some part of the heatsink, but we couldn’t really tell exactly. When running in AUTO mode, the fan never hits 70%RPM, so it will always stay quiet.
Despite such OC results, we really think Gigabyte’s HD 7850 OC WindForce 2x deserved to get our award, since it’s overclocked but silent. The GPU was overclocked from reference 860MHz to 975MHz while the WindForce 2x cooler makes sure to keep it cool. Performance is excellent for gaming at 1680x1050 and 1920x1080.
Gigabyte’s card is some €10 pricier than the most affordable HD 7850, which is definitely justified. So, if you’re looking for an overclocked card with quiet cooling, there’s no reason to overlook Gigabyte’s HD 7850 OC WindForce 2x.