A Closer Look at the MSI HD 7970 Lightning
A Closer Look at the MSI HD 7970 Lightning
MSI’s Lightning cards have always been a class apart not only terms of features but also their sheer size. This one is no exception since it nearly 12” long and a massive 5” wide due to an expanded PCB. The width shouldn’t be an issue for most end users since enclosures typically have more than enough breathing room between the motherboard and their side panel. Length however could be an issue since some smaller ATX cases don’t have 12” to spare.
As one might expect, MSI has decked this card out with their highest performing heatsink. The Twin Frozr IV uses a pair of 100mm PWM fans featuring Dust Removal technology to keep their bearings in top shape and specialized blades that are supposed to boost airflow by up to 20%. Due to this massive amount of air movement, the heatsink below comes equipped with five 8mm heatpipes that quickly whisk heat away from the core, to be dispersed within the aluminum fin array.
The main cooling assembly has been combined with what MSI terms a “Form in One” unit that consists of front and rear mounted secondary heatsinks. The job of these is to efficiently cool down the memory, PCB and VRM components under situations of heavy load or high frequency overclocking.
There’s also a GPU BIOS switch hiding under the shroud which can be moved over into its secondary position to disable the OCP, increase the Power Tune limit in MSI’s Afterburner tool and increase the overclocking range.
Flipping the Lightning over reveals the aforementioned Form in One black anodized aluminum heatsink along with a patented feature called the GPU Reactor.
While its name may elicit some snicker from certain enthusiast circles, the GPU Reactor does have its uses. According to MSI, attaching this add-on PCB to the area directly behind the GPU core is supposed to provide additional power capacity in order to ensure maximum stability when overclocking. To achieve this, the Reactor leverages the Lightning’s advanced VRM grid in order to selectively boost current to the core when need while virtually eliminating voltage fluctuations. This certainly is an interesting concept and judging by the impressive clock speeds these cards have been achieving when placed into the right hands, the GPU Reactor seems to be doing its job. However, if you plan on overclocking within the limits of air cooling, we highly doubt you will see any benefits from this inclusion.
With connectors sprouting up all over this card, it was good to see that MSI had at least included dual 8-pin power inputs but unlike other designs, the way these are handled is quite unique. Instead of haphazardly dictating where the incoming power is directed, the Lightning dedicates a single 8-pin exclusively for powering the GPU core while the other is used for memory current.
Not only does this setup ensure that power for the primary components is pulled through the PCI-E bus but it also lowers ripple which in turn should help with long term stability.
As is par for the course with high end MSI cards, the Lightning has a trio of voltage monitoring ports. With the included break out wires, you can use a multimeter to measure GPU, memory and VDDCI readings.
When in use, the Lightning puts on a bit of a light show with numerous blue LEDs on the PCB’s underside. The long bank of lights indicates the number of power phases being used while the GPU Reactor stays illuminated provided the extra PCB has been installed.
We don’t usually concentrate all that much upon a card’s output connectors since nearly all of them tend to stick with the reference design. MSI on the other hand took the path less travelled and ended up with a seriously mixed bag of results.
The four included mini DisplayPort 1.2 connectors and dual DVI outputs guarantee the Lightning is compatible with up to six simultaneous displays….but not so fast. First and foremost, only a single passive mDP to full DP adaptor is included so this card doesn’t natively support six displays without an additional layout of money.
MSI’s nickel and diming with adaptors isn’t even the most egregious error here either. The two single link DVI connectors take that prize by a long shot. To anyone with a 1920 x 1200 or lower resolution monitor, this won’t be a big deal but if you are like us and have a high quality 2560 x 1600, 2440 x 1440 or 120Hz display without DisplayPort, be prepared to pony up an additional hundred bucks or so for an Active DisplayPort to Dual Link DVI adaptor. Without it, your ultra expensive monitor will be rendered useless by the Lightning.
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