Upgraded a rig recently to play Battlefield 3 and video capturing purposes with this Sapphire Radeon HD 6950. It wasn't a bad choice. Sapphire threw in as alwasy great support for all monitors and included 2 VGA/DVI converters although I did use the HDMI port.
The card is sbustantially longer (larger) than mid-range ones like 6870 or 6850 and will typically require a roomy case. It is also a dual slot cooling solution so it is quite bulky. Installation under Windows is typically easy; ensuring all your previous drivers have been uninstalled and the card put into place and system reboot.
One of the problems or annoyances you may face is the very audible humming when windows loads up due to the fan being sped up at the start. However with the correct drivers this will go down if the fan speed is set on auto - or on manual. At 40-50% fan speed typical idle temperature is at around 45 degrees or less.
So how does it perform in games and video capturing? Well for starters this is a 2GB part but not many games take advantage of this huge ram size. However, games like Battlefield 3 do feel very smooth when texture quality and anti-aliasing(AA) and anisotropic filtering(AF) are all maxed out. Running a tool like Fraps which captures raw video and at 1080p is capped at 60FPS - a more than adequate and playeable frame rate (while capturing raw video).
The card can get a little hot after a long gaming session and is obviously expect. It can also become a bit noisy if set on auto fan speed. At 50% it plays games at a round 55 degrees and is quite decent on the ears - especially if you happen to have headsets (which is likely).
There are less expensive cards out there that will perform enough to play Battlefield 3 and COD MW3 at high details but they may struggle with video capture. So if you are like me and do both gaming and video capturing - this card is ideal. However, if you just want a decent frame rate and play these games smoothly, skip the Radeon 6950 - its not worth it.
Do not get confused by the name. AMD made a rather poor name change move from the 4xxx series of cards to the 5xxx, and an even worse change to the 6xxx.
If you are expecting this thing to blast the 4xxx's and 5xxx's out of the water, and compete with the big boys at Nvidia, think again. I will save you the time of checking all the performance comparison websites, the 5xxx series is a meagre step up from the 4xxx's, and this latest series is in actual fact, a surprise step down.
In order to capture the lower end, casual user's attention, AMD released it's 6xxx series graphics cards. They are all DirectX 11 ready, and have an appealing new name. If you were to name these cards relative to their older counterparts, they would be the 53xx-58xx's.
This specific card does have some power under its belt, it is at the top end of its respective series, and boasts an impressive 2GB of on-board memory, and three monitor outputs (discussed in more detail further down). Unfortunately, having attempted to create a "high-end" card for a low end market, AMD has simply ended up creating an underpowered mid-level card. It can play any game, certainly not on the highest settings, even with that extra memory.
Just in case you have a see through case, or want to dream about the card inside your machine, rest assured, even if you cannot see it, the card is making your case look good. This is a beautiful looking piece of kit, and that is coming from an Nvidia fan boy.
Heat and Power
Cool in comparison to previous AMD series', and only using 20 Watts more than an HD 4850, with the new total system weighing in at 200 Watts, the HD 6950 is really quite impressive. It has a very high performance to energy usage ratio, and also a very good 'bang for buck' ratio, to borrow an American term.
Anything to be aware of?
You must understand your intended usage for the new card you want, and the desired improvement to your current system. For instance, upgrading from a n HD 5850 is pointless for the money spent, you really will not notice a difference. For a minimum two times improvement in games, an upgrade could be considered from a GTS 450, or HD 5750. Whatever excellent performance boosts you can gain from this card, be very wary of what you actually need, in reference to video editors, consider spending that extra £50 to get a higher performing model, which may well reduce to time you have to wait for work to render significantly.
Note: I rate relative for the type of user I expect to be considering the product, hence, a high end card, and a mid-level card can both receive 5 stars.