Introduction Just before Christmas AMD released their much hyped Cayman series of GPU's. So far the family consists of the 2gb Radeon HD 6950 and 6970. In the last week of January, AMD has released a simplified 1gb version of the 6950 as well. It was hoped the cards would get their nose in front of the newly released revised Fermi cards from Nvidia. Whilst they couldn't match the performance of the Nvidia cards, they did come with a more attractive price and a unique feature set. Shortly after the release, adventurous users attempted to flash a reference 6970 bios to a reference 6950 card and found the procedure unlocked the full complement of 6970 shaders. That brings me to the topic of todays review, which will focus on the ability to unlock the R6950 to a 6970 and making a performance comparison between the two. A look at the MSI R6950 First lets have a look at the card. The MSI R6950 is based on the reference AMD design, featuring a Cayman GPU with 1408 shaders clocked at 800mhz. It is built with TSMC's mature 40nm process containing 2.64 billion transistors. The frame buffer is a huge 2gb of GDDR5 clocked at 1250mhz for an effective 5ghz clock. That much memory is enough for high levels of AA and AF and game texture mods even with Eyefinity setups. Full specifications and R6950 info can be found at the MSI website here. The adapter on the right is a mini display port to display port adapter. On the left of the crossfire connectors is the switch to change between bios'. Flashing the R6950 to 6970 Despite the ridiculous ease of the flashing process, I must give a compulsory disclaimer. This is for 2GB REFERENCE CARDS ONLY. Don't do it if you don't know what 6950 card you have. Always make sure your system is 100% stable before attempting any bios flash. When I unlocked this card, several steps were involved, however thanks to the much respected guys at Guru3D and Techpowerup it has been made ridiculously easy.. as in one mouse click. Click the clearly named batch file and voila: Hello 6970. The following download contains the required tools and bios. For convenience, the reverse procedure is also included, to bring the card back to a standard 6950. Honestly it doesn't get any easier. The bundle with batch file and included bios' can be found here AMD has made things quite safe thanks to the inclusion of a dual bios on Cayman cards. This means that if the procedure goes wrong (unlikely), the card is not bricked, but can be restarted with the backup bios and the flash reversed. Flashing the card with a default 6970 bios brings the card to 1536 shaders clocked at 880mhz and ups the memory clock to 1375mhz for an effective 5500mhz. The result is a 10% higher GPU and memory clock and as well as the extra shaders. It seems all reference 2gb 6950's can be unlocked to a 6970 and the vast majority will run at the default 6970 clocks. Should you be one of the very few who gets rendering errors with the default 6870 bios, there are two options. Either down clock the card or use a bios that unlocks the shaders but leaves the default 6950 clocks. MSI's leading Afterburner application features full support for the R6950 and R6970 in the latest beta but not a flashed 6950. Thankfully there is a way around this with a little legwork. To get overvoltage support enabled, you must open a peculiarly named file in the profiles folder typically found in C:/Program files (x86)/MSI Afterburner/Profiles/ What you need to do is open the file with notepad, and add the following after the last line. [Settings] VDDC_VT1556_Defaults = 9A 5C 9B 80 It should now look like this: Save and exit. Afterburner will now overvolt the card Before and after: Benchmarks Test Setup: Intel i7 980x @ 4.2ghz MSI BigBang Xpower motherboard MSI R6950 2PM2D2GD5 (Catalyst 11.1a Hotfix beta) 3x2gb Kingston 2250mhz 9-11-9 @ 1824mhz 6-9-6-24 Thermaltake Toughpower 1200w Windows 7 64bit The following benchmarks are run at 3 settings. They are a 6950 in its default configuration with 1408 shaders @ 800/1250, second with the card unlocked to the full 1536 shaders at 800/1250 and finally as a 6970 with 1536 shaders @ 880/1375. The game benchmark results below show the average FPS whilst the synthetic benches show the overall score. The benchmarks show the benefit of the 1536 vs 1408 shaders, but perhaps not as much as expected. Whats interesting is the gain coming from the increased clocks is larger in all benchmarks. The extra bandwidth may be significant which I will be interested in testing further. Conclusion The Radeon HD 6950 is already a well priced, solidly performing card, but the 'free' upgrade to a 6970 makes it even better value for money. Over time drivers should improve as the Catalyst team learns to maximize the efficiency of the new VLIW4 architecture. It has the grunt for the latest DX11 titles at high resolutions. It has HDMI, DP/mini DP, DVI and VGA via adapter taking care of all display connectivity. It comes with very low idle power consumption which shouldn't be underestimated as a feature. The dual bios feature more or less removes the chance of bricking the card with a bad flash and since the card is from MSI, you also get the class leading Afterburner utility. AMD's strategy in recent years has been to hit the sweet spot with regards to performance/price. Chalk up the 2gb 6950 as another successful result of that strategy. Pros: Unlocking ability Attractive pricing MSI Afterburner utility Range of outputs and Eyefinity Low power consumption, particularly at idle Cons: Runs quite hot A touch noisy (Australian summer doesn't help) Thanks to MSI Australia for the review sample.