This time last year Valve launched an unusual gaming title called Left 4 Dead, which was a cooperative first-person shooter that allowed a bunch of players to run around killing zombies. Now exactly a year later we have the sequel, Left 4 Dead 2. This game builds upon the cooperatively focused game-play of the original and uses Valve's proprietary Source engine, the same game engine used by the original.

Also like the original, Left 4 Dead 2 is set during the aftermath of an apocalyptic plague and focuses on four survivors who take on the infected. These survivors must fight their way through levels, mix together with safe houses that act as checkpoints, with the goal of reaching a rescue vehicle at the campaign's finale.

The game-play is altered by an artificial intelligence engine dubbed the "Director", that monitors the players' performance and changes the scenario to provide a dynamic challenge for the players as they progress. Many of the games changes, or improvements if you will, do not come from the game engine itself. Rather Valve has just added new types of infected, melee weapons, and a story-arc that connects each of the game's five campaigns together.

Given that just 12 months have passed since the release of the original Left 4 Dead game, it is hard to believe that there will be anything really new in the second installment in terms of graphics. While this is not entirely bad news, it will mean that gamers are paying full price for what almost seems like an expansion pack to us, all be it a very big one.

Having said all that, the game has attracted an unusually high volume of pre-release controversy from the gaming community. Many die hard Left 4 Dead fans were upset that Valve began working on this new title right away, and felt betrayed that Valve did not deliver on all the downloadable content that they had promised. In the end Valve did promise that despite releasing a new version of Left 4 Dead, they would continue to update the original.

Although personally I never got into Left 4 Dead, it does seem like a very fun game and I certainly understand its popularity. Since its release we have used this game to benchmark a range of hardware, namely graphics cards. Therefore, given that we are familiar with the performance of the original and will likely include Left 4 Dead 2 in our list of games used to test future graphics cards, we thought it prudent to introduce it with a performance article.

This new game has only been tested using maximum graphics quality settings, with the AA/AF levels cranked right up. The latest official drivers were used for all graphics cards, which saw both Crossfire and SLI working correctly.

For measuring frame rates we relied on FRAPS, where we recorded 2 minutes of gameplay from the Waterfront level. There was plenty of action going down that made for an ideal place to test these GPUs. We also overclocked our Core i7 965 EE processor to 3.7GHz in an attempt to remove any CPU bottlenecks that could influence high-end graphics cards scores.

We will be looking for an average of 60fps for stutter-free gameplay.

Hardware - Intel Core i7 965 Extreme Edition (Overclocked @ 3.70GHz) - x3 2GB G.Skill DDR3 PC3-12800 (CAS 9-9-9-24) - Seagate 500GB 7200-RPM (Serial ATA300) - Inno3D GeForce GT 220 (1GB) - Asus Radeon HD 3850 (512MB) - HIS Radeon HD 4670 (512MB) - Asus GeForce 9600 GT (512MB) - Asus GeForce 9800 GT (512MB) - HIS Radeon HD 4850 (512MB) - HIS Radeon HD 4770 (512MB) - HIS Radeon HD 5750 (1GB) - HIS Radeon HD 4870 (1GB) - HIS Radeon HD 5770 (1GB) - HIS Radeon HD 4890 (1GB) - Asus GeForce GTX 260 (896MB) - Asus GeForce GTX 275 (896MB) - AsusGeForce GTX 285 (1GB) - HIS Radeon HD 5850 (1GB) - HIS Radeon HD 5870 (1GB) - HIS Radeon HD 5770 (1GB) Crossfire - Asus Radeon HD 4870 X2 (2GB) - Asus GeForce GTX 295 (1792MB) - ASUS P6T Deluxe (Intel X58) Software - Microsoft Windows 7 Ultimate (64-bit) - Nvidia Forceware 191.07 - ATI Catalyst 9.10

Ideally we are looking for an average of at least 60fps to ensure consistently smooth game-play. Even with maximum in-game quality settings in use with 8xAA/16xAF we found that graphics cards such as the Radeon HD 4770 were able to break the 60fps barrier at 1680x1050. The GeForce 9800 GT dipped below this critical target with an average of 54fps, while the 9600 GT averaged just 47fps.

Other graphics cards, such as the Radeon HD 4670, 3850, 4650 and that silly new GeForce GT 220, will all require the AA/AF quality levels to be significantly reduced if not turned off all together.

Then when looking past the Radeon HD 4770 we have the 4850 which averaged 70fps and the 5750 with 72fps. The slightly more powerful Radeon HD 5770 managed 83fps, making it only a fraction slower than the GeForce GTX 260 which averaged 87fps. At the top of the graph we have the GeForce GTX 295 with 155fps, the Radeon HD 4870 X2 with 147fps, and the mighty Radeon HD 5780 with 146fps.

Increasing the resolution to 1920x1200 did the low-end cards no favors, and this time we see that the Radeon HD 4770 has dropped to 53fps. Even the Radeon HD 4850 managed just 59fps, while the Radeon HD 5750 did average 62fps. The GeForce 9800 GT was weak averaging just 44fps, while the 9600 GT was even slower with 38fps.

The Radeon HD 5770 proved to be an excellent value solution once again, with an average of 71fps, making it just 3fps slower than the GeForce GTX 260. The high-end cards again had no issues using these extreme visual settings, as the Radeon HD 5850 averaged 105fps while the previous single GPU king the GeForce GTX 285 still managed 92fps.

Naturally those that can afford a 30” LCD can probably afford the graphics card to go with it, so there is little chance those playing at this resolution will be doing so with a second rate graphics card. Nonetheless, it is interesting to see how the various graphics cards perform at 2560x1600. In short you can almost rule out anything under the GeForce GTX 275 which averaged 59fps. The Radeon HD 4890 averaged just 52fps, making it just a frame faster than the GeForce GTX 260.

The Radeon HD 5770 had also found its limit with an average of just 48fps. The GeForce GTX 285 hung in there with 64fps, while the Radeon HD 5850 was comfortable with 73fps. While one Radeon HD 5770 struggled, throwing two of them in a system using Crossfire meant that the average frame rate jumped up to an impressive 86fps. The Radeon HD 4780 X2 averaged 87fps, and the Radeon HD 5870 managed 88fps, while the GeForce GTX 295 cranked out 96fps for the win!

This is both good and bad news for fans. It means those still trying to get by using mid-range hardware, can enjoy Left 4 Dead 2 using maximum quality settings with modest AA levels. However for those that have recently lashed out on a new Radeon HD 5850/5870 graphics card, or own an impressive SLI setup, do not expect Left 4 Dead 2 to be a game that you can show your hardware off with.

Although I was unable to spend much time playing the original game, from what I did see the second installment does appear to be more polished. While the graphics are very much the same, the new types of zombies certainly add to the excitement. Furthermore the new animations and reactions of the zombies are greatly improved, which has made setting them on fire even more fun.

The new melee weapons will certainly appeal to fans, and it has to be said that there is certainly something about whacking zombies in the head with a frying pan that never gets old. Left 4 Dead 2 has already provided us with a great deal of entertainment in the few days that we got to play it, and we hope that the fans enjoy it as much as we did.

Additionally, we hope that this performance article, where we looked at maximum quality performance, helps to give you an idea of what your graphics card is or isn’t capable off. The game will officially be available for purchase very shortly, so we suggest you get your hands on it and enjoy the mayhem. Sadly for us we have to move on, as AMD and Nvidia are releasing new products this week which will see an end to our gaming for the time being...

Reviewed By Steven Walton