IQ Comparison

Before we bring you the screenshots, first a caveat, due to the nature of the game, we can’t present you 100% identical screenshots. This is because in the game, nothing stands still: your character’s hands bob up and down while standing still, and the game world is always changing. A gust of wind for instance, may blow dust and debris across the game’s landscape, trees and other foliage sway in the breeze, or perhaps a mutated dog will come out of nowhere to attack you. The environment inside STALKER truly is a living, breathing world. In other words, nothing truly sits still to pose for an identical screenshot. You may see haze that isn’t as thick in one screenshot from the next, or characters may be slightly out of place, just ignore it.

Another thing about S.T.A.L.K.E.R. that you’ll soon see in the screenshots is that anti-aliasing doesn’t play as critical a role as it does in most other contemporary games. The developers have done a good job at keeping the jaggies in check without AA turned on. This is a good thing because turning on AA, whether via the game’s settings menu (or the user.ltx file) or the graphics driver control panel, AA has little or no affect on image quality. Considering the game’s usage of HDR lighting, we weren’t too surprised to see the GeForce cards lack of AA, but we did expect the Radeon X1K cards to work properly. Oh well, here are the screenshots as proof:

Radeon X1950 Pro 0xAA

Radeon X1950 Pro 0xAA

GeForce 7950 GT 0xAA

GeForce 7950 GT 0xAA

The shots above were taken with a Radeon X1950 Pro 256MB PCIe and a GeForce 7950 GT 512MB with AA disabled. You can clearly see the jaggies on the bottom of the window sill in the first test image, and along the front edge of the house (just above the ladder) in the second. Now let’s see what happens when we turn on AA in the game’s menu:

Radeon X1950 Pro 4xAA

GeForce 7950 GT 4xAA

In our first test area, the jaggies seem slightly smoother on both the ATI and NVIDIA cards under 4xAA (to our surprise in the case of the GeForce 7950 GT), but they’re still notably present. We should note that forcing 4xAA in the driver control panel didn’t improve things in this test case. Let’s look at our second test area:

Radeon X1950 Pro 4xAA

GeForce 7950 GT 4xAA

Woah, the jaggies on the front edge of the house are still there. In fact, it doesn’t look like they’ve been touched at all by either card! Let’s see what happens when you force AA via the driver control panel.

Radeon X1950 Pro 4xAA

GeForce 7950 GT 4xAA

Normally when you force AA via the driver control panel, the driver automatically applies AA to everything in the scene, overriding the game’s AA mode by default. But forcing AA doesn’t appear to affect anything at this point in S.T.A.L.K.E.R., as the jaggies on the front edge of the house are still present.

Again, considering that the GeForce 7 cards lack support for HDR+AA, we weren’t surprised to see that AA isn’t functioning 100% in S.T.A.L.K.E.R, but we did expect the Radeon X1K cards to run AA with HDR. For further analysis we’ve run performance numbers with the game running 0xAA, 4xAA via the game’s menu, and 4xAA forced via the driver control panel. In theory, we should get the highest performance numbers with 0xAA, and the slowest fps with 4xAA forced via the control panel, let’s see what happens.

UPDATE 3/28/07: We received the following from NVIDIA: "The trouble is not HDR+AA but rather the game's deferred shading engine which is fundamentally incompatible with hardware MSAA. Essentially it's the same issue as Ghost Recon Advanced Warfighter's engine. This is why the developer implemented a shader based AA (the slider in the game) but as you noticed, its effect is quite subtle. We have a new driver coming which gives some perf improvements and SLI for G80. Will keep you posted!"