In open scenes of the game the frame rate is not higher than 62-64fps, being obviously limited by the system’s CPU.
The GeForce GTX 280 is the weakest card in this category. Although it delivers comfortable performance at any resolution up to 1920x1200 inclusive, it is up to 25% slower than the ATI Radeon HD 4870 X2. You can improve performance by adding a second such card in SLI mode, but the result wouldn’t be worth the trouble and money unless you’ve got a monitor that can work at a resolution of 2560x1600 pixels.
There is no sense in building a 3-way CrossFire subsystem due to the above-mentioned limitation on the CPU part. Such a subsystem wouldn’t be able to show its best in a PC configuration similar to our testbed.
The choice between the GeForce 9800 GTX and Radeon HD 4870 X2 is not obvious in the previous price category just because the latter is more expensive and has higher power consumption, but it is all clear here. The Nvidia GeForce GTX 260, in its classic version with 192 shader processors, has no chance against the ATI Radeon HD 4870 1GB. We didn’t have a sample of the newer GeForce GTX 260 (with 216 active shader processors) for this test session, but we doubt the additional 24 ALUs would make the GTX 260 competitive to the ATI Radeon HD 4870 that has as many as 800 ALUs. Nevertheless, it still can deliver acceptable gaming speed at a resolution of 1920x1200 pixels.
It’s clear that the highly detailed and vast environment of the game puts a heavy load on the graphics card’s memory subsystem. 4x MSAA contributes to this load, too. As a result, the Radeon HD 4850 falls far behind its elder brother even at 1680x1050 as it lacks fast GDDR5 memory. In this case it still delivers a comfortable level of minimal speed, however, in 1920x1200 it loses even to Nvidia GeForce 9800 GTX+. The latter performs fairly well despite its outdated architecture.
Summing it up, the Radeon HD 4870 1GB is the best choice in the performance-mainstream category for playing Fallout 3. Choosing between the Radeon HD 4850 and GeForce 9800 GTX+ is not easy because the former is only ahead at low resolutions. The older version of GeForce GTX 260 it is being very modest here: it shows considerably lower speed than ATI Radeon HD 4870 1GB, and although it boasts comparable power consumption it is much larger in size. There is not much sense in purchasing this card for playing Fallout 3 provided the prices are comparable.
There is one leader from the red team in the sector of mainstream gaming cards. It is the Radeon HD 4830. This graphics card enjoys an advantage of 15-16% over the opponent from the green camp, the GeForce 9800 GT, at 1280x1024. The gap shrinks to 7% at 1680x1050, probably because the memory subsystem bandwidth becomes the main limiting factor.
It is interesting to note that the GeForce 9600 GT, based on the modest G92 core with only 64 ALUs, is no worse than the more advanced G92-based card in both average or bottom speed. The rather old Radeon HD 3870 feels all right, too. The Radeon HD 4670 makes up for its narrow 128-bit memory bus with its advanced computing and texture-mapping capabilities. This simple, quiet, cold and inexpensive card is no worse than the GeForce 9600 GT and delivers a high level of comfort at 1280x1024, too.
So, the choice in the top mainstream segment is obvious. The Radeon HD 4830 is unrivalled here. The bottom mainstreams segment offers a wider choice as every product is worth the money asked. However, ATI’s solutions look preferable due to their more progressive architecture and advanced multimedia capabilities, including an integrated audio core.