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 Testing and Overclocking: To test the 4850, we are going to be using a similar methodology as the 3850 review. For the synthetic benchmarks, we are using 3DMark06 and 3DMark Vantage for both stock and overclocked speeds. For the game tests, we are going to run Crysis 1.2.1 and Call of Duty 4 v1.6 through several different resolutions and settings at stock speeds. All testing has been done with the Catalyst 8.6 driver with the recently released hotfix that promises to improve performance and stability. For added thrills, I have also done some experimenting with the GPU2 calculation tool used for Folding@Home.
To overclock the 4850, I was resigned to using the built in Auto-Tune function in the Catalyst drivers, as most of the common overclocking tools do not have support for the 4850 as of yet. Auto-Tune maxes out at 700MHz on the core and 1200MHz on the memory, so if this card is capable of exceeding those numbers, we are just going to have to wait for third party support. Using the Auto-Tune, it came up with maximum clocks of 690MHz on the core and 1133MHz on the memory. However, further testing revealed some stability issues, so I ended up settling with 680MHz on the core and 1025MHz on the memory, resulting in a 8.8% and 3.2% overclock, respectively. Not exactly huge, but we will get into why that is likely the case later. Our first test is what is essentially the ultimate punisher of graphics cards: Crysis. Conveniently, there is a really handy Crysis benchmark tool, known as (oddly enough) "Crysis Benchmark Tool". This tool allows us to setup multiple runs in advance, run them all with a single push of a button, and then spit out the results in a Microsoft Word Document. We test the 4850 at 1280x1024, 1680x1050, and 1920x1200, using 0xAA, 2xAA, 4xAA, and running each of those at both High and Very High settings, for a total of 18 tests. The test was run with the 1.2.1 patch for Crysis.
Even though the 4850 fared better than the 3850 in Crysis, it does not change the fact that Crysis still pretty well brutalized the card. At 1680x1050, with no AA and bilinear AF, the card is still playable at "High" settings. Anything beyond that, and you will need to start turning down settings. The next game in our benchmark list is the ever popular Call of Duty 4. Call of Duty 4 may not represent the best in DirectX 10 goodness, however the game is still visually stunning, and being as popular as it is, it is not hard to justify running it. To measure framerate in Call of Duty 4, I used the FRAPS benchmarking tool, which allows me to log framerate against time. I used the "Shock and Awe" single player mission, from the beginning until you land the chopper. I chose this mission due to the ease of replicating this section of the game over several tests. All settings are set to maximum quality unless otherwise noted.
The first test I ran for CoD4 was what I figured to be the "best case" scenario for the 4850. 1280x1024 is generally considered the lowest gaming resolution played these days, as dictated by the many 19" LCD panels on the market. Here the 4850 did very well, with a minimum framerate of 42fps, a max of 135, and an average of 88fps.
Another common resolution for modern flat panels is 1680x1050. Here we tested with no anti-aliasing and bilinear AF. The performance here was nearly identical to the first test, with a minimum framerate of 41fps, max of 122, and an average of 78fps.
At this same resolution, I tested again, this time with 4x anti-aliasing and maximum trilinear anisotropic filtering. In this case, we see a minimum of 32fps, a max of 91, and an average of 57. Still very playable.
Just to crank things up another notch, I also tested the 4850 at what is considered the top end resolution for most gamers, 1920x1200. In the above test, without AA and bilinear AF, we get a minimum framerate of 37fps, a max of 107fps, and an average of 69fps.
Finally, I let out all the stops and maxed out everything I could, and here is how it did: 21fps minimum, 83fps max, and an average of 51fps. Here we are just touching on the very edge of the limit; the 4850 is still mostly playable at these settings. Not bad at all for a "mid-range" card.
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