AMD Radeon 6850 Bottleneck Investigation

Introduction

Welcome to the latest installment of my ongoing investigation on bottlenecking with video cards. For those not familiar with the series, I underclock one part of the video card while leaving the other part(s) at stock to see which affects performance the most.

Here are the past articles in the series:

• nVidia GTX470.
• ATi 5770.
• nVidia GTX285.
• nVidia GTX260+.
• nVidia 8800 Ultra.

For this article I will be testing a Radeon 6850 with a 20% underclock to the core and memory (when one is underlocked, the other stays at stock). Since stock speeds for a 6850 are 775/1000 (core/memory), a 20% underclock is 620 core and 800 memory.

Hardware

• Intel Core i7 870 (3.2 GHz, turbo on, HT off).
• 4 GB DDR3-1333 RAM (2×2 GB, dual-channel).
• Gigabyte GA-P55-UD3 (Intel P55 chipset, F6 BIOS).
• AMD Radeon 6850 (1 GB), reference clocks.
• Creative X-Fi XtremeMusic.
• 30” HP LP3065.

Software

• Windows 7 (64 bit).
• AMD Catalyst 10.12, high quality filtering, surface optimization disabled.
• DirectX June 2010.
• All games patched to their latest versions.

Settings

• 16xAF forced in the driver, vsync forced off in the driver.
• AA forced either through the driver or enabled in-game, whichever works better.
• Highest quality sound (stereo) used in all games.
• All results show an average framerate.