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FX Vs. Core i7: Exploring CPU Bottlenecks And AMD CrossFire

Test Settings And Benchmarks

We began our testing with an older boxed Core i7-3770K as we waited for the FX-8350 we purchased. Relatively certain the AMD processor would hit at least 4.4 GHz without thermal issues, we started off Intel's processor at the same clock rate. Later, it became clear that our estimate was too conservative, as both CPUs exceeded 4.5 GHz at our chosen voltage levels.

Retesting at higher frequencies would have further delayed this story, so we stuck with 4.4 GHz on both the Intel and AMD chips, at least in the clock-matched portion of our benchmarking.

Test System Configuration
Intel CPUIntel Core i7-3770K (Ivy Bridge): 3.5 GHz, 8 MB Shared L3 Cache, LGA 1155 Overclocked to 4.4 GHz at 1.25 V
Intel MotherboardAsus Sabertooth Z77, BIOS 1504 (08/03/2012)
Intel CPU CoolerThermalright MUX-120 w/Zalman ZM-STG1 Paste
AMD CPUAMD FX-8350 (Vishera): 4.0 GHz, 8 MB Shared L3 Cache, Socket AM3+ Overclocked to 4.4 GHz at 1.35 V
AMD MotherboardAsus Sabertooth 990FX, BIOS 1604 (10/24/2012)
AMD CPU CoolerSunbeamtech Core-Contact Freezer w/Zalman ZM-STG1 Paste
RAMG.Skill F3-17600CL9Q-16GBXLD (16 GB) DDR3-2200 CAS 9-11-9-36 1.65 V
Graphics2 x MSI R7970-2PMD3GD5/OC: 1010 MHz GPU, GDDR5-5500
Hard DriveMushkin Chronos Deluxe DX 240 GB, SATA 6Gb/s SSD
SoundIntegrated HD Audio
NetworkIntegrated Gigabit Networking
PowerSeasonic X760 SS-760KM: ATX12V v2.3, EPS12V, 80 PLUS Gold
OSMicrosoft Windows 8 Professional RTM x64
GraphicsAMD Catalyst 12.10

Great performance and quick installation have kept Thermalright’s MUX-120 and Sunbeamtech’s Core Contact Freezer on my shelf for several years. The brackets that came with these older samples make them non-interchangeable, however.

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G.Skill’s F3-17600CL9Q-16GBXLD has a remarkable DDR3-2200 CAS 9 rating, using Intel XMP technology for semi-automatic configuration. As a non-Intel platform, the Sabertooth 990FX configures XMP values through Asus' DOCP setting.

Seasonic’s X760 provides the consistent efficiency required to assess platform power differences.

StarCraft II doesn’t support AMD's Eyefinity technology, so I looked at the recent work of our other editors before bringing back a few classics in today’s test: Aliens vs. Predator and Metro 2033.

Benchmark Configuration (3D Games)
Aliens vs. PredatorUsing AvP Tool v.1.03, SSAO/Tesselation/Shadows On Test Set 1: High Textures, No AA, 4x AF Test Set 2: Very High Textures, 4x AA, 16x AF
Battlefield 3Campaign Mode, "Going Hunting" 90-Second Fraps Test Set 1: Medium Quality Defaults (No AA, 4x AF) Test Set 2: Ultra Quality Defaults (4x AA, 16x AF)
F1 2012Steam version, in-game benchmark Test Set 1: High Quality Preset, No AA Test Set 2: Ultra Quality Preset, 8x AA
The Elder Scrolls V: SkyrimUpdate 1.7, Celedon Aethirborn Level 6, 25-Second Fraps Test Set 1: DX11, High Details No AA, 8x AF, FXAA enabled Test Set 2: DX11, Ultra Details, 8x AA, 16x AF, FXAA enabled
Metro 2033Full Game, Built-In Benchmark, "Frontline" Scene Test Set 1: DX11, High, AAA, 4x AF, No PhysX, No DoF Test Set 2: DX11, Very High, 4x AA, 16x AF, No PhysX, DoF On
Thomas Soderstrom
Thomas Soderstrom is a Senior Staff Editor at Tom's Hardware US. He tests and reviews cases, cooling, memory and motherboards.