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Gaming Performance Comparison

Recommended System Requirements
Game Radeon HD 6870 PowerColor 1GB Edition GeForce GTX 660 Direct CU II OC Edition
Cyberpunk 2077 297% 188%
Red Dead Redemption 2 189% 110%
Dragon Ball Z Kakarot 78% 30%
Halo: Reach 8% 33%
Microsoft Flight Simulator 297% 188%
Call of Duty: Modern Warfare 189% 110%
FIFA 20 54% 12%
Doom Eternal 149% 81%
Grand Theft Auto VI 342% 221%
Need For Speed Heat 189% 110%

In terms of overall gaming performance, the graphical capabilities of the Nvidia GeForce GTX 660 Direct CU II OC Edition are significantly better than the AMD Radeon HD 6870 PowerColor 1GB Edition.

The GTX 660 has a 120 MHz higher core clock speed and 24 more Texture Mapping Units than the HD 6870. This results in the GTX 660 providing 31.2 GTexel/s better texturing performance. This still holds weight but shader performance is generally more relevant, particularly since both of these GPUs support at least DirectX 10.

The GTX 660 has a 120 MHz higher core clock speed than the HD 6870, but the HD 6870 has 8 more Render Output Units than the GTX 660. As a result, the HD 6870 exhibits a 4.3 GPixel/s better Pixel Fill Rate than the GTX 660. However, both GPUs support DirectX 9 or above, and pixeling performance is only really relevant when comparing older cards.

The GTX 660 was released less than a year after the HD 6870, and so they are likely to have similar driver support for optimizing performance when running the latest games.

The GTX 660 has 1024 MB more video memory than the HD 6870, so is likely to be much better at displaying game textures at higher resolutions. This is supported by the fact that the GTX 660 also has superior memory performance overall.

The GTX 660 has 9.8 GB/sec greater memory bandwidth than the HD 6870, which means that the memory performance of the GTX 660 is marginally better than the HD 6870.

The Radeon HD 6870 PowerColor 1GB Edition has 1120 Shader Processing Units and the GeForce GTX 660 Direct CU II OC Edition has 960. However, the actual shader performance of the HD 6870 is 504 and the actual shader performance of the GTX 660 is 1042. The GTX 660 having 538 better shader performance and an altogether better performance when taking into account other relevant data means that the GTX 660 delivers a noticeably smoother and more efficient experience when processing graphical data than the HD 6870.

The GTX 660 transistor size technology is 12 nm (nanometers) smaller than the HD 6870. This means that the GTX 660 is expected to run slightly cooler and achieve higher clock frequencies than the HD 6870.

We would recommend a PSU with at least 500 Watts for the HD 6870 and a PSU with at least 450 Watts for the GTX 660. The HD 6870 has been recommended a PSU with 50 Watts more than the GTX 660. The difference is significant enough that the HD 6870 may have a slight adverse affect on your yearly electricity bills in comparison to the GTX 660.

Game FPS Benchmarks On Ultra

GPU Architecture

Core Speed900 MHzvs1020 MHz
Boost Clock-vs1085 MHz
ArchitectureTerascale 2 Barts XTKepler GK106-400-A1
OC Potential Fair vs Fair
Driver Support Poor vs Good
Release Date01 Nov 2011vs01 Sep 2012
GPU LinkGD LinkGD Link

Resolution Performance

1366x768 - green tick vs green tick -
vs green tick
vs green tick
vs green tick
3840x2160 - vs green tick

GPU Memory

Memory1024 MBvs2048 MB
Memory Speed1050 MHzvs1502 MHz
Memory Bus256 Bitvs192 Bit
Memory TypeGDDR5vsGDDR5
Memory Bandwidth134.4GB/secvs144.2GB/sec
L2 Cache 512 KB green tick vs 384 KB
Delta Color Compression no vs no
Memory Performance 0% green tick vs green tick 0%

GPU Display

Shader Processing Units1120vs960
Actual Shader Performance24%vs50%
Texture Mapping Units56vs80
Texture Rate50.4 GTexel/svs81.6 GTexel/s
Render Output Units32vs24
Pixel Rate28.8 GPixel/svs24.5 GPixel/s

GPU Outputs

Max Digital Resolution (WxH)2560x1600vs4096x2160
VGA Connections0vs0
DVI Connections2vs2
HDMI Connections1vs1
DisplayPort Connections-vs-

GPU Power Requirements

Max Power--
Recommended PSU500 Wattsvs450 Watts & 24 Amps

GPU Features

Shader Model5.0vs5.0
Open GL4.3vs4.5
Open CL-vs-
Notebook GPUnono

GPU Supporting Hardware

Recommended ProcessorIntel Core i5-760 2.8GHzvsIntel Core i5-3470 3.2GHz
Recommended RAM8 GBvs8 GB
Maximum Recommended Gaming Resolution1920x1080vs1920x1080

Gaming Performance Value

Crysis 3vs
Performance Value

GPU Mini Review

Mini ReviewRadeon HD 6870 PowerColor 1GB Edition is a special edition of the high-end Radeon HD 6870. See its page for more information about it.
It has no new features and so it can be addressed as a renamed Radeon HD 6870. Therefore its performance is exactly like the standard's.
GeForce GTX 660 Direct CU II OC Edition is a special edition of GeForce GTX 660.
The new features include DirectCU II cooling solution which, according to Asus, is 20% more effective than the standard/reference cooler.
In terms of overclocking, the base-clock was increased from 980MHz to 1020MHz and the boost clock can now reach 1085MHz, instead of 1033MHz. The memory clock was left untouched.
Benchmarks indicate a 4% performance boost when compared to the reference card.
Recommended CPU
Possible GPU Upgrades
GPU Variants