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little question about crossfire and my 6870

post #1 of 5
Thread Starter 
Hi all I have the opportunity to buy an asus 6870 1 gb card for $75 I already own a gigabyte 6870 1 gb.

1st at this price do you think it would be a decent idea to grab it and cossfire
When crossfire since each card has 1 gb to I now how 2 gb of memory or does the same information get loaded into each card's memory?
     
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post #2 of 5
To answer your questions a bit backwards - yes the information gets loaded into each GPU memory so its not additive - for $75 you should definitely jump on that 6870 for CF, you'll see a nice performance boost (between 70 - 100% generally )
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post #3 of 5
Thread Starter 
o cool thanks !
     
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post #4 of 5
OP think about selling your HD 6870 1GB card for 80 - 90 bucks. spend another 100 bucks and get a HD 7870 2GB. overclock it to 1.15 - 1.2 ghz and you are going to run faster than HD 6870 CF. HD 6870 has very less OC headroom, probably 50 - 75 mhz and its perf scaling is poor. HD 7870 OC scales very well and gains 15 - 20% perf at 1.2 ghz. HD 7870 has 2 GB which allows you to run higher settings without running into VRAM bottlenecks.

http://www.hardocp.com/article/2013/05/15/asus_radeon_hd_7870_directcu_ii_v2_review/1

HD 7870 OC will provide more consistent and smoother perf than HD 6870 CF. no CF issues with single HD 7870 compared to HD 6870 CF. HD 6000 series architecture has poor tesselation and compute performance compared to GCN based HD 7000 series. even in the best cases where scaling is 1.8x , a HD 6870 CF will just match HD 7870 OC. if scaling is poor the HD 6870 CF falls behind and in games like COH 2 where there is no SLI / CF support the HD 7870 OC will destroy HD 6870 CF.

http://www.techspot.com/review/689-company-of-heroes-2-performance/page2.html

1920 x 1200 Medium quality
HD 7870 - 40
HD 6870 - 22

http://www.techspot.com/review/670-metro-last-light-performance/page3.html

1920 x 1200 High quality AF x16
HD 7870 - 39
HD 6870 - 22

http://www.techspot.com/review/645-tomb-raider-performance/page3.html

1920 x 1200 Ultra quality FXAA 16xAF

HD 7870 - 52
HD 6870 - 31

http://www.newegg.com/Product/Product.aspx?Item=N82E16814202025
http://www.amazon.com/Sapphire-DL-DVI-I-SL-DVI-D-PCI-Express-100354OC-2L/dp/B00A2J4ROE
Edited by raghu78 - 7/20/13 at 10:50pm
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post #5 of 5
Thread Starter 
Warning: Spoiler! (Click to show)
Quote:
Originally Posted by raghu78 View Post

OP think about selling your HD 6870 1GB card for 80 - 90 bucks. spend another 100 bucks and get a HD 7870 2GB. overclock it to 1.15 - 1.2 ghz and you are going to run faster than HD 6870 CF. HD 6870 has very less OC headroom, probably 50 - 75 mhz and its perf scaling is poor. HD 7870 OC scales very well and gains 15 - 20% perf at 1.2 ghz. HD 7870 has 2 GB which allows you to run higher settings without running into VRAM bottlenecks.

http://www.hardocp.com/article/2013/05/15/asus_radeon_hd_7870_directcu_ii_v2_review/1

HD 7870 OC will provide more consistent and smoother perf than HD 6870 CF. no CF issues with single HD 7870 compared to HD 6870 CF. HD 6000 series architecture has poor tesselation and compute performance compared to GCN based HD 7000 series. even in the best cases where scaling is 1.8x , a HD 6870 CF will just match HD 7870 OC. if scaling is poor the HD 6870 CF falls behind and in games like COH 2 where there is no SLI / CF support the HD 7870 OC will destroy HD 6870 CF.

http://www.techspot.com/review/689-company-of-heroes-2-performance/page2.html

1920 x 1200 Medium quality
HD 7870 - 40
HD 6870 - 22

http://www.techspot.com/review/670-metro-last-light-performance/page3.html

1920 x 1200 High quality AF x16
HD 7870 - 39
HD 6870 - 22

http://www.techspot.com/review/645-tomb-raider-performance/page3.html

1920 x 1200 Ultra quality FXAA 16xAF

HD 7870 - 52
HD 6870 - 31

http://www.newegg.com/Product/Product.aspx?Item=N82E16814202025
http://www.amazon.com/Sapphire-DL-DVI-I-SL-DVI-D-PCI-Express-100354OC-2L/dp/B00A2J4ROE

no thank you
     
CPUMotherboardGraphicsRAM
AMD Phenom II X4 840@3.8Ghz Biostar A870U3 Power Cooler 6970 4x4Gb G.skill ribjaw 
Hard DriveHard DriveOptical DriveCooling
WDCaviar Black 500GB Crucial M4 64GB Sony Optiarc CD/DVD Burner 2x200mm fans 
CoolingCoolingOSMonitor
Antec kuhler H20 620  2x120mm fans push/pull Win7 Pro 64bit LG 24" 1080p + Dell 23" 1080p 
KeyboardPowerCaseMouse
GIGABYTE GK-K6800  COOLER MASTER GX 650W COOLER MASTER HAF 922 Tt esports Saphira 
Mouse PadAudio
Tt esports Phyrrsus compact Sennheiser HD 201 
  hide details  
Reply
     
CPUMotherboardGraphicsRAM
AMD Phenom II X4 840@3.8Ghz Biostar A870U3 Power Cooler 6970 4x4Gb G.skill ribjaw 
Hard DriveHard DriveOptical DriveCooling
WDCaviar Black 500GB Crucial M4 64GB Sony Optiarc CD/DVD Burner 2x200mm fans 
CoolingCoolingOSMonitor
Antec kuhler H20 620  2x120mm fans push/pull Win7 Pro 64bit LG 24" 1080p + Dell 23" 1080p 
KeyboardPowerCaseMouse
GIGABYTE GK-K6800  COOLER MASTER GX 650W COOLER MASTER HAF 922 Tt esports Saphira 
Mouse PadAudio
Tt esports Phyrrsus compact Sennheiser HD 201 
  hide details  
Reply
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