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running a 3850 256 mb and 3870 512mb in crossfire

trt740

trt740

Joined
May 12, 2006
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11,119 (1.70/day)
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System Name Apple Bite
Processor Intel I5
Motherboard Apple
Memory 40gb of DDR 4 2700
Video Card(s) ATI Radeon 500
Storage Fusion Drive 1 TB
Display(s) 27 Inch IMac late 2017
If you used these two cards which ram would be used the 512mb or the 256 or would both be used. I know in SLI the card with the least ram is used and if one card has a faster clock speed the lowest cpu speed is used on both cards. I'm not sure about crossfire someone please explain.
 
Random Murderer

Random Murderer

The Anti-Midas
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System Name TOO MUCH RADIATOR! | The TV Box a.k.a. The Shoebox
Processor Core i7 4930K @ 4.5GHz | Core i5 6600K @ 4.5GHz
Motherboard Asus X79 Rampage IV Extreme | Asus Z170i Pro Gaming
Cooling Custom water on CPU and GPU, dual 360mm radiators | Corsair H80i
Memory 4x 8GB G.Skill TridentX DDR3-1600 | 2x 4GB G.Skill RipJaws 4 DDR4-3000
Video Card(s) Sapphire AMD R9 295x2 | PowerColor AMD HD7970
Storage Samsung SSD 830 256GB, various others | 2x 1TB Seagate Barracudas in RAID1
Display(s) Dell U2713HM 2560x1440 IPS | Panasonic TC-L32E5 1080p IPS TV
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you would use all the memory from the 3850 and the matching size on the 3870, so 512 would be used, 256 on each.
 
ompak5

ompak5

Joined
Jul 21, 2005
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according to white paper from AMD, the card with higher memory will adjust into least memory to much the lower card speed and memory! actually the CCC will detect it then restart the system to adjust the memory speed and memory!!! On my system 2600xt in master and 2600 pro in slave the crossfire cannot enable although the GPU-Z detected 2 cards in crossfire but it was disable on software!!! if i wer you go buy same core GPU although the memory is not yhe same..
 
Random Murderer

Random Murderer

The Anti-Midas
Joined
Dec 6, 2006
Messages
6,974 (1.10/day)
Location
Florida, A.K.A. the Sweatbox
System Specs
System Name TOO MUCH RADIATOR! | The TV Box a.k.a. The Shoebox
Processor Core i7 4930K @ 4.5GHz | Core i5 6600K @ 4.5GHz
Motherboard Asus X79 Rampage IV Extreme | Asus Z170i Pro Gaming
Cooling Custom water on CPU and GPU, dual 360mm radiators | Corsair H80i
Memory 4x 8GB G.Skill TridentX DDR3-1600 | 2x 4GB G.Skill RipJaws 4 DDR4-3000
Video Card(s) Sapphire AMD R9 295x2 | PowerColor AMD HD7970
Storage Samsung SSD 830 256GB, various others | 2x 1TB Seagate Barracudas in RAID1
Display(s) Dell U2713HM 2560x1440 IPS | Panasonic TC-L32E5 1080p IPS TV
Case Thermaltake Suppressor F51 (stripped down to hold two radiators) | Cooler Master Elite 130
Audio Device(s) RM-DAC -> Xiang Sheng 708b -> Sennheiser HD650 | HDMI sound device on 7970
Power Supply LEPA G1600-MA 1600W | Corsair CX750M 750W
Software Win 10 64
Benchmark Scores over 9000 BungholioMarks, "Bitchin' Fast"
ompak5 said:
according to white paper from AMD, the card with higher memory will adjust into least memory to much the lower card speed and memory! actually the CCC will detect it then restart the system to adjust the memory speed and memory!!! On my system 2600xt in master and 2600 pro in slave the crossfire cannot enable although the GPU-Z detected 2 cards in crossfire but it was disable on software!!! if i wer you go buy same core GPU although the memory is not yhe same..
Click to expand...

well the 3850 and 3870 ARE crossfire compatible, it's the new technology "crossfire x"
 
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