Advice on 2x R9 280x setup for Litecoin Dogecoins

[yannis7777]

Hello everyone i would be grateful if a kind soul would reply this:
I have got one Sapphire R9 280x Vapor X and thinking of placing another one on the board for mining at double hashrates (currently getting 650kh/s) on litecoins, dogecoins. My questions are these and replies would be appreciated since i am a noob on this:
1. Would i be able to run them independently without them crossfiring on the board (Gigabyte 970A-UD3P)? Or alternatively do i have to manually undo the crossfire if they automatically crossfire to one another? In essence i need to get twice the hashrates but i do not know if there will be any problems with crossfiring on the board (do they auto crossfire can i avoid them from doing so etc).
2. If i get a R9 of another brand (still a 280x) would i be fine running them on the same board?
Many thanks in advance.

[patricktim]

may I know what are you mining?

[yannis7777]

i am mining dogecoins sorry for not mentioning this (i edited the topic title too)

[bl8cz]

Hi,

it's not a problem to use 5 or 6 of these cards in one mobo. Crossfire is not necessary. I run 3 different kinds of 280x i a single rig, but it's quite hard to set all to do the max hashrate. You say you do 650kH/s. On 280x you should do at least 740kH/s. 650 is just waste of electricity;)

[skleven]

Hi,

it's not a problem to use 5 or 6 of these cards in one mobo. Crossfire is not necessary. I run 3 different kinds of 280x i a single rig, but it's quite hard to set all to do the max hashrate. You say you do 650kH/s. On 280x you should do at least 740kH/s. 650 is just waste of electricity;)

280X Vapor-X can do over 800kh/s with the right settings. 

[Sommeck]

Hi,

it's not a problem to use 5 or 6 of these cards in one mobo. Crossfire is not necessary. I run 3 different kinds of 280x i a single rig, but it's quite hard to set all to do the max hashrate. You say you do 650kH/s. On 280x you should do at least 740kH/s. 650 is just waste of electricity;)

280X Vapor-X can do over 800kh/s with the right settings. 

Ah ok...over 800kh/s  can you say me how do you get so high hash rates?

I have also Vapor x r9 280x and a single card runs at 730kh/s
In my rigs with 5 vapor x r9 280x i only get 690kh/s

[Victoo]

Hi,

it's not a problem to use 5 or 6 of these cards in one mobo. Crossfire is not necessary. I run 3 different kinds of 280x i a single rig, but it's quite hard to set all to do the max hashrate. You say you do 650kH/s. On 280x you should do at least 740kH/s. 650 is just waste of electricity;)

280X Vapor-X can do over 800kh/s with the right settings. 

Ah ok...over 800kh/s  can you say me how do you get so high hash rates?

I have also Vapor x r9 280x and a single card runs at 730kh/s
In my rigs with 5 vapor x r9 280x i only get 690kh/s

Yeah I would like to see those settings too. I heard no one getting over 700kh/s with 280x yet.

[skleven]

Hi,

it's not a problem to use 5 or 6 of these cards in one mobo. Crossfire is not necessary. I run 3 different kinds of 280x i a single rig, but it's quite hard to set all to do the max hashrate. You say you do 650kH/s. On 280x you should do at least 740kH/s. 650 is just waste of electricity;)

280X Vapor-X can do over 800kh/s with the right settings. 

Ah ok...over 800kh/s  can you say me how do you get so high hash rates?

I have also Vapor x r9 280x and a single card runs at 730kh/s
In my rigs with 5 vapor x r9 280x i only get 690kh/s

Yeah I would like to see those settings too. I heard no one getting over 700kh/s with 280x yet.

I`m currently only running Toxic, but a friend of mine have 3x vapor-x. I belive his settings are 1150/1800/powertune 20/cgminer 3.4.2 and the latest
AMD driver. My toxic runs at 1130/1850= 810kh/s avg. Usually, when going over 1500mem, hashrate goes down. But up again around 1800. Ofcourse you need to finetune around this area, because no gpu`s are identical it seems.