Topic: What hash rate can I expect from 3 x 7850s? (Read 16231 times)
I'm able to get around 360 kHash per card with moderate OC in Scrypt mining with my 7850s, could probably get that up more with some better cooling.
FWIW my ASUS HD7850-DC2-2GD5-V2 is giving 331Mh/s. This is with 1100 engine, 950 memory, intensity 7, diablo kernel under CGminer 3.1. Temp is running 60C.
For the record, running stable at 341.9Mh/s. Still experimenting.
Bitcoin - I can get about 330MH/s off the 7850 vs 430-450MH/s on the 7970's
LTC - I can get close to 400KH/s on the 7850
The 7870's have some kind of issue I haven't resolved yet but so far they are mostly BTC. I've seen 550-750KH/s (depends on intensity) off the pair but the actual work completed (U: score) is closer to 350KH/s.
LTC - I can get close to 400KH/s on the 7850
The 7870's have some kind of issue I haven't resolved yet but so far they are mostly BTC. I've seen 550-750KH/s (depends on intensity) off the pair but the actual work completed (U: score) is closer to 350KH/s.
Running 2 rigs (soon to be 4 rigs) with 4 7850s each.
Each GPU gets 320 M/hash at 1095 OC. For a 24/7 operation I cant get them to go higher. Also its open air non cased, in front of a window AC unit.....
7850's are the best bang for buck, unless you can get 7950's on sale.
Each GPU gets 320 M/hash at 1095 OC. For a 24/7 operation I cant get them to go higher. Also its open air non cased, in front of a window AC unit.....
7850's are the best bang for buck, unless you can get 7950's on sale.
what's the PSU your are using to power up these 4 together.
BTW which 7850 still have undervolt feature available or are they all locked now?
With 1100 clock/1250 mem 1.46 vcore and --intensity 14 --lookup-gap 2 --thread-concurrency 8192 --worksize 256 -g 1 I am able to pull in around 370 KHash/s mining Litecoin without any stability issues or cgminer errors, averaging 955 KHash/s with 3 cards.
Ive been mining litecoin so im not too sure how the numbers compare.
I have 3x 7850 @ 1100 Core/1200 Memory, average around 380KH/s each
./cgminer --lookup-gap 2 -I 20 --thread-concurrency 8192 -w 256
https://i.imgur.com/oD2ovzF.png
I have 3x 7850 @ 1100 Core/1200 Memory, average around 380KH/s each
./cgminer --lookup-gap 2 -I 20 --thread-concurrency 8192 -w 256
https://i.imgur.com/oD2ovzF.png
Thanks for the specs, I in cgminer Im rolling around 320 Khash/s each with similar settings, I will try this config and see if it improves.
Ive been mining litecoin so im not too sure how the numbers compare.
I have 3x 7850 @ 1100 Core/1200 Memory, average around 380KH/s each
./cgminer --lookup-gap 2 -I 20 --thread-concurrency 8192 -w 256
https://i.imgur.com/oD2ovzF.png
I have 3x 7850 @ 1100 Core/1200 Memory, average around 380KH/s each
./cgminer --lookup-gap 2 -I 20 --thread-concurrency 8192 -w 256
https://i.imgur.com/oD2ovzF.png
Can you guys post you OC settings like core and men clocks, voltage, fan speeds,etc? I've hit a limit and my middle card is over 100C!
Why do you need a case? You're going to trap a lot of hot air inside.
I cant get my cards to stay stable at 1100 core clock, so I keep them at 1050. Sucks because they dont go over 70C, tend to stay around 60C.
Ok, it was pretty easy to ramp these Sapphire's up to around 320 Mhash/s from 250 stock, with a core clock of 1106 and a slight voltage bump with the TriXX utility, no problems so far. I can see the middle card getting fairly warm, Ill need to throw some more fans around them to go further probably. Grand total 960 Mhash/s
Well this is handy info, I am typing this post from my new mining rig 
3x 7850's also.
These are Sapphire HD 7850 OC's, they have an open air style dual-fan heatsink, we'll see how they handle the heat after some OCing. These things can be had for about $165 all over the place, seemed to be the best deal for the power they can deliver.
3x 7850's also.These are Sapphire HD 7850 OC's, they have an open air style dual-fan heatsink, we'll see how they handle the heat after some OCing. These things can be had for about $165 all over the place, seemed to be the best deal for the power they can deliver.
Your clocks are bad and you should feel bad. Experiment. My perfect ratio is 912core and 1250 mem, (this is a 5770 and a 6770) I get 210kh/s. If I put it to 913core i drop to 160kh/s and 1250+ mem drops aswell. Also this is about scrypt. There is no point doing bitcoin with only those type of GPU's. Do litecoin.
To cool your gpu's get 2 fans, pushing air inbetween the gpus.
To cool your gpu's get 2 fans, pushing air inbetween the gpus.
FYI I've got only two running right now due to high temps with the middle card. Need to see how this is going to work in a closed case with three cards. May have to seriously change the plan.
With 2 x 7850, both OC to 1200MHz Core, 1300MHz Memory @ 1.18V, fan speed 85%, about 330Mh/s with cgminer intensity 9, and about 73-75C each under load for a day.
I'm petty happy with this, but certainly hoped for more! I could play more but am OK for now until I get a few BTC. Any suggestions? Would changing the intensity help at all?
With 2 x 7850, both OC to 1200MHz Core, 1300MHz Memory @ 1.18V, fan speed 85%, about 330Mh/s with cgminer intensity 9, and about 73-75C each under load for a day.
I'm petty happy with this, but certainly hoped for more! I could play more but am OK for now until I get a few BTC. Any suggestions? Would changing the intensity help at all?
Spot on! 3x GPUs is about 460 Watts! 
I was getting about 750MH/s with 3x GPUs, but the middle one was running too hot. Now with 2xGPUs I get 525MH/s, so about 250MH/s each. This is stock. I will start OC tonight. I'm hoping for at least 300MH/s each OC. Next step is to get risers so I can get some more airflow between the cards. Suggestions to support the cards without PCI brackets?
I was getting about 750MH/s with 3x GPUs, but the middle one was running too hot. Now with 2xGPUs I get 525MH/s, so about 250MH/s each. This is stock. I will start OC tonight. I'm hoping for at least 300MH/s each OC. Next step is to get risers so I can get some more airflow between the cards. Suggestions to support the cards without PCI brackets?
Oh I forgot the best part. Im pulling 580 watts out of the wall with those 4 gpus. I bought a watt meter to keep tabs on my power. Doing math X3 would prob consume 450 watts.
Running 2 rigs (soon to be 4 rigs) with 4 7850s each.
Each GPU gets 320 M/hash at 1095 OC. For a 24/7 operation I cant get them to go higher. Also its open air non cased, in front of a window AC unit.....
7850's are the best bang for buck, unless you can get 7950's on sale.
Each GPU gets 320 M/hash at 1095 OC. For a 24/7 operation I cant get them to go higher. Also its open air non cased, in front of a window AC unit.....
7850's are the best bang for buck, unless you can get 7950's on sale.
On that mining hardware page what you find is a lot of extremes. Like the person only getting 525MH/s with a 7950. Or somebody mining with a 7970 outside in a snowy area so that they are able to overvolt the card to crazy voltages and fan speeds.
Any time you run multiple cards the weakest card will bring the rest down even if you use independent settings. The heat from each card increases the power usage by requiring more fan speed and voltage to remain stable.
Expect 310 from each card, and anything above that is good luck and some skill with tweaking.
Any time you run multiple cards the weakest card will bring the rest down even if you use independent settings. The heat from each card increases the power usage by requiring more fan speed and voltage to remain stable.
Expect 310 from each card, and anything above that is good luck and some skill with tweaking.
You wont see 400MH/s unless you run 7870s
I think sometimes people quote unstable MH/s on that page that only last a few minutes.
Anything over 330MH/s will crash a lot.
I think sometimes people quote unstable MH/s on that page that only last a few minutes.
Anything over 330MH/s will crash a lot.
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