December 7th, 2013 
CryptoBadger Now that the excellent Radeon 7950 video cards have essentially become unobtainable, I’m getting a lot of questions from people about how to get the most out of the new Radeon R9 280X in terms of mining. I managed to get my hands on a few Sapphire 280X cards this past week, and have done a little bit of experimenting.
I’ll get around to updating my guide for the 280X at some point in the next couple weeks, but if you’re looking for a good starting point as far as cgminer and undervolting settings go, read on.
Undervolting and Power Consumption
First, the 280X is essentially a re-branded 7970, which means they can be undervolted using VBE7 and the method I previously outlined for the 7950. My Sapphire cards run completely stable at 1137 mV, so if you’re following my undervolting guide, simply use 1137 in place of the 1081 that I recommended for the 7950. I’ll test lower voltages at some point soon, but the 7970/280X doesn’t have a stellar reputation as far as undervolting goes, so I wouldn’t expect too much more.
Running at 1137 mV, you can expect a 3 GPU rig to use between 850-900 watts at the wall, assuming you’re using the rest of the hardware that I recommend in my 7950 guide. You will, of course, need to upgrade the power supply to something a bit larger to accommodate the 280X’s larger power draw—I recommend a 1000+ watt gold or platinum rated PSU. The best choice for those of you without access to very cheap electricity is probably something like this platinum-rated Seasonic PSU. This gold-rated Corsair is a bit less expensive and also a good choice. If you’re looking to run four GPUs, this eVGA PSU has enough PCIe connectors without dealing with splitters.
Cgminer Settings and Performance
These are early test results, but they should get most of you up and running with acceptable performance. My tests were done on a platform with all of the hardware outlined in my guide, the only exception being that the PSU was substituted for a larger 1000 watt unit, and of course the 7950 GPUs were replaced with 280X cards.
For my tests, I was running Xubuntu 12.04 with the latest beta AMD Catalyst drivers installed, AMD SDK 2.7, and cgminer 3.7.2. I’m also using a 280X-optimized scrypt kernal in cgminer. I’ll be looking at Xubuntu 13.x and other driver versions (and Windows, too!) in the coming weeks.
The best results I saw were with the following cgminer settings:
-I 13 -g 2 -w 256 --lookup-gap 2 --thread-concurrency 8192 --gpu-engine 1000 --gpu-memclock 1500 --temp-target 70 --auto-fan
This gets me roughly 710 Kh/sec per GPU, completely stable. Oddly enough, setting the core clock speed any higher than 1000 mhz results in lower cgminer performance.
I’ve read about some people getting speeds up to 750 Kh/sec with other brands and/or other configurations, but in my limited testing that was the best that I was able to achieve without compromising stability.
If you have another brand of 280X, you may want to try 1080 mhz or 1060 mhz for the core clock speed (--gpu-engine 1080), as many people report the best success in that range.
One interesting note is that the 280X seems to be pretty sensitive to heat, and will self-throttle its performance down whenever GPU temperatures get over 70C or so (at least, my Sapphires do). Setting cgminer’s auto-fan temp at 70C prevents this, although I run my rigs in a fairly cold room—some of you may need to point a box fan at your rigs to get the best performance out of your 280Xs.
I’ll be trying to get my hands on other brands of 280X cards, especially the ones by Gigabyte and MSI (although many are reporting good results with the Asus and PowerColor models, too)—although I’m sure most of you have noticed that they’re fairly difficult to come by right now.
If you’re currently running a 280X-based rig, please feel free to leave a comment below with your settings and results!
Posted in 
I am seeing many more 280x rigs out there due to the increase in cost of the 7950s and the lack thereof of said cards. I have just watched as they went from 250 to over 400 a card. Now, we are forced to go with 280x’s at a less than perfect watt rate. You can see how much I am earning on my daily record page over at my site. Click my name if interested. I have a 4400 kilohash rig rolling nicely over at multipool and the results might shock you.
Love your site Badger.
Hi Kishkumen!
I am building 2 rigs with 2 cards each, because the PSUs that I got are 750W, thus not enough for more than 2 cards. The point is to add more cards later if I figure out a way to connect 2x750W PSUs to work together on one board. It is cheaper that way, than buying a single expensive 1200W+ PSU.
I did some more tests with the bad card, but nothing happened. I tried with it alone in the rig – no post. I also tried one working card in the PCIe x16 slot and the bad card in PCIe x4 slot and the result was the system booting and crashing at the windows 8 welcome screen. Windows eventually loaded and I saw only one gpu recognized in Device Manager. BIOS was still showing 2 GPUs present on the PCIe slots, but at that point I decided to quit. I have already returned the faulty card to service and I am on the 1-month replacement queue now. Sapphire is really struggling to fulfil all orders at the moment. Hopefully more cards that I have ordered will come next week, so I will fill my gap.
As for the current working setups – I am not using crossfire, of course, that was just for testing. No dummy plugs either.
Drivers are 13.12 + SDK 2.9. Windows 8.1. The cgminer settings I am using are:
setx GPU_MAX_ALLOC_PERCENT 100
setx GPU_USE_SYNC_OBJECTS 1
-I 13 -w 256 -g 2 –thread-concurrency 8192 –gpu-engine=1080 –gpu-memclock=1500 –gpu-powertune 20 –lookup-gap 2
What I found out so far after some tweaking, is that playing with those cgminer settings doesn’t give me a good enough increase. The rig with 2 cards had no problems reaching 700Kh/s and above from scratch, but I struggled a lot with the single-card rig in order to make it go above 550Kh/s. Using Sapphire’s TRIXX utility was the key. I experimented with the core/memory/voltage settings there and it turned out that going up to 1095 for core, or 1600 for memory, or decreasing the voltage too much – all of these only worsen the hashrate. I found 1080c, 1500m, 1.118V to be the best settings so far, producing around 730Kh/s for the single-card rig. Note that there is a -50 decrease in the memory from default. 🙂 Lower voltage gives me lower hashrate and at about 1.08V windows froze. The card runs with the above settings at around 65C degrees.
What I found strange is that 2 of these 3 cards run by default at 1.200V and one of them is reporting 1.131V default in TRIXX. I don’t know how that happens. Could it be a card-specific issue or should I take it as normal?
The other rig with the 2 cards is mining safely with 1480Kh/s total for more than a day already. I do have a small problem with one of the cards absorbing heated air from the other one, so the temps are 66C and 79-82C respectively. When the hotter card reaches 82C the fans go above 3000rpm for a while to take it down to 79C. The cooler card stays at around 1500-1600rpm and is fairly quiet. I will eventually get some riser cables in order to separate the cards for better cooling. But since it’s winter now – I can easily find a place for the rigs on the balcony where it is -2C now. 🙂
Thanks a lot for your comments! I will keep posting if I find out something interesting about the settings.
Trixx topic: https://bitcointalk.org/index.php?topic=40701.0
I have a rig with both a 7950 and r9 280x. the r9 280 occupys gpu 0, so i should use the setting in cg miner -g 2. however, when I try to optimize both cards, the setting -g 2,1 results in cgminer quitting, and just leaving it in -g 2 results in a full on crash, does anyone know how to get around this ?
Hi Rad,
To be honest, I find your reasoning behind 2 rigs kinda weird. If your point is to add cards later, your 750w PSU still won’t be enough. Aside of that you need to buy a extra Mainboard, CPU, Memory and possibly harddrive just to run the second rig. In my eyes a 1200w PSU is cheaper then the Combi: 750w, Mainboard, CPU, Memory and Harddrive… I’d reconsider your reasoning, but its your party 😛
1080c / 1500m / 1131v is about the best that you’ll get (+/- 750 Kh/s) with the card indeed, and that’s what I’m running at too.
ABOUT SAPPHIRE TRIXX BEING A BITCH:
The reason behind 1 card showing as 1.131V and 2 as 1.200V is because they are actually running at 1.200V. Trixx wont apply the settings unless you manually set the 2 cards using the dropdown menu at the top. The same goes for FAN settings in Trixx. If you reboot your Rig, and autostart everthing including Trixx only the first card settings will be loaded, not the second or third.
So every time you reboot your system you need to manually set Trixx for cards 2 and 3. Remember this! (Unless someone knows a fix?)
Oh and buy a Kill-A-Watt / Energy Meter. It’s a guarantee that your undervolting works because of power consumption dropping.
Last but not least: I would’nt put sensitive electronis like a PC outside without proper housing. I dont think it lasts very long, you know with moisture, condensation, wind and the occasional random animal that comes by and shits on it.
Anyway,
Maybe i’ll get a update, good luck.
Hi Kishkumen,
The reasoning behind the 2 rigs also has something to do with the fact that one is mine and one is my brother’s, although they will most likely stay at the same place. Other than that, quality PSUs are out of stock in all suppliers where I live, just like any cards above R9 270X. It’s another 1-month queue of waiting if I want to order 1200W+. The balcony is glass-insulated, by the way, not open-air, so no animals and rain there. 🙂
About the voltage – I know they are supposed to run at 1.2V, but strangely one card defaults to 1.131. That’s without any human interference – just factory default, shown in TRIXX after reboot.
I am running them at 1.1V with TRIXX. That’s the lowest stable voltage I could get to. At 1.08V they seemed to be ok, until I found one of the cards not mining yesterday morning. I had to revive it by upping the voltage to 1.1V. No malfunctions since then.
Here’s a general thing that I just don’t understand. I have two different kinds of Sapphire cards, the Dual-X and the Tri-X. The Tri-X seems to get about 815KH with a specific set of settings. The Dual-X gets 600KH with the exact same settings.
There’s no temperature issues (the Dual-X is actually running cooler). The voltages are a bit different… but everything else is identical.
The reason I don’t get it is: I thought all 280X cards had the same chips on them, and you would think that if you could get it to run at the same gpuengine/gpumemclock with good stability (temperature or otherwise) that they would hash at the same rate. Can anyone educate me?
Thanks.
Rakujin,
You have a R9 280 that does 815 Kh/s ? Thats very high. Are you sure your looking at your kh/s and not WU? As far as I know only R9 290 and 7990 cards go past 800 kh/s.
What are the settings for the 815 Kh/s card ?
Apologies for the Typo on: Hakujin 😛
Yeah I’m sure I’m not looking at WU. It fluctuates between 800 and 815.
The card is a stock Sapphire Tri-x (not Toxic), I didn’t fiddle with any settings, just used one from the litecoin wiki. I think 1160 core clock, 1800 memclock, tc 8192, g 2, and w 256.
So with those exact same settings though the Dual-X does really poorly. I just don’t understand why that is.
Hi guys,
Did anyone tried Hakujin’s setting on the Tri-X ?
I actually runing a rig with 3 290x and I planning to make an other rig with 6*280X but I’m not sure wich one I should buy.
If a Trix-X can get 800Kh/s it’s pretty damn good. With my 290x I have 888Kh/s for twice the price !
Thanks for your advice on wich 280x I should buy.
I have two Tri-X and they both can do 815 with those settings under Linux. The only issue is I don’t know how much power they are drawing, they won’t run at that speed very stably unless they are getting 1.256v (or at least I had no luck).
So I’m not sure how easy it is to load 6 onto a rig, you might need two electrical circuits if you’re running 15A breakers.
I’ve tried Hakujin’s settings on a R9 280X Sapphire Toxic (it includes the Tri-X cooling) and i got about 807 Kh/s.
Previously, i had 1110 core clock, 1800 memclock, tc 8192, g 2, and w 256 and the Toxics ran at 772 stable.
I’m surprised R9 290X get only 888.
And Hakujin thanks a lot for sharing your settings!
Hakujin, I’m running Sapphire 7950’s. Have been all over the settings and found that the best settings for a 7950 (provided you can keep it in a cool enough environment) are eng 1100 mem 1500 I 20 powertune 20. Powertune is the biggest cause of high temp, and I have to adjust it down during warmer days to keep cgminer from shutting down.
At these settings my 3 gpu rigs show each gpu hashing up to 660 at the top of the cycle.
Where can I find Hakujin’s settings please ?
I’m near to get 3x Tri-X R9 280x cards (not the toxic).
Is it a good choice ? Is it better I get the Toxic ones ?
Thanks for help.
Hi,
I would go with one of these cards:
https://litecointalk.org/index.php?topic=12369.msg116032#msg116032
The guy in this thread really knows what he is talking about. And if you search for my answers in this thread, you can see that on my sapphire cards they used cheap vram controllers, which is bad if you want to overclock/undervolt.
I’m done with sapphire, next batch of cards are probably asus – but thats just my opinion.
Where are your settings for R9 280x Tri-X to get 815kh/sc please ?
Can you make a picture speed proof ?
Thanks a lot.
I NEED A LITTLE HELP
GOT 3 CARD RIG SAPPHIRE DUAL X (R9 280X)
WHEN RUNNING KH’S 560 PER CARD
BUT WHEN I RUN ONE CARD AT A TIME 745 KH’S
HOW DO I FIX SO THREE CARDS RUN ABOVE 700 AT ONCE
Add more ram.. ? 4 gb minimum for 3 cards… but go ahead and try with 8gb !
I installed a rig with 3 280x cards, I am lacking the 68-Ohm resistors at the moment. On Linux Xubuntu, from USB stick. All other settings and hardware are the same as in the Linux guide.
I am still tweaking settings, of coure… but largely the rig has been running stable for 5-6 days now without the 68-Ohm resistors or other dummy plugs.
I did not notice any decline in card performance due to eventual “idling” by the OS.
Can anyone confirm this?
I can say that without dummy plugs my rig(s) seem to run fine in Linux. I’d say in general rebooting them every week or two seems beneficial anyways, on occasion I’ve noticed a drop in hash rates after the rig has been “up” for too long.
Dummy plugs aren’t necessary with the up to date components now being used.
there are specific options in Xubuntu desktop to turn monitors off or not, that’s why it probably works for you without the dummy plugs (aside from the hardware per se not shutting down automatically?)
Running 9x HIS R9 280x. used 3 per motherboard with 1000w Cougar power supplies. Running extremely stable at 710 kh/s. used 1000 core clock and just left memclock setting blank to use default. The rest of the config mentioned in this article is right on. Temps stay between 72-77C without addition of extra cooling. Average temperature room on a large shelving setup. If this helps anyone, I am using 6 cards (two 1000w power supplies) on a 15amp circuit in my house. Using some Ohm’s law awesomeness, each card is well under 333kw/h or my breakers would pop. This is useful when calculating your power usage and cost. Has been running stable for weeks, though like others have mentioned, I prefer to restart the rigs about once a week as they do tend to migrate down to 680 or 690 kh/s after days of operation. Slightly off topic but worth mentioning for newbies…dont use cheap surge protectors or power strips. Unless you like the smell of hot plastic. Even rated to 15amps…some cheap power strips dont do well with 1800watts rolling through them.
have you used a kill-a-watt on those rigs? that seems a little high for one line.
what amp is your outlet and breaker rated for, and how many amps does a kill-a-watt read>?
I just realized I put a “k” where it didn’t belong. honest mistake. typing too many khash/s and watts and such. (Edit) Each card uses far less that 333 WATTS/hour. or .3 kw/h as your electric company would measure it. so pretty cheap. I always assume the 9 cards I have on three 1000 watt power supplies are costing me the MAXIMUM possible. which they are obviously not. That would be 3000watts or .3 kw. and that is a high estimate to make sure I cover my electricity costs. That should clear things up….but to answer your other question. Each outlet in the house is a 120v 15amp outlet. Every kilowatt is 8.333 amps. (1000 watts divided by 120volts) So if I put 6 cards on each breaker….and every three cards is two 1000 watt power supplies….the maximum possible draw would be 2000 watts per breaker….that would be over 16 amps per breaker. But my breakers dont pop. So the three cards per power supply are using less than 1000 watts…less than the maximum possible. I recommend still using the 1000w power supply for every 3 cards however. you need to cover the cpu/cpu fan/motherboard power and account for power spikes. Shorting yourself will cause crashes.
worst case scenario….9 cards costs me $6/day in electricity. This seems to add up with two months of electric bills. First 3 days of the month of mining at current exchange rates…covers the electricity. lets hope that keeps up.
i would use one of these
http://www.newegg.com/Product/Product.aspx?Item=N82E16882715001
its not recommended to run a line, outlet, or breaker at more than 80% capacity on a regular basis. that has to be at least 15-16 amps with 2 rigs running on one line.
That’s not a bad idea at all. I was just giving a base line for new miners to start at. Don’t expect to put more than two 1000 watt power supplies on the same residential 15 amp circuit. And you’re lucky if that works. and don’t expect to get more than 3 R9 280x’s out of one 1000 watt power supply…you’ll be lucky if that works. Hoping to help in the purchasing process.
I Get 720 kh/sec using I 13 core clock : 1000 memory clock : 1500 thread concurrency : 22400
hi,
i have a sapphire r9 280x dual-x card. has anyone an idea what are good settings? i only get about 540 – 600 kHs per second.
greetzs
The settings in the article are accurate to get close to 700. Make sure you’re not missing one of them. I’ve found the most important is intensity at 13, gpu-threads at 2, shaders at 2048 (I dont even set thread concurrency and it works) and memclock at 1500. Then play with the core clock until you get what you want.
You can use –shaders 2048 but it’s not recommended. cgminer / sgminer tries to find the correct settings for you. For finetuning you should use thread concurrency.
You can find a detailed description here: https://github.com/veox/sgminer/blob/master/doc/MINING
I know, the docs are for sgminer but work for cgminer too. But I chose to use sgminer, since it’s actively developed.
thank you guys!
The Asus r9 280x is nice.
sgminer settings:
–worksize 256 –intensity 13 -g 2 –thread-concurrency 8192
O/C settings: 799 khs.
1150 Core Clock
1800 Memory Clock
1.2 mV
I can go past 800 if I up the juice a little. I haven’t tested if this is stable though.
1175 Core Clock
1825 Memory Clock
1.231 mV
Gives me 816 khs.
another question:
it seemed to look quite good for about two days.
but… now i have another trouble. the cards are mining fine, it looks everything nice, at aboud 700kHs per card. but when i look at the mining pool online, there are no coins being confirmed O.o sometimes after a restart, there are some littal amount of coins confirmed.
i did not change anything in the config. i have no idea whats wrong, because it worked very well the last two days.
What pool are you using?
Do you get many rejects?
I like to use cgWatcher (works with cgminer AND sgminer), to see a little bit more statistics. You can combine it with cgRemote (costs a little, but I really like it).
fapfapraph,
Look at your account transactions page on your pool site to see what it shows. Everyone is sometimes subject to “orphan” transactions, where everything doesn’t work like it is supposed to and you get nothing. This happens to blocks and then it transfers I assume to the work on such an orphan block. It may be possible you have had this happen. Otherwise, if you can’t determine why no coins are showing after two days, I definitely advise changing to another pool to test your results there. Some people have definitely been cheated by the operators of certain pools.
Good Luck!
Did you type this command?
sudo chmod +x mine_litecoins.sh
If you didn’t and changed your start up scrypt without typing this command you will have that problem. Found this out the hard way too.
Have you measered how many watts you draw? Would be interesting to know 😉
I Get 720 kh/sec using I 13 core clock : 1000 memory clock : 1500 thread concurrency : 22400
I’m running 3x 280x Toxic Sapphire cards…They do a stable 720 on each with setting:
-I13 -g 2 -w 256 –lookup-gap 2 –thread-concurrency 8192 –gpu-engine 1060 –gpu-memclock 1500 –temp-target 70 –auto-fan
Got those settings from to manual over here and after some googling. Toxic version isn’t mentioned often…could I get a bit more out of these?
–gpu-engine 1080 gives me 740 khash stable
also you can undervolt to 1,20 – makes no problems on my 2 toxics
This guide has helped me to build my first rig. Really awewome and thanks!
I got 2 Asus 280X and mining at 730khashes per card. (1050/1500)
I’m trying to undervolt my cards via the Asus GPU Tweak Utility to save some energy and it’s working for my main card (the one connected to my screen), but the 2nd one will not be undervolted via this tool. Checked with sensors tab in GPU-Z.
MSI afterburner also doens’t work at all. I’m wondering how people undervolt their GPU’s in Windows 7 without modifying the BIOS. (I don’t want to lose my warranty)
Thanks. Appreciate any help.
I’m not sure if it’s working with Asus cards, but I undervolted my cards with Trixx: https://www.sapphireselectclub.com/ssc/TriXX/
Great! Thanks for reminding. Didn’t see that option when I tried it last time. Now it’s saving me 70 watt per GPU. 520 Watt now iso 660.
Hi Ed, all,
I am also trying to undervolt an Asus R9 280x DirectCUII Top (new revision). It seems not to happen in GPU Tweak and cgminer using –gpu-vddc=xxx; or within cgminer – it just says “Driver accepted settings, but check yourself” – and it hasn’t changed from stock 1.200V.
Does it mean you did it with Sapphire Trixx? As the maecky above suggested?
Do you save the settings to a profile, or also do something else to Hardcode the new lower voltage?
How do you do it for multiple cards too?
If somebody else can give useful hints – be my guest!
Thank you so much in advance!
P.S. Try 1080/1500 gpu/mem clocks – it gives the BEST hashrate – 750KH/s per card w/o overclocking.
I have the ASUS DirectCU TOPII as well. They are voltage locked from a software stand point, but you can lower the voltage using the BIOS trick that CryptoBadger describes. It doesn’t have a back up BIOS, so use at your own risk, but mine have fared quite well with undervolting. I have the pair of them happily hashing away getting 750+ @ 1080/1500 @ 1.100 Vddc. I think it can go even lower if I wanted to, but it’s a bit of a hassle and they never hit above 73 C and all four of my cards combined pull less than 1200 at the wall, so I’m happy to let them be.
On a side note, I finally sprung for a fourth card and as per recommendations on this comment board, got the powered 16X to 1X riser cable for the 1X PCIe slot and it works like a charm! I’ve maxed out my space and power supply capacity, but it’s running stable and strong!
Thanks again everyone!
Hi Stan,
I used VCCD settings in the .bat file and put it on 1.064 and using the Trix software to put them on 1.064 as well. You need to do it for both cards in the software. When I checked the voltage in Z-GPU i’m seeing voltages around 1.000 for both card.
I need to set the Trix software at every startup. It will only hold the voltage for the first card. The second one I need to do it manually.
Hope this helps. No bios change is required.
People!
766khash stable mining DOGE with:
Asus R9 280x DirectCU II TOP
I cant get better than this :/
[P]ool management [G]PU management [S]ettings [D]isplay options [Q]uit
GPU 0: 68.0C 2881RPM | 765.0K/766.7Kh/s | A:438 R:6 HW:0 U: 0.80/m I:13
GPU 1: 61.0C 2910RPM | 767.0K/766.2Kh/s | A:417 R:4 HW:0 U: 0.76/m I:13
GPU 2: 62.0C 2803RPM | 769.0K/766.6Kh/s | A:449 R:1 HW:0 U: 0.82/m I:13
SETS:
!!!! ./cgminer –scrypt -I 13 -g 2 -w 256 –lookup-gap 0 –thread-concurrency 8191 –gpu-engine 1110 –gpu-memclock 1500 –gpu-fan 100 -o !!!!!
Try please and if it work donate DOGE 🙂
DBn72dtXMnnspNcQc4SfD7Nrjgycj7Ubcx
Hi all,
I am trying to get a mining rig set up and am coming across some problems. Sorry if these questions have been asked before but here goes.
I have:
6 x PowerColour R9 280x 3gb GPU
ASrock z87 Killer motherboard
1000w Bronze 80plus cougar PSU
Win 7, Cgminer
8gb ram
My current set up supports 2 cards and I get about 740 kh/s per card. These two cards are on the board in the 16x Pci-e slots. When I add in another card on a powered PCI-e riser to a 1x slot (shorted), the machine recognises the card however it will not mine in cgminer and I get a sick/dead status.
I have tried different cards and different 1x slots (yet to try a different riser though).
I’ve been doing a lot of reading and I wonder if the card won’t work because the PSU is underpowered?
I have read that people are able to get 6 cards running off this mother board but I cannot even get 3 so far.
Also, after reading I am worried that even if I get another 1000w psu to power the other 3 cards that this will be too much energy draw coming from one power point.
I am quite confused so any help would be appreciated.
Are the riser cables powered? The mobo is not designed to deliver the necessary wattage through the 1X slot to sufficiently power these bigger GPU’s. I use the unpowered 1X risers on my 16X slots and they work fine, but I had to get a powered 1X riser for the 1X slot.
As for being underpowered, I think you’ll run into problems after your first 3 GPU’s. I’m currently running a rig with 4X 280X’s, all under-volted to 1.100 Vddc and I’m pulling 1150 watts at the wall. You might be able to swing 4, but you’ll be running beyond the PSU’s power spec’s and it might cause it to burn out quickly if its able to push enough wattage to power the four of them.
I have heard that you can run multiple PSU’s to power extreme rigs, but I have also read that rigs tend to get finnicky past 4 cards and 6 can be a bear to get running smoothly. Most of this is hear say though, you might have good luck!
Hope this starts to help!
The riser cables are powered yes. I have read that to get them to work properly you are better off having them powered from a seperate psu. That was news to me.
I had intended on getting another 1000w psu for the other 3 cards and joining the Psu’s together so that should be a problem.
At the moment, the main problem is that I can’t get the 3rd card to mine through the riser even though the system recognises the card and it is correctly installed. Strange.
thanks for the reply though.
Just ruling out the obvious … Do you have the pci-e power cables from the supply connected to the R9’s ?
Sure do! Got the 8 and 6 pin pci-e cable connected and then a molex into the riser.
that is strange I have 3 R 9 280 X and power them with A Seasonic 1250 XM. 1250watt supply.
Check your dummy plugs are correctly fitted?
Do you really think I would need dummy plugs? Why would two work and not the third if this was the case? I’ve not come across this on other multicard rigs.
I actually think it somehow might be video card drivers. Every time I fire up the machine my driver crashes and recovers. Last night I noticed the the third card was hashing (very slowly I might add) but once the drive crashed and recovered I got nothing. In the past, the drivers have crashed and recovered prior to me being able to start mining.
I also tried having the 3rd GPU direct on the board to rule out the riser and the same thing happened – dead/sick card.
Strange.
using 2*280x , gigabyte R9 280x rev 2.0
running both of them at 730 khs stable
downclocked to 1050 71/72C stable in a room at 21C
setting pretty much basics: -I 13 -g 2 -w 256 –shaders 2048 –gpu-engine=1050 –gpu-powertune 20
get less khs at 1080/1100 or 1000. 550khs if i start to put some TC.
so i leave it with the settings i have found/got.
Hi guys!
i have a 280x toxic. With basic settings i have theese tested:
1070/1500, 1.100V, 50%fan, 70-73temp, 310watt at wall = 740-750kh
1150/1800, 1.256V, 85%fan, 85max temp, 418-450watt = 800kh
(mono: MSI h61, Celeron g1610, 2gb ram)
I’ve downloaded the lastest VBE7 0.007b but when it says about changing the VDDC 1137 is not an option? I’ve got Sapphire R9 280X Dual-x. and followed the undervolting guide the badger used. So how come he can have 1137 and an option and I don’t see it?
Also any reason I can’t use Sapphire Trixx, just installed it and it seems simple enough?
I am seeing many more 280x rigs out there due to the increase in cost of the 7950s and the lack thereof of said cards. I have just watched as they went from 250 to over 400 a card. Now, we are forced to go with 280x’s at a less than perfect watt rate. You can see how much I am earning on my daily record page over at my site. Click my name if interested. I have a 4400 kilohash rig rolling nicely over at multipool and the results might shock you.
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Hi, i have 5 sapphire 280x vapor-x tri-x with boost cards in my rig on a an asrockh81 pro btc, two evga supernova g2 1300watt psu’s and electricity included. How do i get the most out of my setup?
Currently i’m using guiminer scrypt-win32 v0.05 in windows 8.1 64bit and getting about 670 khs per card.