Re: Undervolting Via Custom BIOS / Firmware (7950 / 280x) \[Working\]
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Just an update.
I gave the F43 bios a shot, no go. Didn’t boot. I tried one from techpowerup. It was mining but it didn’t show up in BAMT, and the fan and temp sensors wern’t working…
I then tried another one listed. [url=http://www.techpowerup.com/vgabios/134922/sapphire-hd7950-3072-121220.html]http://www.techpowerup.com/vgabios/134922/sapphire-hd7950-3072-121220.html[/url]
And it works! ;D I’m now at 1.094v :)
Now just to do the other card, at thats currently sucking down 1.256v.
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Update: I just flashed the same BIOS onto the card which was sucking down 1.256V, it’s now at 1.169v.
I’m not sure why it didn’t drop down to 1.169v like the other one did!
But overall I’m saving 100W total. And they’re running much cooler and quieter, so I’m happy with that :)
GPU 0 went from 1.256 -> 1.169v
GPU 1 went from 1.169 -> 1.094vWith the exact same BIOS and settings. Interesting.
Now just to do similar to my 280x toxic!
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[quote name=“mattmct” post=“52593” timestamp=“1389851516”]
Now just to do similar to my 280x toxic!
[/quote]I’m watching :D
Just sent an MSI 280X back as it ran like a hover on over load and sucked more juice than a 4 year olds birthday party!!! So when they have sorted that out, I’ll get another Toxic to add to the 2 already in the rig and then thats me for hardware investment (I’ve promised the other half) so then I will concentrate on getting the hash/w ratio as best as I can
UM
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Hey Muddy, I’m glad I can help you out in return for your help :).
I got my voltage down on the 280 toxic, runs so much cooler and quieter now. I manually modified the BIOS, and set it at 1.1V. Wayyy better than the 1.256V…I can set it lower, but haven’t had time to play yet.
I followed this guide. [url=http://rumorscity.com/2014/01/03/litecoin-mining-sapphire-radeon-r9-280x-sweet-spot-for-740khashsec/]http://rumorscity.com/2014/01/03/litecoin-mining-sapphire-radeon-r9-280x-sweet-spot-for-740khashsec/[/url]
I saved my firmware (as backup), then flashed the BIOS linked on the page. I then loaded up the BIOS on my PC using VBE7 to change the voltage from 1081mV to 1010mV.
It’s easier than it sounds! And gives you exact control. I unpluged my other GFX cards when I was flashing, and did one by one, JUST incase I flashed the wrong one lol.
I’ve yet to have time to play with cgminer settings to get the 280 working with two cpu threads, and keeping the single thread on my other two 7950, I’m assuming I need to run two cgminer instances, and disable one card in one, and the other two cards in the other.
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[quote name=“mattmct” post=“52999” timestamp=“1389986745”]
Hey Muddy, I’m glad I can help you out in return for your help :).[/quote]No worries glad I could be of some help to someone
[quote]
I got my voltage down on the 280 toxic, runs so much cooler and quieter now. I manually modified the BIOS, and set it at 1.1V. Wayyy better than the 1.256V…I can set it lower, but haven’t had time to play yet.[/quote]Now this give me a little more confidence to have a go at one of my cards for sure :P
[quote]
I followed this guide. [url=http://rumorscity.com/2014/01/03/litecoin-mining-sapphire-radeon-r9-280x-sweet-spot-for-740khashsec/]http://rumorscity.com/2014/01/03/litecoin-mining-sapphire-radeon-r9-280x-sweet-spot-for-740khashsec/[/url]
[/quote]
Did you get the magic 740Kh/s? and do you know what your pulling at the wall?
[quote]
I saved my firmware (as backup), then flashed the BIOS linked on the page. I then loaded up the BIOS on my PC using VBE7 to change the voltage from 1081mV to 1010mV.
[/quote]
Wise move, I will have a go, when my back stops giving me so much grief all I can do is lay down >:(
[quote]
I’ve yet to have time to play with cgminer settings to get the 280 working with two cpu threads, and keeping the single thread on my other two 7950, I’m assuming I need to run two cgminer instances, and disable one card in one, and the other two cards in the other.
[/quote]Simple it’s all in the cgminer.conf file!
If the line in your file looks like this
[code]“gpu-threads†: “1″,[/code]
Change it to something like this
[code]“gpu-threads†: “1,1,2,2″,[/code]
The numbers go GPU0,GPU1,GPU2,etc… Make sure that you have a comma between each number and that there is no comma between the last number and the quotation mark and a comma after the quotation mark or your rig will through it out and cgminer won’t start.
The same goes for any line in your config file, so you can have cards with different everything if you want, the only exception I have found is pools, Somedays I think it would be nice to mine different pools with different cards but hey you can’t have everything.
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[url=http://www.cryptobadger.com/2013/10/undervolting-in-linux-via-modified-bios/]http://www.cryptobadger.com/2013/10/undervolting-in-linux-via-modified-bios/[/url]
Follow the step and flash your own bios that you rip, its much safer and efficient I believe.
For the 7950 im undervolting to 1.087 and getting 630 kh per card at 68 degree with an external fan.
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[quote name=“kojima18” post=“53046” timestamp=“1389997116”]
[url=http://www.cryptobadger.com/2013/10/undervolting-in-linux-via-modified-bios/]http://www.cryptobadger.com/2013/10/undervolting-in-linux-via-modified-bios/[/url]Follow the step and flash your own bios that you rip, its much safer and efficient I believe.
For the 7950 im undervolting to 1.087 and getting 630 kh per card at 68 degree with an external fan.
[/quote]Yeah that’s exactly what I did and said. But good guide!
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Ah yes sloppy reading, Cheers
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Muddy,
I’ve yet to really play with any settingd due to no time right now, and not tried his recommended yet.
I’m getting about 620Kh/s right now but im sure I can push further. (from the 280x)
My three cards are pulling about 780W-795W, at the wall on my 750W PSU (rather at 80% efficiency) so I’m guessing it about to pull about 900W at the wall. When I was running with my two 7950’s alone it was about 650W (if I remember correctly) so thats about 140-150W for the 280x…if the 650W was correct. Before I undervolted my cards, they were pulling 950W - 1K on my 750W PSU lol. I’d say I’m saving at least 50W per card now I’m undervolting.
Thanks for the cgminer.conf info, I’ve already tried this with no luck :/… from checking screen -r on the cgminer, it only shows one thread per card.
Edit: ! I just noticed my config file says, “gpu-thread”…where as you wrote “gpu-threadS”… I’m hoping it will be that simple! lol
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no luck again :/
Using “gpu-threads” : “2,1,1”, and also trying “gpu-thread” : “2,1,1”, No luck. cgminer under gpu managment shows just three threads, one for each card :( 0,1,2
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After playing with it for some time, I’m now 100% sure that you can’t mix threads in one cgiminer instance.
I can get two threads working on all three cards at once, (with lower thread count to stop it crashing), or 1 thread on all cards, but not a mix. if I do “2,1,1”, it just does one for all :/.
I’ve read this in a few places over the last week or so. I’m pretty sure I just confirmed it.
The only way I can I can do it is:
Run one cgminer for the two thread 280…by disabling the other two cards?
Ran a second cgminer for the single threaded 7950’s by disabling the 280x in that instance?Now just to work out how to do that in BAMT / BAMT SMOS.
I’m thinking the -d flag, but I’m having a hard time finding any info.
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My 2 Toxics running at 740 steady volted at 1.1 are pulling 650 at the wall, I don’t have a 3rd just yet might fix that tomorrow at some point with a little drive out ::)
I’m sure I have seen somewhere that the threads can be configured like that. I had some problems with my Toxic’s early on when trying to run 2 threads they would just bomb out! Then I tweaked the mem and clock speeds a little more and managed to get it running and displaying as 2 threads! Never did work out what that was about.
If your thinking I can get 50W a card less without messing the hash up then I will be very impressed! Just under 1.5Mh/s for around 550W that would be a big result for me.
I’ll have a play tomorrow at some point and see where I get to with it before I have to off ski for work next week :(
UM
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I’m really not sure about mixing the gpu threads, I read somewhere that it only takes one input. I’m really hoping that isn’t the same.
I got it to bomb out also on all my cards when the thread count was too high, but then I reduced it and all three cards were running 2 threads each. But can’t get a mix of the gpu threads yet.
I need a good time on the tuning, real work getting in the way, I have tons of videos to edit…
What are your current settings for your 280 toxic if you don’t mind? I’m just using my 7950 congif right now, as have been just trying to get the two threads working before I tweak much else.