Consolidated Litecoin Mining Guide for 5xxx, 6xxx, and 7xxx GPUs

[tacotime]

No, you can use whatever you want with 7950. I'd suggest CGminer, you just have to tweak a couple of things. First of all, you Can't go over 13 intensity for starters. Set shaders, set vectors for 1, set lookup gap to 2.

For 7950 the sweet spot should be around 1.33 core to memory ratio.

Just used the new version of cgminer this morning, core:mem ratio of 0.68, only got 280 kh/s per card with all those settings.  The 7970s and 7950s are very different with cgminer.

[kronut]

Thanks for sharing your settings, helps quite a bit switching over to litecoin with higher end cards.

I'll share my 6770 settings that get 200kh/s+ :

12.1 and SDK 2.6

"intensity" : "18",
"vectors" : "1,",
"worksize" : "256",
"kernel" : "scrypt",
"lookup-gap" : "2",
"thread-concurrency" : "4100",
"gpu-engine" : "960-960",
"gpu-memclock" : "1200",

Note that you cannot use the machine for anything else with i18, if you switch to i14 it's perfectly usable at 180kh/s.

[tacotime]

Updated cgminer settings for 7970

[meebs]

One thing is for sure, different shader amounts of different cards in one machine are not a good idea.

I can't for the love of god can make my 7970 work alongside a 7870 properly. The problem is NOT with the 7970, that hashes away 700-750 perfectly.

Are you running two different reaper instances?

I mine with a 7950 and a 7870 just fine.... 650 on the one and 400 on the other.

And by different instances I mean two completely seperate folders each configured seperately with a shortcut to each on the desktop

Try that out and let me know if it helps you at all...

ps. both cards are the tri-fan gigabyte models, not sure if that makes a difference...

[Scratch]

One thing is for sure, different shader amounts of different cards in one machine are not a good idea.

I can't for the love of god can make my 7970 work alongside a 7870 properly. The problem is NOT with the 7970, that hashes away 700-750 perfectly.

Are you running two different reaper instances?

I mine with a 7950 and a 7870 just fine.... 650 on the one and 400 on the other.

And by different instances I mean two completely seperate folders each configured seperately with a shortcut to each on the desktop

Try that out and let me know if it helps you at all...

ps. both cards are the tri-fan gigabyte models, not sure if that makes a difference...

Dont need two folders, just shortcut one to reaper1.conf which points to litecoin1.conf and the other to reaper2.conf which points to litecoin2.conf. eg: For my 5770 its "C:\Mining\REAPER\reaper.exe reaper57.conf"

[-ck]

Just a few notes about cgminer that seem to be forgotten with scrypt...

Changing vectors does nothing.
Default lookup gap is 2, so setting 2 or 0 does nothing.
Default gpu threads are 2, so setting 2 does nothing.
Setting thread concurrency overrides shaders, so if you set thread concurrency, setting shaders does nothing.
Intensities over 13 for 79x0 just drops the hashrate or generates garbage so don't do that.
Magic core:mem ratios seem to be entirely hardware dependent: motherboard/CPU/GPU combos change it even for the same 79x0 device.
Magic core:mem ratios work much better on windows. On linux they don't seem to be anywhere near as effective.
Running CPU frequency scaling on linux (or the equivalent on windows) will slow down your GPU hashrate a little, so set your CPU to maximum performance equivalent.

[flound1129]

Just a few notes about cgminer that seem to be forgotten with scrypt...

Changing vectors does nothing.
Default lookup gap is 2, so setting 2 or 0 does nothing.
Default gpu threads are 2, so setting 2 does nothing.
Setting thread concurrency overrides shaders, so if you set thread concurrency, setting shaders does nothing.
Intensities over 13 for 79x0 just drops the hashrate or generates garbage so don't do that.
Magic core:mem ratios seem to be entirely hardware dependent: motherboard/CPU/GPU combos change it even for the same 79x0 device.
Magic core:mem ratios work much better on windows. On linux they don't seem to be anywhere near as effective.
Running CPU frequency scaling on linux (or the equivalent on windows) will slow down your GPU hashrate a little, so set your CPU to maximum performance equivalent.

Thanks that helps

Is there a .conf setting to not submit stales or is that only command line?

[-ck]

Just a few notes about cgminer that seem to be forgotten with scrypt...

Changing vectors does nothing.
Default lookup gap is 2, so setting 2 or 0 does nothing.
Default gpu threads are 2, so setting 2 does nothing.
Setting thread concurrency overrides shaders, so if you set thread concurrency, setting shaders does nothing.
Intensities over 13 for 79x0 just drops the hashrate or generates garbage so don't do that.
Magic core:mem ratios seem to be entirely hardware dependent: motherboard/CPU/GPU combos change it even for the same 79x0 device.
Magic core:mem ratios work much better on windows. On linux they don't seem to be anywhere near as effective.
Running CPU frequency scaling on linux (or the equivalent on windows) will slow down your GPU hashrate a little, so set your CPU to maximum performance equivalent.

If you want a video, me setting vectors 1 to 2 raising my 7870 to 410 instead of being on 350, without hw errors, let me know. Vectors indeed make a difference, sorry.

Considering I wrote cgminer, and that the vectors value isn't even passed to the kernel, I think I'd know.

[-ck]

Found a nice awkward bug and the next version of cgminer will fix the high thread concurrencies limitation on 79x0 devices and the intensity 13 limitation.

[Flatlinezor]

Found a nice awkward bug and the next version of cgminer will fix the high thread concurrencies limitation on 79x0 devices and the intensity 13 limitation.

Oh yeah, I did not check the name sorry. It makes a difference in reaper, not cgminer, I forgot to mention. But I am telling you the truth trust me Also, very good work on cgminer, and if the next release will indeed lift the intensity/concurrency issue, i'll get back right away from reaper on one of my cards, because the stratum support absence is a pain, applying the proxy all the time. Keep up the cool work!

[sgravina]

I'm switching to litecoin.

Running 2 5870's on a Windows 7 with i7 and 8 GBytes memory.

Code:

cgminer-2.11.2-win32\cgminer ^
--scrypt ^
-o http://newlc.ozco.in:9332 -u username -p password ^
-o localhost:9332 -u username -p password ^
--auto-fan ^
--shaders 1600 ^
--worksize 256 ^
--intensity 18 ^
--gpu-engine 900 ^
--gpu-memclock 1300 ^
-g 1

This works good.  I get 415 KHases/sec from each card.  But if I set "-g 2" then it crashes.  No question here, just sharing.

Now on my Linux box, AMD 2 core Athlon, 2 GBytes Memory. Three 5870 and a 5850.  This works:

Code:

  cgminer \
    -o http://newlc.ozco.in:9332 -u username -p password ^
    -o localhost:9332 -u username -p password ^
    --scrypt \
    -g 1 \
    --auto-fan \
    --shaders 1600,1600,1600,1440 \
    --worksize 256 \
    --intensity 16 \
    --gpu-memclock 1200,1200,1200,1200 \
    --gpu-engine 800,800,800,775

But on an almost identical machine it won't work.  Even though I tried a lot of variations of the shown parameters, plus --thread-concurrency.  Why?

Would adding more system memory help?

[matauc12]

I just want to advice people, although the gigabyte 7950 WF3 looks like a good buy, its complete POS. They come with a hardware locked core of 1.25 (default is supposed to be 1v ish) none of them over clocks higher than 1000/1450 and they run at 80c.

I have 5 of them unfortunately So getting roughly 580khs from cards that could get much more.

[-ck]

Found a nice awkward bug and the next version of cgminer will fix the high thread concurrencies limitation on 79x0 devices and the intensity 13 limitation.

Oh yeah, I did not check the name sorry. It makes a difference in reaper, not cgminer, I forgot to mention. But I am telling you the truth trust me Also, very good work on cgminer, and if the next release will indeed lift the intensity/concurrency issue, i'll get back right away from reaper on one of my cards, because the stratum support absence is a pain, applying the proxy all the time. Keep up the cool work!

I'm not sure you want to hear this, but the scrypt kernel in reaper is the same as in cgminer, and it also does not do anything with vector parameters for litecoin mining (strictly speaking, both kernels are fixed to 4 vectors internally).

Anyway thanks. Test builds can be found on the cgminer forum thread.

[tacotime]

Found a nice awkward bug and the next version of cgminer will fix the high thread concurrencies limitation on 79x0 devices and the intensity 13 limitation.

What was it? I'd like to fix the reaper kernel too if it was a problem with that.

[tacotime]

I just want to advice people, although the gigabyte 7950 WF3 looks like a good buy, its complete POS. They come with a hardware locked core of 1.25 (default is supposed to be 1v ish) none of them over clocks higher than 1000/1450 and they run at 80c.

I have 5 of them unfortunately So getting roughly 580khs from cards that could get much more.

None of mine are hardware locked. I'll try and post a pic of my pcb after, wondering if they did a silent revision.

[matauc12]

I just want to advice people, although the gigabyte 7950 WF3 looks like a good buy, its complete POS. They come with a hardware locked core of 1.25 (default is supposed to be 1v ish) none of them over clocks higher than 1000/1450 and they run at 80c.

I have 5 of them unfortunately So getting roughly 580khs from cards that could get much more.

None of mine are hardware locked. I'll try and post a pic of my pcb after, wondering if they did a silent revision.

I googled and apparently its most that have been bought after December. Has the fx0 bios flashed on both CMOS.

Should also note this crappy new revision also comes with 8pin + 6pin vs 6pinx2

I'm trying to return them and get 3x7970 instead. Will be 300$ more for basically 500khs more, and better resale value. And probably much less hassle too. These 7950s are awful all around. Their temps are alarming, and cause instability. I'd always feel on the edge when leaving for a week (which I often do)

[stevegee58]

I just started tinkering with LTC mining last night with me 6770 and cgminer.

Man, it's like learning to crawl all over again.

[matauc12]

I am looking to populate 7 empty slots I have, and because of power requirement mainly (and looking at the possibility of cheaper alternative), I am wondering, as there been any significant reports (across this thread probably) about 7870 LE (XT) Tahiti LE? I have heard a couple people claim 500khs no OC. If that is the case, it might be my next purchase, but they really need to do 500khs guaranteed to be profitable.

[kronut]

I just started tinkering with LTC mining last night with me 6770 and cgminer.

Man, it's like learning to crawl all over again.

That's half the fun though, tweaking your cards to get the highest rate, at the best power consumption, it's like starting the BTC train all over like you said.

[Scratch]

I am looking to populate 7 empty slots I have, and because of power requirement mainly (and looking at the possibility of cheaper alternative), I am wondering, as there been any significant reports (across this thread probably) about 7870 LE (XT) Tahiti LE? I have heard a couple people claim 500khs no OC. If that is the case, it might be my next purchase, but they really need to do 500khs guaranteed to be profitable.

With a 7870 I get 370, you have a fair chunk more shaders so it would seem possible yes. Obv cant confirm though.