Topic: Consolidated Litecoin Mining Guide for 5xxx, 6xxx, and 7xxx GPUs - page 26. (Read 624200 times)

Raising GPU threads will not increase thread_concurrency indirectly, it just adds another thread calling the memory and working the ALU.  In reality the GPU scheduler seems efficient enough that by just setting one thread, we get pretty good values for hash rate (usually the same or better than 2 threads for all my cards).

You should be using either shaders or thread-concurrency, not both.

You can't really configure thread-concurrency above 8192 in cgminer.  I have not found this to be a problem on my 7970.  I just increased gpu_threads to 2 to compensate.

The easiest way to see an example of the config is to have cgminer write out its running config.  The config variables will look like this (card1, card2)

"intensity" : "13,12",
"vectors" : "1,1",
"worksize" : "256,128",
"kernel" : "scrypt,scrypt",
"lookup-gap" : "0,0",
etc.

Would CGminer allow me to raise the thread concurrency over to 16384 on a 2gb 7870, while the 7970 uses 8192 as thread concurrency? I know different intensity vlaues can be launched, that is fine. But in order to have 19ish intensity, i HAVE to raise the thread concurrency a lot. As far as I gathered, it is either shaders or thread concurrency that drives the amount of memory being allocated for certain intensity's without overwriting the already used ram data.

Can you give me an example of two separate configs for two cards please?

stale will probably never be 0 but GPU errors are a sign of something wrong.  That said if you are getting decent hash rates I wouldn't lose any sleep over it.  You could try tweaking the thread_concurrency and see if that makes the HW errors go away.

You can set different config values for different cards in cgminer.conf.  Have it write out a config for you and you'll see how it's done.

Finally I could decently mine my 7850 with this configuration:

worksize 256
aggression 16
threads_per_gpu 1
sharethreads 18
lookup_gap 2
gpu_thread_concurrency 8500

This is what i got:

354,2 kH/s, shares 123:3, stale 2,362%, GPU errors 0,07252%, ~348,139 kH/s

Must stale and GP errors be 0?

Thanks!

Me neither, too much time consumed building rigz 

@Taco: Whats with the two different hashrates that reaper reports? What does each represent?

Tried to game with LTC going, 5770 mining while 7870 running World of Tanks, performance was fine but the latency was terrible, too many packets to the pool.

Also a LoL player but havent been playing the last few months.

Thanks, i'll give it a go when I get home. My main card is the 7970, so I would not mind to stress the hell out of the 7870 on whatever intensity, because it would not cause issues. And the 730ish khash on the 7970 with 13 intensity allows me to even game if needed without major khash loss (league of legends deducts only 100mhash when it is BTC, i haven't tried gaming with LTC mining yet.)

Sapphire 7870 btw if you wanted to know. Nice box, that's all

Running .938v 850/1250. Found going any higher was pointless, dont get increased hashing.


When I'm using the rig: (About 260 and totally usable, HD playback and dual display)



I'm pitcairn too btw, RoyalKing 2GB.

Give 1000/1660 a go, intensity 13, it'll be over 700 You can go vcore 1050 with that easily.

Temps are 49-51 for both cards, they are on water I'll try two reaper instances with two configs, but frankly, I like cgminer better, more information on screen and more easily configurable.

What I'd really wanna know is if PCIE slots might cause issues for the 7870 stability, or something like that. I have the best mainboard kind of that money can buy, an asus maximus extreme V with 5 pcie slots all capable of 16x almost.

I'm really uneasy about the 7870 resetting itself on higher intensity. Although I'll give the 2 instances of reaper a go.

If nothing helps, i'll manually overclock the two cards via the starter batchfiles and make a script that restarts the 7870 reaper client every 20 mins, or something like that. I'll lose a few shares, but better than not mining at all

For me, the 7870 crashes at 420ish khash with reaper every 20 mins. and it is NOT the overclock I am sure. What is your minimum voltage on 7870? Mine is not a Tahiti core, but a pitcairn one unfortunately :/ And no, i get GPU errors right away IF i set the intensity to anything over 13 in cgminer. No hw errors at all at 20 aggression in reaper, but it resets every 20 mins anyway.

Any ideas? With bitcoin, the 7870 hashes away at 430mhash without any issues or complaints. LTC mining on those 2 different cards of mine is tricky. BTC mining is not at all.

Oh and I'd stick to cgminer with the 7970 if possible, because I have a lot better hashrates on it than on reaper with the 7970 :/

I'm running a 7870 and 5770 together. Running full tilt they do 370kH+170kH. Both undervolted, if I go too far the driver crashes after while and the voltage resets(thus nasty temps) but other than that it keeps on going(longest Ive done it is about 36hrs cause I do use the rig).

Got two reaper instances, use shortcuts with different reaper configs that lead to different litecoin configs. Had to delete the bins a few times while configuring it the first time.


What are your temps like? I would think you might be having a cooling issue if it takes 20-30 mins to freak and you get GPU errors. Just because the core is within check doesnt mean the whole board is btw.

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.

The issue is with 7870. It stops around 350khash, although when I set intensity in cgminer to 20, it'd reach 420ish, but then I get constant hardware errors. Hell, I even have HW errors ate Intensity 14, even on 13, if the shader amount is 2048, as specified for the 7970. Multiple shaders amounts tried, did not help.

The problem is, reaper works fine with only the 7870, it hashes 400 stable, but it resets the display driver every 20-25 minutes, maybe sooner. Can I raise stability somehow there? It does reset the display even on default clocks, when I'm not aiming for the best hashrate to be found... Intensity 19 and 20 seem to just kill the driver, although there is NO hw error with reaper, because it can handle the larger than 8192 thread concurrency.

I would not have a problem mining one card with cgminer and the other with reaper, but this reset thingie is not good. I am using 12.8 at the moment I believe, should I try to go for the beta drivers?

Any advices? Also, my peak performance on the 7970 comes when I'm 1660memory and 1000 core. Not lower, as most people experience :/

Also, did anyone undervolt 7870 and to what extent? I think 1.2 is a lot compared to the 1030 my 7970 can handle.

Im using GUIminer for scrypt (cgminer) and I get roughly 440kh/s out of my non modded (no bios flash), non reference 1GB 6950.

Its set for 18 aggression and other default values for the 6950, and my clocks are 900/1250, I manually set fan to 67% and temps are around 80c

Quite sure it will make absolutely no difference.

its pretty easy actually...

for your hash rate.. calculate how many LTC you will get in a day... multiply that by the BTC exchange rate.

If you get 0.15BTC.. then you compare it to how many BTC a day you get mining BTC.. if that is 0.10.. you have a profitability of 150%

reaper.conf
kernel reaper.cl
save_binaries yes
enable_graceful_shutdown no
long_polling yes
platform 0
device 0
cpu_mining_threads 0

mine litecoin

litecoin.conf
host litecoinpool.org
port 9332
user user.1
pass 1

protocol litecoin

worksize 256
aggression 13
threads_per_gpu 1
sharethreads 16
lookup_gap 2
gpu_thread_concurrency 16500

Post your reaper.conf here, you should be able to get at least 200-300 Kh/s on a 7850