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

[philips]

Might be interesting:

just found out the scrypt cgminer crash, if compiled with -O2 the optimations lets it segfault, with -g it works fine.
gonna send u the core + binary per PN.

Can't debug something unless it's with -g as well. -g shouldn't change the risk of crashing, but going from no optimisations to -O2 might.

sry, forgot to add the -g

Thanks to K1773R I was able to debug this crash. What's more interesting is this was also responsible for scrypt not being able to set thread concurrencies higher than 9999 on cgminer. So there is a fix for this bug in git now, and I have also confirmed I can now set thread concurrencies as high as 12288 on my 7970s... though it did not improve their hashrate at all. However at least it solves that mystery.

[tacotime]

I will update my cgminer and try this now.

edit: Not fixed yet in win32 binaries

edit 2: ckolivas fixed version still doesn't permit high thread-concurrency values, it reports that 2^29 is the max buffer size to use as always

[Scratch]

I found out how to get 390k/hash from a 7870!!!

essentially you treat it JUST like tacotime did with his 7770's...

Why? a 7870 is almost exactly a "double" 7770... double the shaders, and double the memory bandwidth.

No matter what I tried before, I could never get above 320 khash.

Downclocking the core all the way to 920 while bumping memory up to 1360 did the trick along with intensity 19.

Funny thing is... raise the clock to 1000 and the mem to 1450... 310 khash....

LTC mining is truly an art...

Hi Meebs,

I've just gotten into mining using my 7870. Up to 365kHashes at full blast. Just wondering what your full config is.

Ty.


@Everyone: Got my brothers 6850 doing 270ish kHash, how much more could I get from it.


Worked out how to set up the configs for light/medium/heavy Reaper setups(having to link reaper.conf's to litecoin.conf's tricked me for a sec) so I can run at about 70-100 kHash all the time and then ramp it up when I'm out.


Am I right in saying forget CPU? I seem to lose the same amount from Reaper as a I gain in Scrypt with more heat output.


Fun new hobby this is.

[tacotime]

The later drivers/app sdks seem to get a little less kh/s for me (although also less stales), so I'm not sure if you can get more out of those cards.  270 KH/s is pretty good for a 6850, I used to get 290 KH/s out of my 6870.

And, yeah, don't bother with CPU mining, it's a waste of electricity as GPU mining is about 5-6x more efficiency.

[Scratch]

The later drivers/app sdks seem to get a little less kh/s for me (although also less stales), so I'm not sure if you can get more out of those cards.  270 KH/s is pretty good for a 6850, I used to get 290 KH/s out of my 6870.

And, yeah, don't bother with CPU mining, it's a waste of electricity as GPU mining is about 5-6x more efficiency.

Thanks Taco.

One last thing. Was gonna use litecoinpool.org or whatever its called but it was full so I'm on notroll.in. Have they a decent reputation among the community?

[xorxor]

notroll.in is fine, stratum -  very low stales, but im getting around 1-3% invalids. it is the pool i was using when coinotron was down. coinotron is the best in my opinion but notroll is a very very close second. I use 2% rbpps on coinotron now. 

[tacotime]

One last thing. Was gonna use litecoinpool.org or whatever its called but it was full so I'm on notroll.in. Have they a decent reputation among the community?

Notroll is what I use

notroll.in is fine, stratum -  very low stales, but im getting around 1-3% invalids. it is the pool i was using when coinotron was down. coinotron is the best in my opinion but notroll is a very very close second. I use 2% rbpps on coinotron now.  

I get 0.4% stales and no invalids on notroll.in using stratum, play with your settings

[KrLos]

Man i send you 1 ltc, i know is too litle, but i wanna thank you in some way.

I got an 6850, and i'm getting 250~300 kh/s without the ams-app-sdk, i'm downloading it now, let's see what happend next xD

Thanks, and sorry for the litle amount of ltc sended.

Bye

[Scratch]

Ok, so we're re-evaluating things.

Current plan:
Mine Litecoin(lower difficulty, no ASICS) - buy BTC - buy stuff.

Considering changing to:
Mine Bitcoin - buy stuff.


Which is going to be more effective with low end hardware(7870, 6850, few other bits)? There's talk of litecoin values improving with time but I dont know enough about any of that.

As of right now its 445 LTC to one bitcoin, thats a fair bit of mining, but bitcoin mining is slow as hell though...so. What do ya'll think?

[tacotime]

I can't tell the future -- I mine litecoin and hoard, been doing the same thing since release over a year ago.  BTC difficulty is going up quite a bit because of ASICs; at some point GPU miners will either move to LTC or move on with their lives.  If a lot of GPU miners move to LTC, then LTC price will probably skyrocket.  If not, it won't.  It's up to you, cryptocurrency prices are terribly erratic.

[kokojie]

I can't tell the future -- I mine litecoin and hoard, been doing the same thing since release over a year ago.  BTC difficulty is going up quite a bit because of ASICs; at some point GPU miners will either move to LTC or move on with their lives.  If a lot of GPU miners move to LTC, then LTC price will probably skyrocket.  If not, it won't.  It's up to you, cryptocurrency prices are terribly erratic.

I don't really understand your logic, why would price skyrocket with more miners? difficulty follows price, not the other way around.

[tacotime]

Not sure where this belief comes from, but sometimes difficulty follows price and sometimes price follows difficulty.  Previously with BTC price was the driver in the majority of the cases, but it's not always true.  LTC has been different because of the rapid adjustment algorithm too.

BTC price skyrocketed four months after GPU mining was introduced and the hash rate/diff was already way up, I wouldn't be surprised if similar happened for LTC (first OCL mining software was released on October 1st 2010, hash rate shot up like crazy, followed by price in 2011).  Throughout 2010 it's clear that higher network hash rate/difficulty preceeded higher prices.

[Scratch]

Whats the BSD column on notroll do you know Taco? Surely cant be Blue Screen Of Death?

[tacotime]

BSD = the difficulty of the "best" share you have submitted since the last found block.  But I don't think it's ever worked since it's been added, mine is always 0.

[Scratch]

BSD = the difficulty of the "best" share you have submitted since the last found block.  But I don't think it's ever worked since it's been added, mine is always 0.

Same, 0 across the board(only found 3 blocks anyways). Cheers.

[Scratch]

Can anyone explain why GPU usage will max out no matter what the aggression or concurrency? It would be nice to run my card a little cooler while on my "medium" profile?

Update: Trialing the 5770 simultaneously. Got it working really well except a load of heat is being pushed onto the chipset and its heating that too much and causing the chassis fan to have to go full tilt :/ Need to get myself some decent 120s for the roof and a fan controller. 

[tacotime]

The GPU will try to use all threads even with the lower difficulty.  The easiest way to lower heat is to reduce the voltage, if your cards allow you to.

[Scratch]

Yeah, I've been working on minimising them.

Real change would be to get a nice big noctua fan in the roof though.



That IO controller in the back is getting too hot. Probably would be better having reference design coolers as all the hot air would be expelled from the case.

[exahash]

I'm working on converting 18 rigs with about 80 5850's to LTC mining and am looking for optimal settings.  Anyone care to share?

Here's what I've found so far:

My rigs are all running Ubuntu 11.04 x64 server with SDK 2.4 and cgminer 2.10.5a from kano.

My cgminer cmdline is:
cgminer --scrypt -w 256 --thread-concurrency 7200 --intensity 20 -g 1 --lookup-gap 2  --no-submit-stale --no-restart

I built that cmdline from reading ck's readme files.  Pools are Notroll.in and litecoinpool.org in that order.

I am testing with a smaller rig for now (only two 5850s).  The cards are oc'd slightly to 810/1000 and 820/1000 respectively.

I'm getting 341 kh/s and 345 kh/s respectively, but they bounce down into the 300's every so often as I get stratum disconnects from NoTroll.in.

After reading this entire thread, I'm wondering a few more things:
- What's the big difference between SDK 2.4 and 2.6?  I'd probably reformat and move them all to 12.04 and current SDK rather than 2.6 if its a big difference.
- Why do you recommend thread concurrency 7168 instead of 7200 (a 5850 has 1440 shaders x5 = 7200)

I see people referring to tweaking scrypt mining as an art... what's the current state of the art for 5850's?

[meebs]

Remember kids: TacoTime has his cards in the damn arctic.

When I run LTC mining at 1050/1.08V my VRM's run in the 90's... (core 70's)... THat said.. 640 khash each isn't to tough to get on a 7950.. just be careful so ya dont eff up your cards