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Ok so I recently started mining, first on GUIminer, then moved to CGminer. I decided to try both BTC and LTC, just for fun. however, I noticed my hashrate for BTC was ~500Mh/s so I expected about 500kh/s in LTC, yet I only get about 150kh/s. Any Ideas on what could be causing this?

Thanks in advance.

If you gave more details maybe I or people could help.

You need different settings for BTC and LTC - LTC requires higher memory speeds - you should be able to get around 600-650 kh/s for LTC mining on a 7950. Search the threads or look at some sample settings from

https://github.com/litecoin-project/litecoin/wiki/Mining-hardware-comparison

Are you sure its worth the electricity? I dont think it would be.

750 mh/s on 7970

Just check this tutorial: bitcointalk.org/index.php?topic=117221.0
It's important to add proper values of intenisty, work and thread concurrency.

firs of all set those things
comand prompt with administrator privilege
setx GPU_USE_SYNC_OBJECTS 1
setx GPU_MAX_ALLOC_PERCENT=100

now for getting 600KH with cgminer and 1100 core and a 7950 on cgminer shortcut
--scrypt --thread-concurrency 24000 --lookup-gap 2 -w 256 -I 20 -g 1

this if you want to use your pc and mining at the same time, but only 525KH
--scrypt --gpu-threads 2 --worksize 256 --thread-concurrency 8192 -I 13

Intensity setting will be different between BTC and LTC mining. Standard BTC is usually something like 6 whereas LTC can be anywhere from 12 at desktop usage to 20 for dedicated mining.

Thanks for the info! this allowed me to increase my hashrate to what it should be.

Awesome information! What voltage is your card set at when doing this?

Atm, it seems to be 1093, according to Trixx.

Hmm... what's odd is I had an issue when I ran my video card stock. I would get low hash rates with SHA-256, and if I enabled the max alloc percent variable as 100, it would give a lot of artifacts and shut down the PC after a few seconds.

I also can't seem to get my core up above around 980 without the same thing happening when on Scrypt.

Well this is fun, seems like Trixx decided to kick my GPU in the sack...I can't mine without my driver crashing. Current .bat:

cgminer --scrypt -o URL -u user -p pass --shaders 1792 --intensity 15 --worksize 256 -g 1 --thread-concurrency 21712 --lookup-gap 2 --gpu-engine 1100 --gpu-memclock 1550

Intensity at 15 because it'll cry about invalid nonces every line.

If your drivers are crashing try lowering the GPU-Engine by a little. Try 1050, 1000, and then slower decrements (like 990, 980). I found that mine works at 980 but crashes with anything higher.

Thanks, I'm working on that now ^^

BTW, is my memory clock setting ok? It's pretty much maxed out.

I don't think that should be a problem. The only issues I've run into so far were due to core speed.

Ok, managed to fix it with a couple of tweaks:

--shaders 1792 --intensity 16 --worksize 256 -g 1 --thread-concurrency 21712  --lookup-gap 2 --gpu-engine 1000 --gpu-memclock 1400

lowered the gpu engine and meclock, and upped int by 1. Going fine so far. I'll let it run for a while longer, see if anything comes up.

On a side note: the GPU seems to be running a bit hotter, might drop Int back down to prevent it.


EDIT: I rummaged through some of the CGminer options, and it lists my current gpu engine at 810 rather than the 1000 my batch file asks for. Any suggestions?

I thought this was going to be a thread asking which OP (you) should mine. Yeah you need to adjust clock speed and probably a few other hardware settings so it configures with gui miner properly.

But ALSO yes I would mine LTC lol

The faster you hash, the hotter it's going to get. Basically you're overclocking the system AND running it at max capacity 24/7. This is really where you have to decide "how hot is too hot" for you. IIRC 10c difference is essentially a 50% cut on estimated life of the device.

I prefer using 75C as my max limit, since im always afraid I'll one day wake up to find a melted 7950....

My room is somewhat hot so mine's usually at 77-79. When it hits 80 that's when I worry. Wish I had a lower ambient temperature, lol.

Completely forgot about ambience >.> i guess running over 75 makes sense when you run 2 pcs and live in a room that is pretty much a greenhouse even with windows open...

Haha, that's basically what I'm in right now. 100F+ outside, no central air, window units for AC's but I hate running the AC 24/7 so I just turn it on every couple hours for a little while to cool down the room.

This maybe the first time i WANT it to be freezing cold..

Oh, for sure. I hate the heat anyways. I love winter. If I could go anywhere it'd be Alaska...

There are so many variables when it comes to the cost of electricity. In the area that I am in, electricity is relatively cheap compared to most.  With this in mind with a 7950 and a 6850 running currently my current cost is .36 USD a day.  For me it is profitable too for others it would be not be. I would recommend getting a Kill-A-Watt and seeing what the impact is before making a decision.

http://anonymouse.org/cgi-bin/anon-www.cgi/http://img809.imageshack.us/img809/8233/bp9g.gif

i haven't tried to underclock even more, maybe it work

Very helpful image. Thanks! VDDC is the actual voltage, right? And the 7950's run at 1.250 normal?

BTC:610GH/s and LTC:680kH/s stabile on 7950 with 1150 GPU/1450 MEM.

7970 full OC

BTC: 682 mh/s
LTC 491 kh/s before crashing

for some reason cgminer with my card is extremely unstable, can't make it work with two gpus' in the same case and crashing after OC is normal

case is bigtower, well ventilated... I will change cooling for gpu anyway.

I think you should check the VRM instead of the GPU, it can melt much faster.  ;)
My 7970 can have 70C GPU with 100C+ VRM easily with extreme loads, like mining, when overclocked....

Core voltages are set as (1mV per 1MHz)+10mV, and my memory voltage is brought down to 1500mV.

I use a ratio of Clock Speed x 1.535 = Memory Speed. Intensity = 20, concurrency = 22,400, 1 GPU thread.

955/1466 -> 565 - 580kh/s
977/1500 -> 585 - 595kh/s
1010/1550 -> 590 - 615kh/s
1043/1600 -> 605 - 635kh/s
1075/1650 -> 640 - 658kh/s
1113/1700 -> 670 - 680kh/s
1140/1750 -> 675 - 695kh/s

The slower of the two is the launch day model, and is probably slower because it's displaying my desktop at a 144hz refresh rate. I can only run the cards at 700+kh/s during the winter when my ambient temps are 60F or lower.

I just found out that apparently I can't change the voltage on my card (Trixx shows the changes, but GPU-Z and CGMiner both show the stock voltage). Along with this, I can't change the memory clock speed (Trixx again shows what I set it to, but CGMiner and GPU-Z show different).

That sucks, :(.

Many cards are voltage locked, many aren't.  Try again using MSI afterburner with unofficial overclock mode turned on.  If that fails, see if you can flash your card's bios to another with a lower voltage setting.

Furthermore, cgminer always shows incorrect GPU voltages for my card.  It will show 1.25v even when I'm running at 1.0v

yeah is the voltage,  and 1250 is the default ram, i just overclocked the core, is more stable in this way

LTC hashrate is superior.

Thanks I just changed mine to 75C on max limit, appreciate it.