Bitcoin / Litecoin Mining Experience + Small issue

[CoolIT]

I was just thinking of writing up my mining experience, in case it can help out any newbi miners.
I like to think my setup is probably one of the least complicated, more specifically regarding my choice of software.


Originally I had my machine mining Bitcoins at 900 Mhash but due to the steep difficulty, I decided to switch over to litecoins, to then exchange for bitcoins.

As I live in Quebec Canada, I gave a shot to cavirtex.com
I sent them my bitcoins, converted them to Dollars and gave myself a direct deposit. Works nice and easy.


Here are my specs:

Sempron 140 (2.7Ghz Single core)
MSI 890fxa-gd90 (6 PCIE slots)
Originally 2 gigs ddr3, now 6. (1x1 + 2x2)
700W PSU of reliable brand.

0-0 Radeon 6950     900Mhz clock   average temp 85 degrees  1408 Shaders
0-1 Radeon 6950     940Mhz clock   average temp 70 degrees  1408 Shaders
0-2 Radeon 6570     725Mhz clock   average temp 70 degrees  480 shaders
0-3 Radeon 5570     680Mhz clock   average temp 90 degrees  400 (I know it's high but I don't care, I got another 6570 laying around)

The above ran reliably for 1 month and a half and got me 3 bitcoins.
So the machine paid itself off already.

The software config is the following.

Windows 7 Home X64
Catalyst 13.1 drivers
I have mined reliably at very fair speeds using GUIMiner V 2012-12-03
I used slushpool for pool mining.

I would execute GUIMiner once for every card.
On all cards I added the following Extra flags -v -f0 -w128
The 6950's performed 350 to 380Mhash
The 6570 did 100Mhash
The 5570 did 75Mhash

Overclocked using Trixx
Monitored using GPUZ
__________________________________________

Now, for the litecoin change.

This gave me a bit of trouble.

First, I upgraded my RAM to 6 gigs as I read litecoins are ram intensive.

I signed up to coinotron.com and built my new workers.

account.r6950a
account.r6950b
account.r6570
account.r5570

I tried EasyLTC
Nice looking application, but no matter what I tried, it never worked for me. (sorry)

I tried CGminer
The one with the script that helps out, or manually
cgminer --scrypt -o coinotron.com:3334 -u account.r6950a -p password --shaders 1408 --intensity 13 --worksize 128 -g 1
different variations of the code... Nada... same issue. (I also didn't find where to manually specify what GPU to use.)


Finally I got it working with GUIMiner-scrypt alpha
Version V0.02 by TacoTme

Here are my settings:
Host: coinotron.com
Port: 3334
username: account.r6950a
Password: password
Device: 0-0 Cayman
Extra Flags: (I put none)
Thread concurrency: 8000
Worksize: 256
Vectors: 1
GPU Threads: 1
Intensity: 18
User Stratum: Yes

I opened the software once for every card with the different username and device.
The r6570 has slightly lower intensity.

6950a @ 900Mhz = 437Khash
6950b @ 940Mhz = 457Khash
6570 @ 725Mhz = 99Khash
5570@ 680Mhz = 77Khash but crashes the computer within 10 seconds... so not running anymore.


That is the issue I am trying to figure out... It worked flawlessly when all cards hashed bitcoins.
If I run it alone, it works.
If I run it with 2 other cards it works.
If all 4 cards run, the PC crashes and I have to reboot it.
I tried having it mine bitcoins alone while the other 3 cards mine litecoins, still crashes.
I tried different intensities, still crashes, lower clock, still crashes.
Could it be ram related ? even if my ram usage is less than 2 gigs ? (according to windows)
Could I play with Thread concurrency ? Lower it for the 6570 and 5570 ?

I am open to suggestions, but all in all, as the hash rate is respectable, I have no issue letting the card sleep, till I pull it and throw it in another machine.

Thank you for your time and the great source of information.

Here is my ultra Guetto miner

[1714048950]

1714048950

[Ilikeham]

with four cards running you are drawing too much power off the PCIe bus and the card crashing is the one that is most sensitive to that... which happens to be one without external power.

4x cards are capable of pulling 300W off the PCIe bus alone, more than you are delivering via the connector to the motherboard. Considering you have two cards that do not rely on PCIe cables but get all their power from the bus, it's too much and something is going to crash.

if you want a fourth card in that computer attach it via a powered riser.

[ummas]

Give it somme more power. connect 2 GPU (6570+5570) into small 350W power suppply and check if it helps.
I hope that You know haw to do it.

Mining BTC drains a bit less power than mining LTC.
700W is not enough - fast count: 6950-200W, 6570-120W?, 5570-100W? MOBO+CPU - 100W

[CoolIT]

Thanks for the help.

I was hoping my issue would not be hardware, but it makes a lot of sense. It's also the first machine I have put so many vga cards on the board.
I know my PSU is very borderline, specially named "AcePower" but then again, I have been using and selling this brand for a multiple years and have pushed them to the limit, have not seen one fail yet.

I will pull the card out and put it on another computer.
I got a core2 with a dual PCIE slot collecting dust + another radeon 6570.
Those cards are nothing special but I might as well put them to good use.

Thanks for the quick replies

Update may2013
The 5570 is still sleeping in the above machine, ill pull it out someday... don't need it for now.
My other Core2 with sli motherboard received 2 radeon 6870's hashing away for litecoins for 312 and 306 Khash


All in all I am happy to reliably gpu hash at 1650Khash for Litecoins, producing about 3 a day.