Topic: Consolidated Litecoin Mining Guide for 5xxx, 6xxx, and 7xxx GPUs - page 10. (Read 624212 times)

So I had all 4 cards running in my case, but with them being all crammed together, it was way too hot.  So I pulled everything out and sat it on a rack.  I have 2 of the cards plugged into the board, a 3rd card plugged in via 16x riser cable, but couldn't get the 4th card to work with another 16x riser cable. So, I ordered a 1x to 16x riser cable and hopefully this will solve my problem.

In the meantime, I'm running 3 cards and getting pretty nice hashrates.  These are my settings and results using cgminer 2.11.3 and AMD Catalyst 13.1 drivers:

--intensity 13 -g 2  715/710 = ~1500Kh/s
--intensity 13 -g 2  925/1000 = ~1950Kh/s
--intensity 13 -g 2  1000/1206 = ~2100Kh/s
--intensity 13 -g 2  1022/1244 = ~2150Kh/s

Other settings:
--thread-concurrency 8192 -w 256

I've literally spent most of a entire week playing around with settings and trying to find the sweet spot and I feel like I'm pretty much there.  As you can see, I actually underclocked my cards to get these hashrates.  Stock clocks are 1100 core/1500 memory.  Unfortunately the default voltage is about 1.2 volts on my cards and its locked (@#&($$^(@&$!!), otherwise, I'd be able to save 100-150W easily by undervolting.

https://i.imgur.com/rzwfhgI.png

I'm seriously thinking about getting rid of these cards and getting 7950s or 7970s that don't have the voltage locked.  Having the voltage locked is such a huge drawback, I'm just wasting too much power right now.

Looking for help to improve kH/s/W.

Here's my setup:
MSI Z68MA-ED55 (B3) motherboard
Intel G530 processor
4GB DDR3 1066 RAM
7950 Sapphire 100352-2L (purchased March 2013, voltage unlocked!)
16X-16X riser cable
Corsair TX750W power supply
AMD 13.1 drivers
AMD SDK 2.8
cgminer 2.11.3 (-I 20, --tc 22400 -w 256 -g 1 -l 1)
Sapphire Trixx

Best settings: 925/1250/.962V 560kH/s 3.29 kH/s/W.

Given high electricity cost my goal is to maximize kH/s/W.

My current best setup is 925/1250 at 0.962V for 560 kH/s at 170W or 3.29 kH/s/W, after many hours of systematically mapping gpu clock (850-1250), memclock (1250-1750), and gpu v (0.900-1.250). I've had the rig up to 740 kH/s stable (1225/1750/1.250V) but at 345W or 2.14 kH/s/W the efficiency just isn't there (would be great for a free power situation!).

Looking for advice from the experts on what to do next to improve my efficiency.

Thanks,

Tejsei

whats the best GPU i can actually buy right now for BTC or LTC mining?

i found ATI Radion 5870s for sale online but they were for Mac.

i'm not looking to make money, i just want to mine BTC/LTC.

the newer revision of the gigabyte card is voltage locked.

i dont believe that the sapphire dual-x cards are locked

I'm running HD 7950 and 7770.
Here's the command line for cgminer that I pass it:
cgminer.exe --scrypt -o stratum+tcp://site -u username -p pass --shaders 1792,640 -w 256,256 -v 1 --intensity 18,14 -g 1 --thread-concurrency 21712,8000 --lookup-gap 2,2
and I get an error for the hd7950 device:
Error -5: Enqueueing kernel onto command queue. (clEnqueueNDRangeKernel)
Is there any way to fix this? It seems that no program accepts high values for thread concurency for me although I already set a global value for GPU_MAX_ALLOC_PERCENT 100
I also seem to get a lot of HW errors for 7950. I have catalyst 13.3 and app-sdk 2.7 installed.

This Litecoin mining is less a Science at this point than it seems to be Sorcery.

I had to completely and radically change the cgminer settings to get the same performance from this card on a riser in the 3rd slot. 

Why on earth would two identical cards require wildly different settings in different slots on the same motherboard but in the end perform the same?  I think there is a LOT better performance that could be had from GPUs in scrypt mining - this inconsistency shows unoptimized and possibly buggy software imho. (at least on RADEON 79XX).

I'm using GUIminer scrypt to mine with CGminer and I just got a 7950. On 5000 series cards GPU usage was always steady while mining but my 7950 jumps up and down all the time. Any idea what could be causing this? The big drop is me stopping mining for a few seconds. It jumps from around 64% up to 99% and back.

already ordered the 7970=P
Still have 2x pci-e16 slots over, so might go for those in the future.
Btw, are ALL of those cards voltage locked? Or just the newer editions? And what temperature are your cards at when mining?
Even if i manage to burn it out after a while, 2 year waranty should help, no?

Check if the riser is seated correctly.

I had an issue with one card showing erratic behavior (sometimes not detected on reboot, "DEAD" in cgminer at stock settings, overall lower hash rates than the other identical cards on risers) until I firmly reseated the riser.

Can anyone comment on using PCI-E risers?

I just implemented a third card on a rig using a riser - and the card in the third slot that is on the riser is only getting like 350k/H - where the other 7950 in directly in slots 1/2 are getting 550k/H.

Can riser lower hashrate that much?  Also the card with the riser won't let me set fan speed in cgminer?