cgminer, 7950 and scrypt

[Thracian]

Hi!

I'm trying to test Litecoin mining using a SAPPHIRE 7950 3GB, but I'm getting no more than 410 kh/s instead of expected 600 kh/s

Intensity >16 leads to unstable system crashing
thread-concurrency > 8192 is not working
gpu and mem speeds can go higher but don't increase hashrate
I've tried --shaders 1792, nothing spectacular happened.
OS is win7 64bit, 8GB RAM, CPU i5-2310@2.9Ghz, GPU temp around 63 Celcius

Here's the batch I run:

setx GPU_MAX_ALLOC_PERCENT 100
setx GPU_USE_SYNC_OBJECTS 1
cgminer -o http://POOL:PORT -u USER -p PASS --scrypt --intensity 15 -g 1 -w 256 --thread-concurrency 8192 --gpu-engine 1000 --gpu-memclock 1350

Any suggestions? Can you post your working settings and speeds?

Thanks!

Update 1
NEW WORKING SETTINGS, still at 400 Kh/s
--scrypt --intensity 18 -g 1 -w 256 --thread-concurrency 21712 --gpu-engine 1100 --gpu-memclock 1600 --gpu-powertune 20 --lookup-gap 2


Update 2 (see below)
Better settings for me so far giving 575 kh/s

--scrypt --intensity 13 -g 2 -w 256 --gpu-engine 1095 --gpu-memclock 1475 --gpu-powertune 20 --lookup-gap 2

[1715485964]

1715485964

[zif33rs]

powertune to 20?

[Thracian]

Yes, thanks, I forgot it, now at least I have new working settings, no crashes, but still 400 kh/s even at 1600 Mhz!

NEW WORKING SETTINGS
--scrypt --intensity 18 -g 1 -w 256 --thread-concurrency 21712 --gpu-engine 1100 --gpu-memclock 1600 --gpu-powertune 20 --lookup-gap 2

powertune to 20?

[zif33rs]

start over. go into cgminer and delete all the .bin files.  just the .bins   Then go and delete everything in your config file.  restart your comp.. reenter cgminer with just --scrypt and your server settings.  let it run for abit if it starts. once its up and running set powertune to 20....save the config and exit.  open up cgminer file...look for the newly genetated .bin file.  Note the number of your thread concurrency. exit and reboot. 

setx GPU_MAX_ALLOC_PERCENT 100
setx GPU_USE_SYNC_OBJECTS 1
cgminer --scrypt -o (your server) -u (your username) -p (your password) --thread-concurrency (your number from the .bin) -I 13(start here,raise once everything is stable till crash,lower) -g 2 -w 256



I have noticed that cgminer will have different hash rates with all the same settings. sometimes I have to stop and restart it a couple of times for the settings to "stick" 

good luck

zif

[zif33rs]

Try setting your gpu engine to 1200mhz. For what ever reason my system runs better with concurrency set to 8192 and intesity 13...I loose alot of hashrate trying to raise these. I am still getting over 600khs per card tho.
You are just going to have to play around with these settings till you find a sweet spot. Every card seems to have diff setting for optimal.
good luck

zif

[Thracian]

Thank you very much! I'll try these, in the next few days.
For now back to bitMinter, mining BitCoins!

Try setting your gpu engine to 1200mhz. For what ever reason my system runs better with concurrency set to 8192 and intesity 13...I loose alot of hashrate trying to raise these. I am still getting over 600khs per card tho.
You are just going to have to play around with these settings till you find a sweet spot. Every card seems to have diff setting for optimal.
good luck

zif

[Thracian]

Nothing worked

All the settings you proposed and going from fresh install to beta drivers, and trying every value I could imagine.
Always got 350-400 Kh/s

I think I'll just have to continue on bitcoins, until DrHaribo ads litecoins to BitMinter

Thanks anyway!

Try setting your gpu engine to 1200mhz. For what ever reason my system runs better with concurrency set to 8192 and intesity 13...I loose alot of hashrate trying to raise these. I am still getting over 600khs per card tho.
You are just going to have to play around with these settings till you find a sweet spot. Every card seems to have diff setting for optimal.
good luck

zif

[beppe]

I think you should set intensity to 9: the cgminer readme says that values >10 are not for existing hardware (whatever it means)

[TheSpiral]

Strangely, I get my best hashing done on Intensity 12. Toy around with the intensity levels, even if they seem too low on paper, there's usually a sweet spot.

[mxmz.in]

I'm running 3x7950 averaging over 1550 kH total with this config (stable):

"intensity" : "20,20,20",
"vectors" : "1,1,1",
"worksize" : "256,256,256",
"kernel" : "scrypt,scrypt,scrypt",
"lookup-gap" : "2,2,2",
"thread-concurrency" : "24000,24000,24000",
"shaders" : "1792,1792,1792",
"gpu-engine" : "0-0,0-0,0-0",
"gpu-fan" : "0-85,0-85,0-85",
"gpu-memclock" : "0,0,0",
"gpu-memdiff" : "0,0,0",
"gpu-powertune" : "0,0,0",
"gpu-vddc" : "0.000,0.000,0.000",
"temp-cutoff" : "95,95,95",
"temp-overheat" : "85,85,85",
"temp-target" : "75,75,75",

power +20, doing more OC allows to go over 1800 but I don't want it now due to heat/noise/possible instability

[Thracian]

Could you please post your GPU & mem speeds?

I'm running 3x7950 averaging over 1550 kH total with this config (stable):

power +20, doing more OC allows to go over 1800 but I don't want it now due to heat/noise/possible instability

[inspireweb.ro]

I get ~595Kh/s with this settings
cgminer --scrypt -o stratum+tcp://poll-adress -u user -p pass --intensity 13 --gpu-threads 2 --worksize 256 --vectors 2 --shaders 1792 --thread-concurrency 12188

and the clocks :
gpu: 1135Mhz
mem: 1495Mhz
Powerlimit : 20%
Core Voltage : 1.181v
Fan speed locked at 45%, never pass more then 70C. Now with 27.1C in my room , the video card has 65C .
I have an SAPPHIRE HD 7970 3GB GDDR5 OC with Boost .

If anyone with hd7950 has better settings please post it here.

[Thracian]

Here's what finally worked, at 575 kh/s with very stable system
(I went up to 600+ with more mem Mhz and engine Mhz, but it kept rebooting after a few minutes).
Although set to 1.25 the actual voltage reported is 1.106

The most important part I think was "gpu-threads" : "2"
For some reason 1 thread, or more than 2 threads lead to much lower performance.

THANK YOU FOR YOUR HELP!


"intensity" : "13",
"vectors" : "1",
"worksize" : "256",
"kernel" : "scrypt",
"lookup-gap" : "2",
"thread-concurrency" : "0",
"shaders" : "1792",
"gpu-engine" : "0-1095",
"gpu-fan" : "0-100",
"gpu-memclock" : "1475",
"gpu-memdiff" : "0",
"gpu-powertune" : "20",
"gpu-vddc" : "1.250",
"temp-cutoff" : "90",
"temp-overheat" : "85",
"temp-target" : "75",
"expiry" : "120",
"gpu-dyninterval" : "7",
"gpu-threads" : "2",
"queue" : "1",
"scan-time" : "30",
"scrypt" : true,

[some values deleted]

[Thracian]

Unfortunately these settings made my system reboot in less than 1 minute.
Intensity >13 is NOT for my system.

But there's also a nice conclusion from them:

By using one thread, you can have "thread-concurrency" of 24000.
Using two threads, you should have smaller "thread-concurrency" (my "auto" by cgminer is 8960 for some reason)

Try my settings for sapphires:
You should be getting 595-605 with the above.  600+ if you change intensity to 20.

[Thracian]

Yeap, PSU is 850w for just one 7950 and
Board power at trixx is +20% reporting VDDC 54w at 1095/1475

Look at PSU. Are you providing enough juice?
BTW, one thread and tc of 24000 is more stable than two threads...

[bustaballs]

Thanks for the replies in this thread. I bumped by 7950s from barely 500kh/s to around 550kh/s by playing around with some of the values mentioned here.

[ma_rine_sa]

i would like to add that i am having this issue too so it is not just the OP...

I have spent over 24 hours smashing my head against the wall trying to figure out why my sapphire 7950 4L simply will not mine, can not connect to servers, produce HW errors.

turns out i require 2 gpu threads to mine. 1 gpu thread will not connect me on to any server! i've been searching this issue and there are some people with this issue.

do note that i have 5870 and 5970 mining at 400 hash per core  and soon as i put a 7950 on to that machine h/w are produced!

i am thinking maybe it is either the brand new 5 * sapphire 7950 4L cards that have this issue or it is the operating system. hoping to get windows 8 installed and see what results i get.

current using server 2008 r2 and just like the OP too auto thread-concurrency give me 8960

[FredDag]

I have spent over 24 hours smashing my head against the wall trying to figure out why my sapphire 7950 4L simply will not mine, can not connect to servers, produce HW errors.

Same boat here, except it looks like i'm finally getting to a setup that's mining alright. Maybe not perfect, but a lot better than what I was getting.

FYI, here's details of my setup as it was yesterday & now.
I hope someone finds it useful.

FD


2 x 7950 Frozrs - No Crossfire
Win7 64 w/ cgminer 3.1
AMD SDK 2.7
Catalyst 13.4

Yesterday
- AMD 2.8 SDK
- using (very basic - pool authentication only) .bat with cgminer
- anything over intensity 12 produced HW errors. -I 20 literally produced 100s of them in minutes
- Utility rate of about 3 shares a minute
- GPU Temps 80C with fans @ 85%

Today
1. Removed the AMD 2.8, the cgminer readme mentions known issues with this, and installed AMD SDK 2.7.
2. Removed the .BINN files from the cgminer folder, started it using cgminer.exe and entered pool info. The new .BINN file created contains a thread concurrency value, record that. In cgminer use menu then [W] which created a cgminer.conf file.
3. Edited the new cgminer.conf with details... adding a couple then testing, then repeating.
4. Set memory & GPU clock speeds following this guide. https://bitcointalk.org/index.php?topic=175646.0
   
Things I noticed
a. Any Intensity over 12 causes HW errors and lower Utility rate. So, -I 12 it is.
b. Any Thread Concurrency over 8000 causes the driver to crash. I'm now using 4032 as it was the value cgminer used in step 2.
c. 1600Mhz was  stable with 1100Kh/s, but the Utility rate was very low at around 6-7 Shares/m.
--- Setting 1450Mhz dropped the hash rate to 920Kh/s, but the Utility rate rose to around 30 shares/m.
--- Sweet spot for this GPU Clock seems to be 0.672 * Memory Clock. So 974Mhz, this gets me 920kh/s with almost 0 HW errors.
d. GPU Temps now 65C with fans @ 55%

Config:
"thread-concurrency" : "4032,4032"
"lookup-gap"      : "1,1"
"intensity"      : "12,12"
"vectors"         : "1,1"
"worksize"         : "256,256"
"kernel"             : "scrypt,scrypt"
"scrypt"            : true
"shaders"          : "1792,1792"
"temp-overheat" : "85,85"
"temp-cutoff"  : "90,90"
"temp-target"  : "75,75"
"gpu-powertune" :  "20,20"
"gpu-fan"        : "auto,auto"
"gpu-platform" : "0"
"gpu-threads"  : "2"

// Used for CGWatcher
"api-port"        : "4028"
"api-listen"     : true
"api-allow"     : "W:127.0.0.1"

[Sparkzor]

Mem clock does nothing on AMD. I get 500kH/s with 1050/1000 on my 7950, Intensity 15.

[sirstiv]

setx GPU_MAX_ALLOC_PERCENT 90  <--- my recommendation for rigs that have annoying stutters
setx GPU_USE_SYNC_OBJECTS 1