problem with my hd7950

[asdlolciterquit]

Hi,
i just bought an ATI msi 7950 3gb OC edition, but i'm very disappointed about its hashrate. I red that whit that card i can reach 600 or even more kh/s, but i barely reach 400kh/s, and, most important, i still don't know why!!

My frequency:
gpu clock @880mhz
memory clock @1250mhz
temp @70°

I tried whit:
-different version of cgminer (3.6.2, 3.7.0, 3.7.2), without changes
-different version of catalyst (13.1, 13.9, 13.12), without changes.
-different setting. I tried more or less every setting suggest in https://litecoin.info/Mining_hardware_comparison.
 I noticed that:
 -i can't set intensity greater than 13. With 13 i haven't any hw error, with 14 or more, i have too much hw error.
 -i can't set thread concurrency greater than 8192. If i use greater value i have this error--->
maximum buffer memory device 0 supports says 536870912
your script setting come to 939524096
error -61 etc
failed to init GPU thread 0 disagling device 0

now i'm using this settings --gpu-threads 2 --thread-concurrency 8192 -I 13
                                       setx gpu_use_sync_objects 1
                                       setx gpu_max_alloc_percent 100

any help??

[asdlolciterquit]

up

[bitcointaco]

Your thread concurrency is way too low. Try 25984.

Here is the cgminer.conf which gets all 3 of my 7950s up to 655kh all day long:

{
"pools" : [
    {
        "url" : "stratum+tcp://pool.pool.url:3333",
        "user" : "user",
        "pass" : "password"
    },
    {
        "url" : "stratum+tcp://pool.pool.url:3333",
        "user" : "user",
        "pass" : "password"
    }
]
,
"intensity" : "18,18,18",
"vectors" : "1,1,1",
"worksize" : "256,256,256",
"kernel" : "scrypt,scrypt,scrypt",
"lookup-gap" : "0,0,0",
"thread-concurrency" : "25984,25984,25984",
"shaders" : "0,0,0",
"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",
"api-mcast-port" : "4028",
"api-port" : "4028",
"expiry" : "120",
"gpu-dyninterval" : "7",
"gpu-platform" : "0",
"gpu-threads" : "1",
"hotplug" : "5",
"log" : "5",
"no-pool-disable" : true,
"queue" : "1",
"scan-time" : "30",
"scrypt" : true,
"temp-hysteresis" : "3",
"shares" : "0",
"kernel-path" : "/usr/local/bin"
}

[bitcointaco]

Also, download MSI Afterburner: http://event.msi.com/vga/afterburner/download.htm

Change settings to:

Power Level +20
Core 1152
Memory 1406

(MSI Afterburner works even if your card is not MSI brand)

[asdlolciterquit]

Your thread concurrency is way too low. Try 25984.

Here is the cgminer.conf which gets all 3 of my 7950s up to 655kh all day long:

{
"pools" : [
    {
        "url" : "stratum+tcp://pool.pool.url:3333",
        "user" : "user",
        "pass" : "password"
    },
    {
        "url" : "stratum+tcp://pool.pool.url:3333",
        "user" : "user",
        "pass" : "password"
    }
]
,
"intensity" : "18,18,18",
"vectors" : "1,1,1",
"worksize" : "256,256,256",
"kernel" : "scrypt,scrypt,scrypt",
"lookup-gap" : "0,0,0",
"thread-concurrency" : "25984,25984,25984",
"shaders" : "0,0,0",
"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",
"api-mcast-port" : "4028",
"api-port" : "4028",
"expiry" : "120",
"gpu-dyninterval" : "7",
"gpu-platform" : "0",
"gpu-threads" : "1",
"hotplug" : "5",
"log" : "5",
"no-pool-disable" : true,
"queue" : "1",
"scan-time" : "30",
"scrypt" : true,
"temp-hysteresis" : "3",
"shares" : "0",
"kernel-path" : "/usr/local/bin"
}

There is some problem:
- I can't set intensity greater than 13. With 13 i haven't any hw error, with 14 or more, i have too much hw error.

- I can't set thread concurrency greater than 8192. If i use greater value i have this error--->
maximum buffer memory device 0 supports says 536870912
your script setting come to 939524096
error -61 etc
failed to init GPU thread 0 disagling device 0

one question: that overclock need an overvolt too?

[bitcointaco]

There is some problem:
- I can't set intensity greater than 13. With 13 i haven't any hw error, with 14 or more, i have too much hw error.

- I can't set thread concurrency greater than 8192. If i use greater value i have this error--->
maximum buffer memory device 0 supports says 536870912
your script setting come to 939524096
error -61 etc
failed to init GPU thread 0 disagling device 0

one question: that overclock need an overvolt too?

No, they aren't overvolted except for that powertune setting in MSI Afterburner. They are voltage locked Gigabyte cards.

They are running on the 13.4 win7/8 x64 driver. Maybe flashing the card with another 7950 bios would help if nothing else will work. (there are guides on the forum, don't have the links handy though)

Oh, and they are running cgminer 3.7.2.

[now2ai8]

Try to find your max stable memory clock.  Then find the core clock that is equal the 60% of the max memory clock.   For some reason, this ratio improved my hash rate.  

For example, if your max memory is 1000, then you core clock should be 600.  Hope this makes sense.

[bitcointaco]

                                       setx gpu_max_alloc_percent 100

any help??

You only need to enter that command once at the command prompt. It doesn't need to be a command in a .bat file that is run every time. It will say:

Code:

Success: specified value was saved.

If it works correctly, and that's it, no need for that command again.

Also, have you tried it with the above MSI Afterburner settings?

[Atrides]

now i'm using this settings --gpu-threads 2 --thread-concurrency 8192 -I 13
                                       setx gpu_use_sync_objects 1
                                       setx gpu_max_alloc_percent 100

any help??

For 7950 you must set --gpu-threads 1

[asdlolciterquit]

now i'm using this settings --gpu-threads 2 --thread-concurrency 8192 -I 13
                                       setx gpu_use_sync_objects 1
                                       setx gpu_max_alloc_percent 100

any help??

For 7950 you must set --gpu-threads 1

if i set --gpu-threads 1 --thread-concurrency 8192 -I 13 my hashrate decrease
also, if i try to use highter value of I with  --gpu-threads 1 i have the same problem with too much hw error.

tomorrow i'll try some oc of my videocard with msi afterburn and i'll let you know...


@bitcointaco: flash the card with another 7950 bios...uhm...i'm not sure i'm able to do it.

[Bfljosh]

thread 21712
vectors 1
gpu threads 1
worksize 256

Intensity 19

MSI afterburner settings:

clock 1080 fan 80% memory 1250

Download sapphire trixx to disable ulps settings.

Thank me later.

[LiteMine]

640 kh/s with pretty basic settings,  how much RAM are you running?

-w 256 -g 1 --thread-concurrency 14336 --intensity 19 --auto-fan --auto-gpu --gpu-engine 1100 --gpu-memclock 1250 --gpu-powertune 20

Catalyst 13.1
SDK 2.7
cgminer 3.3.1

[asdlolciterquit]

if i use I = 19 i have 600 or more kh/s, but i also have 100% hw error!!

[iqacid]

im using this config for my 7950 sapphire and i got average 670-675 from that if u have enough cooling i suggest to use 20 for intensity. if not you can get average above 600 with  intensity 17



setx GPU_MAX_ALLOC_PERCENT 100
setx GPU_USE_SYNC_OBJECTS 1
cgminer --scrypt -w 256 --shaders 0 --intensity 20 -v 1 -g 1 --lookup-gap 2 --thread-concurrency 21712 --gpu-engine 1100 --gpu-memclock 1500 --gpu-memdiff 0 --gpu-powertune 20 --temp-cutoff 90 -o "your pool adress" -u "user" -p "password"

[asdlolciterquit]

how can i say that max intensity i can set is 13? i know is low, but even with 14 i have too much hw error!!!

anyone can tell me why?

[st4nl3y]

I would say your thread concurrency and intensity needs tweaking. You have to keep trying different values until you find the best hash and no HW errors and you also need at least 3gb ram to be safe. (you can still run 1,2 or even 3 cards on 2gb but with lower hash rate)

[Wilhelm]

how can i say that max intensity i can set is 13? i know is low, but even with 14 i have too much hw error!!!

anyone can tell me why?

Ok first of all put in your shaders value. Look up the amount of shaders that your card supports and add it to your config.


I had hardware errors on my cards (5850 and 5870).
On some forum they said that increasing thread-concurreny could solve it.

I found a specific thread concurrency value that allowed me to go >I=13 without hardware errors.
With value 5824 I got HW errors but at 6144 none.

So my tip is to look up the thread concurrency value that works best.
Try values and look at the amount of HW errors per minute or per 10 minutes and look if upping or lowering the value helps.

Hope you find the golden ratio.

After you do find the perfect value try lowering the voltage to save power and try to overclock.

[darksoft]

Put this into a command prompt EXACTLY as shown, proper captilization and everything:

setx GPU_MAX_ALLOC_PERCENT 100

And then hit enter. You can't do lowercase. This will solve the hw errors.

[asdlolciterquit]

first of all, thanks for your help

@darksoft: sadly, nothing change

@st4nl3y: i have 4gb dd2 1066mhz

@Wilhelm:

i tried different value of thread-concurreny. Value greater than 8192 causes hw error, and values lower than 8192 causes hw error

Where can i find my shaders value? i found this link http://www.game-debate.com/gpu/index.php?gid=1588&gid2=890&compare=radeon-hd-7950-sapphire-3gb-boost-edition-vs-geforce-gt-640-144-shaders. 1164.8 is correct? how can i put it in cgminer string?

i knew that if i overclock my video card, i need to overvolt, not to undervolt...are you sure is safe?

[P1tBull]

Have you downloaded AMD App SDK ? Which version ?