Bitcoin Forum

Hallelujah I have solved it.


If you have a radeon several 7950 or 7950 cards and can not raise intensity past 13 or gpu threads past 8000/8192 without getting HW error or crashes, the problem is caused by a lack of RAM. I had the same problem on my 3 GPU rig and no matter what I did I could not fix it. Once I upgraded from 2GB to 6GB of RAM everything worked perfectly and I could raise the intensity past 13 and the threads to 21k+.

That's interesting.  I'm struggling with this problem now with a 2x 7950 rig.  Even Intensity 13 is giving me some errors.

I have 4Gig RAM, so maybe I'll pick up 4 more... 

Can you post if you notice you are getting errors again.

Thanks,
 

Are you using Reaper or CGMiner? I have two rigs with 3x7970s and they work fine with 4GB of ram at an intensity of 20. Cgminer, Win 7.

I'll try it in a minute. 32GB of DDR2400 should be pretty definitive.

I was using cgminer. 4GB may work as well. Initially I had only 2 Gb and was getting all the problems. Then I stuck in more ram and everything now works correctly.

I made a change to my first post I had 2 and then added 4 more for total of 6.

Not getting any errors. Everything is working now. I got 2 rigs with 3 7950 and the both hashing away nicely. Both pool and local hash are pretty close, lots of submitted shares. so i know its working properly.

I had the exact problem with my 7950/70 while I was mining LTC
instead of adding memory I just switch back to BTC :D

If it helped great, but I don't see how it could. CGMiner is only using 0.0448227 GB of RAM right now on my desktop computer.

4GB should be a good starting point one of mine has 4GB the other 32GB (its my VM server and supports 512GB!)

That's what I thought too, but apparently that is not the case. It seems to need the memory to be there.

I had the same symptoms with my system, to many hardware errors.

The system had 2GB RAM so after reading multiple posts I decided to buy another RAM module 4GB this time and installed it. 6GB total.

Same thing! Hardware errors all over the place >:(

Then I took out the old module (2 GB) and no more hardware errors  :D

Turns out it was not the quantity it was the quality  ;D

I have 2x7970,
with 32GB memory i still cant get over intensity 13.. going to intensity 14 chops my hashrate from 580 to 420...
this also aspire to my other rig with 1x7970 and 4x7850

Wonder how people are able to get beyond I13 on amd7xxx series...
All other rigs i have is tweaked intensity on (4x5870,3x6870,2x6970) works like a charm with intensity 16

That much memory is definitely overkill unless you want to do something else with that computer like run a database... Going beyond what is functionally the minimum required to run the OS + mining operation is not going to add any benefit to your operation.

580kh/s sounds about right for a 7970 at I13, though.

You will get HW errors when using cgminer intensity over 13 on the 79xx unless you set the thread-concurrency high enough to prevent worker threads from overwriting each other's memory space when operating at higher intensities. This might not improve your kh/s at all, but you can try setting your thread concurrency for the 7970 to 20480. If you get a cgminer error when starting it with that setting, it means you need to set the GPU_MAX_ALLOC_PERCENT environment variable to 100. You can do that by executing this command (only one time is necessary - don't add to batch file that starts miner)

setx GPU_MAX_ALLOC_PERCENT 100

(case-sensitive, so make sure it's all caps)

use GPU_MAX_ALLOC_PERCENT 100 already. however i dont think ive set threads more then 8xxx something.
If i set shaders to 2048 i get around 20480 threads. will try a bit more.

Found out that if i put the cards at intensity 18-20 i got around 650-700 hash but generate alot of hw error.

Reason for 32gb memory is due to its also my workbench (unity/blender etc).

Before buying new RAM, try changing the page file size: http://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/sysdm_advancd_perform_change_vmpagefile.mspx?mfr=true

Worked for me.

But i get best speeds from using -I 13 -g 2 - 730Kh/s from a sapphire vapor-x ghz 7970, undervolted and underclocked running 60C

Thanks for this topic. I was so much worried about my 7950s which were giving tons and tons HW errors. im using only 2GB of RAM,

now i'll upgrade to 6GB.

Are you getting 730khs from single 7970? or from 2 ?

i was just wondering i have a VTX3D AMD Radeon HD 7870 Tahiti LE. when i mine i get on average 345kh/s.

is that the max i can get without it blowing up.  ???

You guys are in the wrong forum for GPU mining. There is a wealth of information over in the litecoin forums.

Here is a great starting point: https://litecointalk.org/index.php?topic=12369.0

After going through that you should be able to find a modded bios for your card, if not you can upload yours and ask for it to be fixed. All my 7970's (R9 280x) hash at 725Kh, low temps, undervolted at Intensity 13.

hi everyone.

ive been mining with my vtx3d 7870 black tahiti le for a while now and im getting 345kh/s with cgminer i was just wondering if i could get a higher hashrate. this is my command.

--worksize 256 --lookup-gap 2 --thread-concurrency 8192 -g 2 --intensity 12 -Q 0

any help would be great. thanks.

For those of you who were asking if you're getting the normal rates, you can use this chart as a general guide. https://litecoin.info/Mining_hardware_comparison (https://litecoin.info/Mining_hardware_comparison). It's not a definitive guide, and there's a link they call the "raw data" page with a bit more updated information, however it hasn't been filtered or sorted as the 1st link. https://litecoin.info/Mining_hardware_comparison/raw_data (https://litecoin.info/Mining_hardware_comparison/raw_data) is that one. You can look at your model number there though and get a good idea if you're in the ball park or not of where your card is.

My system has 16GB of RAM, and I cannot go past 13

Hello,

i have upgraded my system RAM to 6GB, but the problem of 13 intensity still persists.

before i was using 2GB, later i added 4GB. it system works fine with only 2GB, and also works fine with 2GB + 4GB.

But i have to say that the my monitor display goes black when i use 4GB RAM.

please help.