Topic: Optimizing ATI performance, 6950 in particular - page 4. (Read 52510 times)

Some say you get better performance mining in linux versus windows.  I can't vouch for that claim myself.  The biggest problem I've had for mining in linux (beyond learning how to use linux itself) is overclocking in linux.  AMDoverclockctrl seems to be the way to go as far as overclocking in linux goes.  However, 6950s are limited to 840mhz for the core through the bios.  As far as I know, there is no way around this for software in linux.  Windows has several programs that will allow you to bypass the bios limit.
It looks as though a bios modification program called RBE for windows has some options that I am looking into myself.  It looks like there might be possibility, but I am not sure if it's really worth the hassle and risk of reflashing with a bios I modified myself.
If any of you look into RBE bios modification in terms of the increasing the overdrive limit and such, be sure to open RBE and read the warning concerning 'method 2 - no hash'.

There is a 'clock settings' tab on RBE, but I am not sure if you can go over the limit with just that alone.  It looks promising, but there is risk involved and I have too much uncertainty concerning the idea.

technically you can flash in windows, but dont, there's just way more chance of it not working or you locking up / bricking your card. its happened regularly to someone i know. but the dos way is trouble free

repeat, if you arent willing to do it in dos dont do it
technically it prob will void your warranty, but whether it eventually stops you getting a replacement or money back is in the hands of the gods

did you work out if its a non-reference board or not ?

Can the flashing happen within windows?As I am rubbish with cmds and other high risk ops at boot time.is there a utility thats all windows based?Will modding this card void my warranty?

sorry but there aint much gain to be had with just miner parameters, your pretty safe oc'ing just your core mhz to something stable. voltage and heat are the real killers so watch out for them. under 90c is ok but around 70 is better.


-f60 for example will affect miner priority and will help with sluggishness , but lockups while using other programs that access the gpu wont be stopped by this. that is a bug that is being fixed in next ati release apparently. though you can try a different miner in the mean time.


this is  a paradox, as lower temperatures = more noise , and vise versa. you can try finding a happy medium by manually fixing the fan speed to meet your likes, or trying to increase case airflow.


has it got all the crazy black plastic shroud ? does it have dual bios switch ?with fan in half way along board ? or is it like most stock cards with fan at rear of board ?
stock reference = better for flashing but you should be ok either way to try unlocking shaders



backup bios with gpuz
open bios in rbe (radeon bios editor) in extras? enable 6970 shaders option, save as
create boot usb/floppy/cd/whatever
flash with atiflash command line tool off boot dos (not windows)

atiflash -p 0 card.rom
(assuming you have 1 card installed)

if shader count has gone up in gpuz it worked.

What flags can I use in GUIminer that can :
a.boost my performance (as I only get 290MHash/s stock speeds as Im afraid of burning out my card by OC'ing,or flashing HD6970 BIO which I don't wanna do)
b.Allow me to use other apps without freezing my PC
c.Keep temperatures and noice under control as that fan is very load at 60% and above.

It's a Sapphire board,(has AMD logo on PCI-E connector and bought it on 29/06/2011 so I don't know if it's even unlockable but was on sale)

Also I need clear steps on how to just unlock shaders without moding into HD 6970.

Thank you

ive the GA 6950 OC

i used to get 330 with it just OC'd @ 895mhz

but i just got it unlocked simply though this may not work in all cases.

getting 360Mhs now.

backup bios with gpuz

mod with rbe to unlock shaders

reflash off boot disk (not windows important) with atiflash

Almost sure that model can not be unlocked, actually most of the current models can not be unlocked, look for models that are a clon of the reference design and/or with an AMD logo on the PCI connector.

Does anyone know why Afterburner can't change memory frequency for my cards? When I try to underclock them afterburner graphs still shows 1250.
I have 3GPU in my system. Then I tried to use Ati Tray Tools. But it doesn't allow me to choose adaper to overclock/underclock. If I check "Apply to both adapters/cores" then it applys to GPU1 and GPU3 and Afterburner shows memory frequency change on graphs. But it doesn't affect GPU2.
Any ideas why afterburner works wrong? I'm using latest x64 driver v7.14.10.08.33 on my Win7.

Memory quantity is not important for mining but some 1GB cards are not unlockable, so beware.

I bought a sapphire 1GB to spare some bucks and the bios is in rom, unflashable

Are these any good:

http://www.newegg.com/Product/Product.aspx?Item=N82E16814150523&cm_re=6950-_-14-150-523-_-Product

I wasn't sure if the 1GB model could be unlocked. Does 1GB vs 2GB for mining matter?

It seems this card is out of stock: http://www.newegg.com/Product/Product.aspx?Item=N82E16814127555&Tpk=MSI%20R6950-2PM2D2GD5%20Radeon%20HD%206950%202GB

What's a good 6950 card for me to pick up that can still have the shaders unlocked? I don't care about the 6970 BIOS - just want to unlock the shaders for a higher hash rate. Looking to pick up 2 for my desktop rig.

ok i just added another reference 6950 and unlocked it..now i CANT get them both to run without crossfire disabled..YES im using a dummy plug...

right when i plug it in and plug in the monitor, all thats displayed is the centre portion of my desktop wallpaper...SO frustrating..

did manage to get it working once..was mining on one card and playing crysis 2 on the other..how the hell do i do that again:s help guys

Thank you for all the useful info, I was able to overclock my 9650 unlocked to 930Mhz core using MSI afterburner but for a number of reasons I would like to run it under linux.

So, does anyone knows how to override the 840Mhz limit under linux using aticonfig or similar software?

TIA,
Dusty

I noticed 300-400 memory range gave huge amount of more heat than 760.

Try mimicking my settings.

My setup:
MSI R6950-2PM2D2GD5 Radeon HD 6950 2GB
Mountain Mods Bob Slay v2 (with no case fans  )

My settings:
1.175 voltage / 950 core / 450 memory / 60 fan / 408 Mhash/s
guiminer / poclbm / -v -r5 -f0 -w128

Notes
Temps around 67-71.
I have pushed it to higher voltages but I'm not certain that it helps.
The main factor seems to be core clock.
I can push the core to 965 pretty stable, but it's a small difference in Mhash/s so sometimes I don't bother and just do 950. I'll test this more soon.
450 seems to be a wall for how low I can set the memory. 425 causes artifacts. Not sure if something else ties into this.
If I have to use the PC for something, I stop the miner, change the f flag to -f60, and start it again.

Have unlocked shaders and OC up to 925/300. Voltage is 1.1 and peak temp was 80 C. 365 Mh/s with -v -w128 -f 2
 Think might actually push it further

I am in the same boat... I can push 350MH/s with overclocking but haven't been too stable at that level so I run just a bit of overclock and get ~330MH/s.  Somehow I managed to randomly get a model that can't (yet) be unlocked.  I read the thread you started and will follow it.

It may be worth noting some 6950s cannot be unlocked because the flash is hardware locked so although one can easily make a proper rom one cannot flash it, for example XFX 6950s hardware revision A.3 (current Newegg offering) cannot be flashed. With that said techpowerup is one of the best sites to go for information and I have a thread going over there on a physical hardware hack, not sure if it will work yet but I'm playing with it.

Thanks. I've tried this and I'm getting 332Mhash/s when running these. It's stable just isn't fast.

I'm using these cards http://www.newegg.com/Product/Product.aspx?Item=N82E16814127555&cm_re=6950-_-14-127-555-_-Product

I unlocked using OPs instructions, GPU-Z is showing shaders at 1536 unified. 

Any other ideas on this?

Does anyone have experience OC'ing Powercolor 6950's 1GB cards with the BIOS switch? 

I can get them to run 360 Mhash or so with one card but with four am only getting about 300 each (they are well spaced with risers and not running too hot). 

Specifically, looking to see if I can do all the OC'ing and settings in the windows tools and then bring the cards back over to linux boxes.  Will this work?