Author

Topic: Why do my 7970s only get 675 Mh/s? (Read 2476 times)

sr. member
Activity: 433
Merit: 250
April 16, 2013, 10:42:38 PM
#18
you guys seem to know a lot about 7970's

any idea with this problem?


I have a computer with 2 cards in it. A 7970 and a 6950.

I am running GUI Miner CG Miner lite coin edit and am mining litecoins from a pool.

Heres the problem, when I run and mine on both I get the results

7970: 600+ hashes
6950: 400+ hashes

The problem is for the 7970 the shares are not being accepted on the pool while the 6950 is just fine.

I found one solution was to change the GPU Thread from 1 to 2 for the 7970. Shares started being accepted but another problem occured.
The 7970 started running between 200-400 hashes.

Any ideas or help greatly appreciated.
legendary
Activity: 952
Merit: 1000
April 11, 2013, 03:36:15 PM
#17
You're a dirty bird Mr. 8s
Only the dirtiest for you.  Wink
DrG
legendary
Activity: 2086
Merit: 1035
April 11, 2013, 12:02:22 AM
#16
C8's advice is spot-on in my opinion, and I'm actually giving his exact settings above a shot on one of my machines to see what happens too.  That and my <60 posts vs his 3,000 should probably speak for themselves.  Smiley
Ya hopefully it works great for ya. Post count is somewhat irrelevant, but I just like to regurgitate information. Tongue  Wink

You're a dirty bird Mr. 8s
legendary
Activity: 952
Merit: 1000
April 10, 2013, 11:00:17 PM
#15
C8's advice is spot-on in my opinion, and I'm actually giving his exact settings above a shot on one of my machines to see what happens too.  That and my <60 posts vs his 3,000 should probably speak for themselves.  Smiley
Ya hopefully it works great for ya. Post count is somewhat irrelevant, but I just like to regurgitate information. Tongue  Wink
sr. member
Activity: 389
Merit: 250
April 10, 2013, 10:07:35 PM
#14
I'm managing just under 40 x 7970s and the 675 Mhash you are seeing is in line with what I have seen pretty consistently too.  You may be able to squeeze out a few more MHash/sec by upping voltages a bit (and probably increasing instability or card lifetime too), or by using some alternate cooling method like water-cooling, that is probably not worth the cost at this point the game.

C8's advice is spot-on in my opinion, and I'm actually giving his exact settings above a shot on one of my machines to see what happens too.  That and my <60 posts vs his 3,000 should probably speak for themselves.  Smiley
legendary
Activity: 952
Merit: 1000
April 10, 2013, 09:57:03 PM
#13
Are my drivers correct?
I use 13.1. I'm not a fan of mining on beta drivers, but they should work just fine.
M3t
newbie
Activity: 42
Merit: 0
April 10, 2013, 07:52:05 PM
#12
Are my drivers correct?
legendary
Activity: 952
Merit: 1000
April 09, 2013, 11:42:08 PM
#11
A lower intensity can actually decrease hashing? Sad
Yes. Setting an intensity too low can decrease the load on the GPU, and you will not be performing at maximum potential. Too high of an intensity, and things get mashed, and your performance again takes a hit. That's why I said to stick with an I of 7.
hero member
Activity: 826
Merit: 500
April 09, 2013, 08:11:53 PM
#10
Just want to chime in I have two 7970

One is a XFX that gets 600ish @1100 @82-84C at max fan

The other is a powercolor watercooled that I havent tuned 100%
Its getting 730 @1200 @45C Smiley

M3t
newbie
Activity: 42
Merit: 0
April 09, 2013, 07:19:44 PM
#9
A lower intensity can actually decrease hashing? Sad
legendary
Activity: 952
Merit: 1000
April 09, 2013, 07:15:21 PM
#8
And I have dual 7970s (obviously). They both go at 675 Mh/s at 73 degrees Sad

Help!!

These are my parameters for CGminer: -I 16,16 --gpu-powertune 20 --gpu-engine 1125 --gpu-fan 100 --temp-overheat 82

How do I overvolt/undervolt and what is the advantage to doing that?

675MH/s sounds about perfect for 1125MHz. What makes you think they should be getting 800?

Try changing your parameters to this:
Code:
-I 7,7 --gpu-powertune 20 --auto-gpu --auto-fan --gpu-engine 800-1125 --gpu-fan 40-100 --temp-target 70 --temp-overheat 82 --gpu-memdiff -150
Would you please care to explain how a lower intensity and variable gpu engine would help my hash rate? Also, I really like fans going at 100 all the time Smiley Makes me feel in control.
Those auto tuning options are designed to constantly keep your temps at 70C. If the card starts getting too warm, it will increase the fan speed. If the fan is at max and it's still too hot, it will start downclocking the core to a lower speed. Between these two options, you will never overheat your GPU.

For intensity, there is no benefit to going higher than 7. If you go too high, you can actually lower your hashrate. There is actually very little difference between 6 and 7, but almost no difference between 7 and 8 or 9.

The biggest addition is also the last option, "--gpu-memdiff -150" This will keep your memory speeds 150MHz lower than your GPU core engine speeds, which is the lowest that CGMiner can set them to. This will help with power consumption and lower temps compared to stock speeds.
M3t
newbie
Activity: 42
Merit: 0
April 09, 2013, 06:40:29 PM
#7
And I have dual 7970s (obviously). They both go at 675 Mh/s at 73 degrees Sad

Help!!

These are my parameters for CGminer: -I 16,16 --gpu-powertune 20 --gpu-engine 1125 --gpu-fan 100 --temp-overheat 82

How do I overvolt/undervolt and what is the advantage to doing that?

675MH/s sounds about perfect for 1125MHz. What makes you think they should be getting 800?

Try changing your parameters to this:
Code:
-I 7,7 --gpu-powertune 20 --auto-gpu --auto-fan --gpu-engine 800-1125 --gpu-fan 40-100 --temp-target 70 --temp-overheat 82 --gpu-memdiff -150

Would you please care to explain how a lower intensity and variable gpu engine would help my hash rate? Also, I really like fans going at 100 all the time Smiley Makes me feel in control.
member
Activity: 117
Merit: 10
April 09, 2013, 06:06:10 PM
#6
I have two 7970's, and one gets about 680 and the other 660.
legendary
Activity: 952
Merit: 1000
April 09, 2013, 05:37:16 PM
#5
And I have dual 7970s (obviously). They both go at 675 Mh/s at 73 degrees Sad

Help!!

These are my parameters for CGminer: -I 16,16 --gpu-powertune 20 --gpu-engine 1125 --gpu-fan 100 --temp-overheat 82

How do I overvolt/undervolt and what is the advantage to doing that?

675MH/s sounds about perfect for 1125MHz. What makes you think they should be getting 800?

Try changing your parameters to this:
Code:
-I 7,7 --gpu-powertune 20 --auto-gpu --auto-fan --gpu-engine 800-1125 --gpu-fan 40-100 --temp-target 70 --temp-overheat 82 --gpu-memdiff -150
M3t
newbie
Activity: 42
Merit: 0
April 09, 2013, 04:41:03 PM
#4
Should I be using the 13.3 beta drivers or revert to 13.1?

Does it matter?

Is the SDK compatible with only catalyst 12.1?
member
Activity: 115
Merit: 10
April 09, 2013, 04:31:40 PM
#3
I have a few cards 7970

Half of them gives 700, another almost 530
What is the reason no one can not explain, I have to run them with the same settings on the same computer.
It is believed that the blame for the BIOS video in which different versions of the AMD APP but how to change it (what?) I do not know.
M3t
newbie
Activity: 42
Merit: 0
April 09, 2013, 04:27:07 PM
#2
And I have dual 7970s (obviously). They both go at 675 Mh/s at 73 degrees Sad

Help!!

These are my parameters for CGminer: -I 16,16 --gpu-powertune 20 --gpu-engine 1125 --gpu-fan 100 --temp-overheat 82

How do I overvolt/undervolt and what is the advantage to doing that?
M3t
newbie
Activity: 42
Merit: 0
April 09, 2013, 04:20:13 PM
#1
Shouldn't they be getting upwards of 800?

They are currently on Crossfire (I've taken it off crossfire mode, and they still compare the same).

The drivers are:

Catalyst Beta 13.3
AMD-SDK 2.8
Driver package version 12.10.17-130320a-154717E-ATI
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