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Topic: Low hashrate on 7970 scrypt? Under 700Kh/s? Here's what to do... - page 6. (Read 53750 times)

member
Activity: 98
Merit: 10
I've got a lot of different 7970 cards and the XFX ones are the worst i've ever used. My Gigabyte ones will fly over 700 a piece of cake, my Diamond ones will do over 600 without much effort, but the XFX ones i'd be lucky to hit 550 no matter how much tweaking or OC'ing.
hero member
Activity: 1232
Merit: 516
One of the keys to your tuning is that you are using 2 GPU threads.  Older series cards like only 1 GPU thread.  This presents a problem in a mixed environment.  For example, I have two 58030's and one 7970.  I have to use -g 1 to get the 5830's to hazh at ~290kH/s, but that drops the 7970 from 730kH/s to ~600kH/s.

Have you tried running the cards in separate instances of cgminer? Sounds like that might sort your issue out.
newbie
Activity: 56
Merit: 0
Did you change it in the .conf file rather than trying to add it to the command line?
hero member
Activity: 630
Merit: 500
One of the keys to your tuning is that you are using 2 GPU threads.  Older series cards like only 1 GPU thread.  This presents a problem in a mixed environment.  For example, I have two 58030's and one 7970.  I have to use -g 1 to get the 5830's to hash at ~290kH/s, but that drops the 7970 from 730kH/s to ~600kH/s.

Hmmm, surely you can set -g1 for one card and -g2 for the other..?
I tried some config options and it wouldn't let me.  If anyone knows how I'm all ears.
newbie
Activity: 56
Merit: 0
One of the keys to your tuning is that you are using 2 GPU threads.  Older series cards like only 1 GPU thread.  This presents a problem in a mixed environment.  For example, I have two 58030's and one 7970.  I have to use -g 1 to get the 5830's to hash at ~290kH/s, but that drops the 7970 from 730kH/s to ~600kH/s.

Hmmm, surely you can set -g1 for one card and -g2 for the other..?
newbie
Activity: 56
Merit: 0
As you can see i've been playing about with MSI Afterburner settings, still haven't got the sweet spot quite right, it's amazing how sensitive these cards are to such small changes.

What MSI? what Afterburner? What cgminer?

Urrrm.. You can clearly see the versions i'm using in the picture... and MSI is MSI Afterburner...
sr. member
Activity: 322
Merit: 250
Supersonic


As you can see i've been playing about with MSI Afterburner settings, still haven't got the sweet spot quite right, it's amazing how sensitive these cards are to such small changes.

What MSI? what Afterburner? What cgminer?
hero member
Activity: 630
Merit: 500
One of the keys to your tuning is that you are using 2 GPU threads.  Older series cards like only 1 GPU thread.  This presents a problem in a mixed environment.  For example, I have two 58030's and one 7970.  I have to use -g 1 to get the 5830's to hash at ~290kH/s, but that drops the 7970 from 730kH/s to ~600kH/s.
hero member
Activity: 1395
Merit: 505
Your desktop background looks like it has a high hash rate probably adds an extra 50 kh/s !
newbie
Activity: 56
Merit: 0
For anyone interested, i managed to get 800Kh/s stable (so far anyway), made a thread with details here: https://bitcointalksearch.org/topic/m.2121006
newbie
Activity: 56
Merit: 0
So i managed to get up to 800 Kh/s on the 1st card, although i've only just noticed a few hardware errors, it's been running a fair few hours.

I'm gonna tweak it tomorrow, i'll post the results. Gotta sleep now.



newbie
Activity: 56
Merit: 0
I remember you from the trollbox on BTC-E, I'm going to need this thread later. I'm getting 3 of the gigabyte 7970 OC cards soon.

Ah yes, good ol' trollbox Tongue

I actually like that thing, met some nice people Smiley
newbie
Activity: 27
Merit: 0
I remember you from the trollbox on BTC-E, I'm going to need this thread later. I'm getting 3 of the gigabyte 7970 OC cards soon.
newbie
Activity: 56
Merit: 0
Cheers Bud Smiley

In my experience you can get pretty much the same hash rate with a thread concurrency of 8192 as you can with a higher one, but then all the other settings need adjusting.

As long as you are careful, i wouldn't worry too much about damaging your card through changing the voltage.

I am finding that many cards have a stock voltage way higher than needed - for example the stock voltage on my vapor-x is 1.256V, and that produces way too much heat.

I think mine were 80+ before i downed the voltages. Now the first card is 60C fans 50% and the second card is 70C fans 70% - I have a pci riser card in the mail though, so that should get both temps down to 60C which is more than optimal imo.

Download MSI afterburner 2.2.2 and have a look at the voltage. If it's 1.2V+ you could definitely lower it a bit which should noticeably reduce heat. It depends on your clock speed and card obviously, but i find a nice 40-60mV gap between clock speed and voltage give nice stability - i.e 1040 GPU speed, 1080mV Voltage.

Let me know how it goes Smiley
member
Activity: 67
Merit: 10
Great write-up!

I just purchased an xfx hd7970 and noticed that the tc for that card will not go as high as my powercolor hd7970.  Didn't think there would be that much difference between the cards.  haha, guess I'm still new to this too!

Very interesting about the voltage, I've been a little couscous about messing with those setting as they can end up damaging the card if not done right.  With adjusting the voltage from stock have you noticed the cards running cooler at the same hash rates?  I had to lower the hash rates of both my cards down to just above 500 KH/s (scrypt) in order to keep the heat down.  Maybe an open frame design with a box fan is next Smiley.

Keep it up man!
newbie
Activity: 56
Merit: 0
Hi guys,

So i'm new to this game, about 3 weeks in now. One of the most frustrating problems i came across, was that my 2 7970's both got 700+Mh/s on sha-256 but when it came to scrypt they were only getting about 550Kh/s.

I spent a solid week searching for answers - I have noticed so many people with the same problem - and there are lot's of responses about how certain 7970's are just crap and you should sell them blah blah well anyway that's rubbish - Most if not all 7970's should be able to get 700+Kh/s.

Some of you will have just not set them up properly and won't need to flash, but, there are specific cards that for some unknown reason seriously under perform on scrypt. Luckily, the solution is rather simple.

Now, just to clarify, all the setting i state are for a sapphire vapor-x ghz edition, so they may vary for other cards.

I can confirm i have gotten peoples gigabyte and xfx cards up to these speeds, and my own is currently hashing at 730Kh/s. It is usally the ghz/vapor-x/ possibly OC editions that need flashing.

Oh and one other thing - if you think your card is voltage locked, try MSI afterburner version 2.2.2 and Sapphire Trixx, as some cards that people claim to be voltage locked are not when using Trixx or older MSi software.

Before we go as far as flashing, try the following:

Before running cgminer, open cmd, type  "setx GPU_MAX_ALLOC_PERCENT 100" (no quotation marks) and press return, then close cmd.

Change your MSI afterburner settings to the following:

GPU Clock - 1040Mhz *
GPU Voltage - 1100Mv
Memory Clock - 1500Mhz
Memory Voltage - 1500Mv

*This is the optimal value for one of my identical cards, the other one get's a much lower hashrate with this value so i use 1025Mhz which get's 730Kh/s as well - It will be specific with each unique card, and it's more about the ratio of the GPU to memory speeds than how high they are. With scrypt 1Mhz can easily make a 20Kh/s+ difference in hashrate.

EDIT - I have noticed something peculiar about the vapor-x cards. Sometimes the hashrate is very stable, stays at the same value, but if i change something suddenly the hashrate will be up and down like a yo-yo.
         The strange thing is, this doesn't seem to be because  for e.g there's not enough voltage or your clock speeds are too high. I found that is the difference between memory voltage and clock OR              
          GPU Voltage and clock that causes this in my experience, if it's too big a difference you have problems, if it's too small a difference you have problems. Hope this helps if you've noticed this issue.

The trick is to find the sweet spot - Start at 1040, find whether going up or down increases hashrate, then keep moving GPU speed in that direction untill the hashrate suddenly goes down, back up 1 or 2Mhz and that should be the optimal clock settings for 1500Mhz memory - if you then decide to change memory speed you will need a totally different gpu speed.

Then go into a fresh cmd window and type:

cgminer --scrypt -o yourpool -u yourusername -p yourpassword -s 2 --expiry 1 --queue 0 --thread-concurrency 20992 -I 13 -w 256 -g 2

Also try 8192.

If your hashrate is still only 550Kh/s - 650Kh/s then a bios flash will be necessary.

**WARNING - If you mess up, there is a small chance you may brick your card**

Luckily with certain cards i.e the vapor-x you have a switch that can switch between 2 different BIOS. So if for some reason after flashing you are unable to boot (i can't imagine any reason this would happen, but still), just push the switch and boot off the second BIOS then re flash with the original BIOS. If you don't have the switch and for some reason you can't boot, you will need to boot off another graphics card and re flash the bios back to original.



Ok so here's what you need to do, you will need a USB flash drive:

1. First of all you need to make the flash drive bootable. This software should do the trick: http://rufus.akeo.ie/

2. Next Download the BIOS for your card from this website: http://www.techpowerup.com/vgabios

As for what BIOS you need, this depends on your card. For the Sapphire 7970 this one worked for me: http://www.techpowerup.com/vgabios/129658/sapphire-hd7970-3072-120926.html

Say you have a Gigabyte 7970 Ghz - You want to flash with the Gigabyte 7970 BIOS for a NON Ghz edition version of the card.

Then download atiflash: http://www.techpowerup.com/downloads/2230/atiflash-4-07/

Feel free to rename your bios to new.bios to make life easier further along.

3. Copy both files over to the bootable USB you created earlier.

4. Restart your PC. Go into your motherboard BIOS and set your boot device priority so the USB drive is first, save and exit. (don't forget to switch this back to your operating system drive after your done)

5. Right so if everything is going well, atiflash should boot (a black screen like cmd if i remember correctly). Type the following and press return: atiflash.exe -i

That will tell you the device number to use in the next step.

6. Then type the following and press return, where 0 is your device number and new.rom is the bios name, or leave it the same if you renamed it: atiflash.exe -f -p 0 new.rom

Once complete, reboot and keep your fingers crossed Wink

Go through the steps i wrote first, varying your GPU speed to find the best value.

HOPEFULLY that should do the trick.




Pleas let me know if i haven't explained something properly, or if anyone needs any help with it, post back and i will try my best.

Hope this helps Smiley

Edit - I think this also works for under performing 7950's but obviously not as high and different settings across the board.

Edit - Well i got bored, so here's some proof for any doubters.. and a nice tidy blond piece to go with it Tongue



As you can see i've been playing about with MSI Afterburner settings, still haven't got the sweet spot quite right, it's amazing how sensitive these cards are to such small changes.
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