Author Topic: XFX 7970 Low Hash Rate  (Read 10498 times)

Offline clust0

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XFX 7970 Low Hash Rate
« on: April 15, 2013, 08:43:22 PM »
Hello,

I am getting low performance with this hardware:
- 2 x 4GB Kingstong 1666mhz
- Mother Gygabyte 990FX UD5
- 2 x XFX 7970 3GB Double dissipation
- Micro Sempron 145

I cannot reach 700 kh/s with 2 gpu's, may I am experiencing a CPU bottleneck? I have read that a Sempron 145 would be enough for this configuration.

Attached is the cgminer configuration and it's performance.
Please help me,


Offline gfoot

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Re: XFX 7970 Low Hash Rate
« Reply #1 on: April 15, 2013, 09:40:27 PM »
XFX cards specialize in low hash rates.

Still, those are extra low.  My best - for a single XFX 7970 GHz - is somewhere north of 500kH/s, but not by much, with a WU of about 470/m.

Set gpu-powertune to 20 - you can do it dynamically via the G/C menu.  That should get you 50kH/s-100kH/s more per card.

I would suggest sticking to the default clocks of 1050 and 1500 - I haven't found any tangible benefit from changing them and whenever I do, going back to the default settings seems to make the card much happier.  Especially the memory rate.

Also perhaps drop gpu-threads to 1?  Unless it needs to be 2 because there are 2 GPUs... I'm not sure about that.  I had mixed results from high thread counts - sometimes it seemed to help, but not consistently.

I also wonder whether there's a cooling/throttling problem with one of your cards - the hotter card is performing worse than the cooler card.
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Offline clust0

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Re: XFX 7970 Low Hash Rate
« Reply #2 on: April 16, 2013, 12:40:11 AM »
I lowered gpu clock and memclock and I am getting 412 kh/s right now for each gpu :)

By the way, I think it is still very low....What do you think about having a botteneck with my CPU Sempron 145?

Offline bwang008

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Re: XFX 7970 Low Hash Rate
« Reply #3 on: April 16, 2013, 06:06:36 AM »
sempron 145 works fine for a mining rig.

it's your configuration.
ltc:LVGX1jYQY6TM3UNkgvrw3giWnZzDpo6dKP

btc:1MsRHYKBkgw3S8wUiA9WjFoiuk1sDRRhNY

Offline clust0

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Re: XFX 7970 Low Hash Rate
« Reply #4 on: April 16, 2013, 08:01:22 AM »
Which parameter do you recommend to modify?

Offline pintycar

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Re: XFX 7970 Low Hash Rate
« Reply #5 on: April 16, 2013, 09:20:51 AM »
I'm sorry I can't help you but have a look at our Sapphire 7970 Vapor-X GHz ed. because it would appear as we all have the same issues with these non-ref designs.

P.S.: Sempron 145 is definitely more than enough ;)

Offline cal97g

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Re: XFX 7970 Low Hash Rate
« Reply #6 on: April 16, 2013, 11:16:08 AM »
Why don't you check your CPU usage? Running top in terminal should do it.

Also, it might be because your running in a virtual machine..

Offline clust0

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Re: XFX 7970 Low Hash Rate
« Reply #7 on: April 16, 2013, 02:55:02 PM »
it's not a virtual machine, it's a temviewer session.

Offline gfoot

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Re: XFX 7970 Low Hash Rate
« Reply #8 on: April 17, 2013, 12:48:01 AM »
Regarding XFX DD 7970 having poor LTC hash rates, I swapped mine over to mining bitcoin, and straight away with no real settings tweaking it got respectable hash rates.  With some gentle overclocking it's now getting about 650MH/s, squarely in the mid range of the 7970s on the wiki hardware comparison, with the right kind of WU figure (about 10/m).  So it looks like whatever problems these cards have with mining are restricted to LTC.

So maybe there's something weird about the memory, bus, or cache.
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Offline clust0

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Re: XFX 7970 Low Hash Rate
« Reply #9 on: April 18, 2013, 06:57:37 AM »
Many thanks all, I 've reached 420 khs with this configuration.
Quote
"intensity" : "13",
"vectors" : "1",
"worksize" : "256",
"kernel" : "scrypt",
"lookup-gap" : "0",
"thread-concurrency" : "8192",
"gpu-engine" : "925",
"gpu-memclock" : "1375",
"shaders" : "2048",
"gpu-threads" : "1",
"gpu-powertune" : "20",
"scrypt" : true

Offline MinerInTheShire

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Re: XFX 7970 Low Hash Rate
« Reply #10 on: April 18, 2013, 08:16:42 AM »
Looks like I made the same mistake in getting a XFX 7790 (Black Edition DD OC). I'm getting around 520Kh/s stable. Anything above that either makes the system unstable, or the hashrate jumps around so one second may be 680Kh/s, the next is in the 200's, the next is in the 600's, the next is in the 300s, the next is in the 500's, etc, etc - with an average of around 400/500 Kh/s.... So I've just stuck to the stable 520Kh/s rate.

I've found that setting gpu-powertune and thread-concurrency manually negatively affects my hashrate, as does not specifying shaders manually.

I also wondered if my system was a bottleneck, but it doesn't appear to be - CPU usage is genearlly around 1 - 5% (with peaks a few times a minute of about 10% and 20%), and memory usage is pretty static at 1.18GB. I have an old (2007-ish) HP XW9400 workstation, with two dual Opteron 2.4Ghz (2216) processors and 8GB RAM in it.

I want to add another 7970, but don't think it'll be an XFX card...

Offline gfoot

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Re: XFX 7970 Low Hash Rate
« Reply #11 on: April 18, 2013, 08:38:41 AM »
Choose carefully.  It looks like some other GHz edition cards from other brands have the same problem, but also some people report good results from certain brands even in the GHz editions.  So there's nothing conclusive.  I won't name-check the brands that seem to get positive results, as it's not first-hand evidence, but if you browse around the threads you'll see which brands and models people have most success with.

It may also be better to get a 7950 instead - people report great hash rates from those and they are cheaper too.

My XFX DD 7970 is currently mining bitcoin at reduced clock rates as an experiment - the card was a waste of money, but underclocked (700MHz & 1500MHz, 1.1V) the temperature stays down even with the fans at very low speed, and if I can get a trickle of BTC out of it then at current rates then it should at least cover the cost of running the PC.
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Offline MinerInTheShire

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Re: XFX 7970 Low Hash Rate
« Reply #12 on: April 18, 2013, 09:27:49 AM »
gfoot - Great advice, cheers. One thing I've noticed also, whilst looking for potential second cards, is that there appear to be not only a lot of different versions of 7970s from brands, but also multiple revisions of many of those versions.... I suppose it comes now that the 7970's are a maturing product.

From what I can gather, "stock" reference 7970's seem to do the best... But when manufacturers are pushing out revisions, quite often they're moving away from the ATI reference model...

You mention 7950's... Bang for buck they're looking like a better buy than 7970's - assuming they hash at the rates I'm seeing people post at... The XFX isn't, but that's my own fault for not doing more due diligence and just looking at the bottom line price, that it was a 7970 and clock rates. D'oh! If I could get a second 7970 in this rig that got closer to the 650 mark, then whilst it may be a little less economical right now, it would give me an increased hash rate whilst the difficulty is lower than it would be when I added more hashing power in a month...?

Offline MinerInTheShire

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Re: XFX 7970 Low Hash Rate
« Reply #13 on: April 18, 2013, 10:53:08 AM »
Just for information.... I previously had a play with clock speeds on my XFX GHz card.... And didn't have much luck, so just reverted to the stock 1000/1425 resulting in a stable 520Kh/s. However I've had a play again after noticing that the ATI reference clock speeds for GHz cards is 1050/1500. Using those clock speeds gets me a stable 540Kh/s, and playing a bit further I can get a stable 555Kh/s from 1125/1530 clock speeds.

Offline astrokev

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Re: XFX 7970 Low Hash Rate
« Reply #14 on: April 21, 2013, 07:20:27 PM »
I've got a pair of the XFX 7970's which actually had been performing *worse* (~~ 350kh/s) than my xfx 6950's (~~ 415kh/s) for LTC mining.  BTC mining they work pretty well.

I have been tweaking awhile now and have them running stable with some major memory overclocking.  I'm still working on this so i expect to be able to still eek out a bit more, but here is where I'm at:

Using:
Code: [Select]
-g 2 -I 18 -w 256 --gpu-powertune 20 --lookup-gap 2 --shaders 2048 --gpu-memclock 1900 --gpu-engine 1050

is rolling about 530 kh/s on these cards and 73C.  fans are a bit irritating in that they turn on hard/gentle every few seconds.




« Last Edit: April 21, 2013, 07:52:45 PM by astrokev »