Bitcoin Forum

I am a newbie miner.  I appreciate all the info already posted on this forum. 

I am wondering if the hash rate Im getting is what should be expected?

I have 3X Gigabyte AMD Radeon HD 7970 OC 3GB
Mobo: GIGABYTE GA-990FXA-UD3
1200W PSU
8GB RAM
AMD Athlon II X2 270 Regor 3.4 GHz
windows 7

I am running Bitminter pool for Bitcoin

1st GPU: 573 Mhps
2nd GPU: 574 Mhps
3rd GPU: 355 Mhps
Total: ~1450 Mhps

Another question, why is the 3rd GPU going slower than the other 2?

Forget what the pools says for hashrate - it's always an estimate based on how many shares you submit in a given time.  If you submit 0 shares in a minute it guesses your hash is 0, if you submit 5 shares it guesses 350MH/s.

What is important is what your miner is reporting your machine is doing.  If the miner shows #3 significantly lower then that's an issue (assuming they're all the same).

Thanks for the info.

Yes they are all the same model of Gigabyte 7970.  I think it might have something to do with which PCI slot I used for the third graphics card?

my Mobo is GIGABYTE GA-990FXA-UD3

Any common reason why the third GPU would be much lower?

Well is your miner reporting a lower hashrate?  Are you using CGMiner?  GUIMiner?  BAMT?

Dr G,

I am using Bitminter.com since it has a JAVA application and is very easy to use.

I did some research on AMD Vision Engine Control Center and it looks like the PCI is different for the third chip.

My first 2 GPU's show Maximum Bus Setting of PCI Express 2.0 x16

The last one is showing PCI Express 2.0 x4.


Anyway to fix this?

Thanks

My miner is reporting the following hash rates

1st GPU: 573 Mhps
2nd GPU: 574 Mhps
3rd GPU: 355 Mhps
Total: ~1450 Mhps

My mobo

http://www.gigabyte.us/products/product-page.aspx?pid=3894#sp


1.2 x PCI Express x16 slots, running at x16 (PCIEX16_1, PCIEX16_2) (Note 3)
2.2 x PCI Express x16 slots, running at x4 (PCIEX4_1, PCIEX4_2)
3.2 x PCI Express x1 slots
(All PCI Express slots conform to the PCI Express 2.0 standard.)
4.1 x PCI slot


Looks like I only have 2 PCI Express x16 slots, running at x16.

Ahh, sorry I'm not familiar with Dr. Haribo's custom app (well I know about it just never tried it).

Don't worry that the bus only shows 4x width - that shouldn't affect hash rates since hashing is not bandwidth intensive.  You can mine 7970s a max speed on a 1x connector if you want to.


Are the clocks the same on all 3 cards?

I had an issue when crossfire was enabled my cards would not hash at the same rates.  I had to disable it others have had to enable crossfire.  Cant hurt to try if you haven't.

Are the clocks the same on all 3 cards?

-They are the same exact 3 cards and I have not touched any of the speeds on any of them. 

Dr. G,

I see now that the third one is running at 500 Mhz and not 1000 Mhz.

Why would that be?

Actually, it keeps jumping from 1000 Mhz to 501 Mhz

It could be the card is thermal throttling.  The cards will automatically pull back on clocks if they're getting so hot they're going to die.  What are your temps like?

It could also be power but that's probably not the case... when you say 1200W PSU, is it a crappy no name brand or a quality one?

3 7970 will generate a lot of heat , are you monitoring it with msi afterburner ( or other software) ?

Im not monitoring it.

My heat is around 85-90 C

That's pretty hot and I think DrG is probably right about the throttling.  Are these all side-by-side in a case, or do you have these in, or are they in some type of open air rig?  What are your fan speeds set at and do you have any secondary cooling help move the air?

They are all in a case side-by-side.

I just added a fan to blow fast air directly onto the GPU's.

Thanks for all the help and advice though. 

WOW

Temperature is down to 67 degrees Celsius.

Fan speed down to 86% from 100%

3rd GPU up from 360 MHash to 530 Mhash.

Think I fixed the problem.

Thank you all. 

A simple fan lol

cooling is important. there's a reason the biggest miners are using open air setups.

cheers

Hooray for ventilation  ;D

you do realize your gpu is hot enough to cook eggs on a frying pan with right... like boil water hot.... dammmmmm man...... gotta be nice to your gpu's. those honey's are makin you money. cool em off with a few extra fans if you can manage, or lower the temps in your computer room. if your gpu is getting that hot and your not complaining about the heat in the room... congrats.

and i thought mine was bad for getting up to 65C.... lol

i could see the mistake being made though if you were mistaking the temp for F and not C. lol