Bitcoin Forum
December 11, 2016, 08:28:53 AM *
News: To be able to use the next phase of the beta forum software, please ensure that your email address is correct/functional.
 
   Home   Help Search Donate Login Register  
Pages: [1]
  Print  
Author Topic: How do I stop large M/hash fluctuations in GUIminer?  (Read 2824 times)
bartonn
Newbie
*
Offline Offline

Activity: 12


View Profile
May 14, 2011, 07:52:10 PM
 #1

I have recently setup a new mining rig.  here are the specs below:
msi 750i motherboard
core 2 duo e6600
4gb ddr2
xfx 5830 (235M/hash)
sapphire 5850(275M/hash)
asus directcu 5850(275M/hash)
windows xp OS
750w psu
I have been mining on the computer for close to a week now, and always get the same M/hash with minimal fluctuations.  I have msi afterburner installed, and I would always have 100%gpu usage on all of my cards.  Today, I tried to overclock my asus 5850.  I increased the clock to 775mhz, but the m/hash on my other cards started to fluctuate, so i reset it to stock.  However, my 5830 and sapphire 5850 now has large m/hash fluctuations.  The 5850 varies from 180-240 M/hash and the sapphire 5850 varies from 200-275 M/hash,  but the asus 5850 is unaffected.  also, whenever I enter msi afterburner, my asus 5850 is always at 100% usage, but the 5830 and sapphire 5850 usage fluctuates between 80-97% usage. 
What could be causing the problem?
Advertised sites are not endorsed by the Bitcoin Forum. They may be unsafe, untrustworthy, or illegal in your jurisdiction. Advertise here.
1481444933
Hero Member
*
Offline Offline

Posts: 1481444933

View Profile Personal Message (Offline)

Ignore
1481444933
Reply with quote  #2

1481444933
Report to moderator
zimpixa
Member
**
Offline Offline

Activity: 98


View Profile
May 14, 2011, 08:01:56 PM
 #2

Maybe little low PSU? Its rather recommended to have ~700W PSU for 2x 5850 and u have additional 5830.

Also if you want to get it to normal stage reset your PC. Should solve it.

YinCoin YangCoin ☯☯First Ever POS/POW Alternator! Multipool! ☯ ☯ http://yinyangpool.com/ 
Free Distribution! https://bitcointalk.org/index.php?topic=623937
bartonn
Newbie
*
Offline Offline

Activity: 12


View Profile
May 14, 2011, 08:09:56 PM
 #3

I ran a test on my pc.  The 5830 and the sapphire 5850 ran stable without the asus 5850.  however, when i started the asus 5850 the M/hash began to fluctuate.  So it seems my psu can't handle all my cards.  however, I was able to run it for a week and my psu handled it fine.  When i overclocked the asus 5850, could there be any settings left over that allowed it to draw more power?
thanks
Kluge
Donator
Legendary
*
Offline Offline

Activity: 1218


Michael, send me some coins before I hitman you


View Profile
May 14, 2011, 08:10:38 PM
 #4

Maybe little low PSU? Its rather recommended to have ~700W PSU for 2x 5850 and u have additional 5830.

Also if you want to get it to normal stage reset your PC. Should solve it.

This is possible. Each 5850 consumes roughly 200-225 watts at full load when overclocked. The 5830 consumes slightly less. That comes out to ~600-650w power consumption on the cards alone. After including the CPU, MoBo, RAM, & whatever peripherals you may have, you'll probably want at least a 850w PSU.

Don't mix your coins someone said isn't legal
dikidera
Full Member
***
Offline Offline

Activity: 126


View Profile
May 14, 2011, 08:13:43 PM
 #5

Erm sorry, but the 5850 consumes 151 watts at full load at stock speeds.
The 5830 should be a bit less
Kluge
Donator
Legendary
*
Offline Offline

Activity: 1218


Michael, send me some coins before I hitman you


View Profile
May 14, 2011, 08:24:39 PM
 #6

Erm sorry, but the 5850 consumes 151 watts at full load at stock speeds.
The 5830 should be a bit less

I should've noted "when overclocked 200MHz+"

My PC's pulling 480w from the wall with an underclocked & down-volted 3-core AMD CPU running @ 66%, with no peripherals, one SSD, and just one stick of RAM, which I take to mean almost the entire power draw is coming from the two 5850s I have in there.

Still, OCing that little bit may have pushed his PSU over the edge.

Some power supplies have very significant output degradation with heat increase. Simply cooling the PSU better may correct the problem the OP is having. It's a very common problem in laptops, and not impossible in desktops. The intake fan/vent gets clogged up, heat builds up, and output deteriorates. Many owners of gaming laptops find their laptop starts giving BSoDs after a year or few of ownership when it worked perfectly fine originally, and it turns out just giving it a good cleaning fixes it. If it is that problem, it could also be from the days getting hotter depending on where he lives.

Don't mix your coins someone said isn't legal
Kluge
Donator
Legendary
*
Offline Offline

Activity: 1218


Michael, send me some coins before I hitman you


View Profile
May 14, 2011, 08:33:24 PM
 #7

Try fiddling with (or removing) the -f flag, too. Try out -f 150

Don't mix your coins someone said isn't legal
bcpokey
Sr. Member
****
Offline Offline

Activity: 462


View Profile
May 14, 2011, 09:41:50 PM
 #8

How are your cards configured? Might be thermal throttling as well, if you've stuffed all the cards close together.

Unless he has a signficantly inferior PSU this is unlikely to be the problem. Running 2 5870s OC'd 100Mhz and a 5850 OC'd 100Mhz with downclocked VRAM (make sure to do that OP) and a CPU @ 100% load, a few fans and an HDD my rig pulls 550W from the wall, which is probably closer to 475W from the PSU.
This is a significantly higher power draw systsem than 2x5850s and a 5830, which would definitely not draw anywhere near 600Watts.
bartonn
Newbie
*
Offline Offline

Activity: 12


View Profile
May 14, 2011, 09:51:52 PM
 #9

thanks for the help.  I believe my pc may be too hot, and either the GPUs or my power supply cannot handle the heat, since my room is probably over 80 degrees F.  soon, I plan to better cool the computer. 
thanks again
d3athrow
Newbie
*
Offline Offline

Activity: 23


View Profile
May 14, 2011, 10:29:52 PM
 #10

xfx 5830 (235M/hash)

<offtopic>you only get 235mh/s with your 5830, i get 260 with mine at stock and 290 at 1000mhz core</offtopic>
Pages: [1]
  Print  
 
Jump to:  

Sponsored by , a Bitcoin-accepting VPN.
Powered by MySQL Powered by PHP Powered by SMF 1.1.19 | SMF © 2006-2009, Simple Machines Valid XHTML 1.0! Valid CSS!