Bitcoin Forum

Bitcoin => Bitcoin Technical Support => Topic started by: ChaosFox on August 28, 2011, 04:46:35 PM



Title: Possible power issue when card is under stress... but where?
Post by: ChaosFox on August 28, 2011, 04:46:35 PM
Greetings there, Bitcoiners.  ;)

I'd like to kindly ask for any helpful input for some issues I've been having as of lately. Not too long ago, I upgraded my system, and replaced my battle-weary GeForce 9600GT with a spanking new Radeon HD 6850 (For motives unrelated to Bitcoin mining originally, though it does mine fairly well. ;D ). For a while everything went perfectly, but starting about a week ago, I've noticed that after mining for a bit, the LCD screen would turn blurry, wobbly horizontally... it's rather hard to explain, but it's like horizontal lines were moving back and forth in the screen. As soon as I stop mining, the problem disappears. This doesn't just happens when mining- running FurMark for a while creates the same issue, though apart from this, I don't see any other noticeable artifacts, not the usual suspects at least. (Black squares, weird textures, polygons stretching freakishly, etc.) I can attach a screenshot of the screen while mining or running FurMark, but the wobbling is noticeably absent in any screen cap.

I'm fairly certain it's a power issue, as it only happens when the card is under a lot of stress... but where? The PSU is new, and is rated at 800W which is certainly more than what I would need for that card. Also, checking the voltages in HWMonitor shows that +5V drops to 4.90 at worst, which I believe it is within a tolerable range. Could it be that I'm drawing too much power from the outlet and the monitor is the straw that breaks the camel's back? Has anyone experimented problems similar to these? Thanks in advance.


Title: Re: Possible power issue when card is under stress... but where?
Post by: ruski on August 28, 2011, 05:48:06 PM
Its OCed too far, and/or overheating.


Title: Re: Possible power issue when card is under stress... but where?
Post by: ChaosFox on August 28, 2011, 05:52:58 PM
Its OCed too far, and/or overheating.

I'm running at stock (775 Mhz for core, 1000 Mhz for memory) and the card gets at ~80ºC at worst when running FurMark, it's usually at 70ºC when mining, so I don't think it's either.  ???


Title: Re: Possible power issue when card is under stress... but where?
Post by: bitbites on August 28, 2011, 08:23:22 PM
Return it for a refund. I had a card do this once and I got it replaced under warranty (I actually got an upgrade because the retailer didn't have my card in stock)


Title: Re: Possible power issue when card is under stress... but where?
Post by: Technocrat on August 28, 2011, 08:47:33 PM
What brand is the PSU?
Measure the V(drop) across the 12V line during load.
Use a voltmeter not monitoring software.
GPUs don't use the 5V line.