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Bitcoin => Bitcoin Technical Support => Topic started by: Sebz4n on June 10, 2011, 10:41:21 AM



Title: OC Radeon HD5850?
Post by: Sebz4n on June 10, 2011, 10:41:21 AM
Hey guys!

My ATI Radeon HD 5850 current puts about about 285 MHash/s and has a temp. of 80-90* C during the summer. Non-OC.

GPU Clock is 760MHz and Memory Clock is 1050MHz, should I OC?

How much would the cards temperatur increase, how many MHash/s can I push out extra, and how much can I OC it (What values)?


Title: Re: OC Radeon HD5850?
Post by: sanchaz on June 10, 2011, 11:57:44 AM
downclock memory shoud decrese temps. i wouldnt go over 80, some people state 90 as the max. i try to keep mine below 70º.
what percentage is ur fan at?


Title: Re: OC Radeon HD5850?
Post by: Sebz4n on June 10, 2011, 12:16:47 PM
I have two 5850 cards in crossfire, the primary one (first attached) has its fan blocked by the second card, so it easily runs up to 90* C, and above 100 if I don't decrease so it only runs at 100-150 Mhash/s as oppose to 280 Mhash/s.

Both cards run at 100% fan speed, removed the tower side for better airflow and mounted a fan to point directly at them.

I only wanna OC the secondary card, as I use the primary one to game on (or so I think at least, I assume it uses that as the second already is under heavy activity?), should I downclock memory and increase GPU Clock?


Title: Re: OC Radeon HD5850?
Post by: sanchaz on June 10, 2011, 02:40:23 PM
i wouldnt increase core clock, those temps seem high.
and the fan being blocked humm not a good idea i would say. isnt there anyway to put them more apart with more space?


Title: Re: OC Radeon HD5850?
Post by: Sebz4n on June 10, 2011, 02:48:25 PM
If I can overclock the GPU Clock nor the Memory Clock, it'll be hard to overclock :P


Title: Re: OC Radeon HD5850?
Post by: grndzero on July 12, 2011, 07:20:54 PM
Have you set the fan speed manually? The stock fan settings on most card run pretty hot. Try manually setting the fan speed to 80-100% and see if it lowers the temp.

Also most cases do not provide enough airflow to cool cards properly. Try leaving it open and see if that makes a difference.


Title: Re: OC Radeon HD5850?
Post by: Wuked on July 13, 2011, 10:55:51 PM
Hey Guys,

I'm getting about 360-370Mh/sec on my 5850s.

Remove the plastic shrowd if it has one, and setup a desk fan or something else moving air over them.

Change the core speed to around 910 and the memory to 300 using ATI Clock tool in windows, or ATI tool in Linux.


Title: Re: OC Radeon HD5850?
Post by: grue on July 14, 2011, 01:21:06 AM
if your card can overvolt, you can get at least 400 MH/s (assuming cooling is adequate).

http://i.min.us/ieqIfy.png
dont mind the rejects, they were caused by internet failure.


Title: Re: OC Radeon HD5850?
Post by: MysteryMiner on July 14, 2011, 09:55:44 AM
Don't expect or suppose the hardware to be able to deliver more than factory default's. Every piece of chip is unique. Some might have greater overclock potential, some might run only at default speeds. Only experimenting will show you what your hardware is capable of.

The 760MHz is already overclocked! The HD5850 default frequency is 725MHz.