HD 5850 OC question

[MikeScott]

Hey guys, so after getting some help on the New Builds forum here I have finally settled on my new gaming PC. I am going with the i5 750 on an ASUS P7P55D and have heard/read that it will be quite fun and easy to OC safely.

But... my 2 Sapphire HD 5850s are being shipped to me as we speak and while I have seen some stuff on OCing a single 5850, I haven't seen anything on OCing them while crossfired.

Was just wondering if anyone had already safely done it/has results from doing this, or has any advice on the subject.

Thanks a bunch from a total overclocking noob. :)

[mattlef]

You'll have to flash each GPU to an unlocked asus bios to overclock. Sapphire locks their bios to only allow for minimal overclocking :S
With the stock cooler, you can get decent performance increases. You can overclock each card individually in CCC or using Afterburner from MSI.

Shoot me a PM if you need my help with the build. I'll try to help the best I can from windsor lol.

[Dr_BenD_over]

My BIOS isn't locked, oh wait, I bought an Asus card this time and not a Sapphire one. If Rivatuner has been updated you should be able to use it to bypass the CCC limitations in much the same was as had to be done with the 4770's (I should have a thread on here somewhere about it - I'll dig around)

[Surfer_2099]

I have a Gigabyte Radeon 5850 and, using AMD GPU Tool, run it at 875/1150 without heat or stability issues. If I run the memory even 1 Mhz higher, I run into lots of issues but that is pretty standard for ATI cards. I have always found the memory to be the biggest limitor in respects to Overclocking.

There is an article in the Round Up on the splash page from last week (I think) where Overclockers.com pushed their 5850 to pretty high numbers by increasing the voltage a bit. Myself, I don't feel the need to push it that far so I only run the higher clocks when I plan on running really intensive games or when I am benchmarking. Otherwise, I just leave my frequencies at stock.

Good luck!
Happy_OC_Canuck :)

[Dr_BenD_over]

OK

Here's the method I used to bypass the locks on my 4770's ATI Radeon HD 4770 Video Card Overclocking Guide - How to Overclock The Radeon HD 4770 - Legit Reviews There has to be something similar for the 5850's, some of the clocks they're being limited to are pathetic, I saw one card that was limited to 775/1125. The Asus BIOS will allow for 1200/1400 but flashing the BIOS tends to void the warranty with some companies.

The clocks of each card can be set seperately and really you should find their maxes seperately. However when you bring both cards together in CF you'll probably find you can't get quite as high clocks on each card as you could with only one installed. Running something like Furmark to stress the card after each tiny adjustment is also a good idea. Avoid using the CCC's Auto tune feature at all costs.

[Bojamijams]

I flashed with the MSI bios and use the MSI Afterburner tool to get the clocks I'm at. Max voltage

[Surfer_2099]

Originally Posted by Dr_BenD_over

OK

Here's the method I used to bypass the locks on my 4770's ATI Radeon HD 4770 Video Card Overclocking Guide - How to Overclock The Radeon HD 4770 - Legit Reviews There has to be something similar for the 5850's, some of the clocks they're being limited to are pathetic, I saw one card that was limited to 775/1125. The Asus BIOS will allow for 1200/1400 but flashing the BIOS tends to void the warranty with some companies.

The clocks of each card can be set seperately and really you should find their maxes seperately. However when you bring both cards together in CF you'll probably find you can't get quite as high clocks on each card as you could with only one installed. Running something like Furmark to stress the card after each tiny adjustment is also a good idea. Avoid using the CCC's Auto tune feature at all costs.

Typically, 775/1125 is the maximum CCC Overdrive settings that it will permit. Using other software like AMD GPU Tool or perhaps ATI Tool or Riva Tuner (I have not tested those last two) would permit you to take it past the CCC limitations and increase voltages if you would like.

Cheers!
Quick_Post_Canuck :)