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5850 CF flashing BIOS to 5870

Soldato
Joined
12 Jan 2009
Posts
6,557
I have two Sapphire 5850 Extreme cards running in crossfire. I'm thinking of flashing the BIOS on both of them to get 5870 speeds. I understand the risks of doing this but surly by now there's a method of doing this providing minimum risk.

Also which is the the best 5870 BIOS to use?

EDIT: ATIWinFlash looks easy to use but doesn't have an option to backup your current BIOS
 
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I tried but I got artifacts and system hangs. Do I have to increase the voltages on my 5850 too?
Of course serious overclocking would require voltage. Just go download Sapphire Trixx for increasing the voltage for the Sapphire 5850 Extreme.

But to be honest, I think CF5850 would run most games nicely even on stock clock, as long as you are not gaming at above 1920 res, and only using 4xMSAA or below in the more demanding games.

Any chance your CPU is holding back your graphics? What are you using?
 
Of course serious overclocking would require voltage. Just go download Sapphire Trixx for increasing the voltage for the Sapphire 5850 Extreme.

But to be honest, I think CF5850 would run most games nicely even on stock clock, as long as you are not gaming at above 1920 res, and only using 4xMSAA or below in the more demanding games.

Any chance your CPU is holding back your graphics? What are you using?

Specs are in my sig. What voltage should I put my crossfire 5850s to get 5870 clock speeds?

EDIT: Did some googling and found the Sapphire cards don't support voltage changes :(
 
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Specs are in my sig. What voltage should I put my crossfire 5850s to get 5870 clock speeds?
Ah sorry didn't notice.

I think you'd best overclock your i5 a bit higher, to may be 4.0-4.2GHz. It's not so much that your CPU isn't faster enough, but it is more about compensate for the shortcoming of lots of games using less than 4 cores, so you'd need the extra power for improving the scaling with your CF5850.

As for overclocking your 5850s, I would say give the voltage a bump of 50mV, and see how high you can push the overclock (I'd start from 850MHz on the core clock). Download Heaven Benchmark 2.5 Basic Version for quick stress testing for checking stability...if the the overclock is very unstable, the graphic driver should crash (or might even black screen and crash your PC) very quickly within the first minute of running the bench. Do the Heaven Bench for about 3 loops to see it doesn't crash. If it is stable in the Heaven Bench, but not stable (crashes) when running games, give the the voltage a tiny bit more bump (say may be another 10-20mV) should stablise it...if not, may be try lowering the core clock a bit.

Also, focus on just overclocking the core clock first and ignore the memory clock, as it affect performance much more. Only when you are certain the overclock for the core clock is stable should you start to overclock the memory clock. Almost all 5850 would overclock the memory clock by at least 100MHz without problem.
 
Ah sorry didn't notice.

I think you'd best overclock your i5 a bit higher, to may be 4.0-4.2GHz. It's not so much that your CPU isn't faster enough, but it is more about compensate for the shortcoming of lots of games not using less than 4 cores, so you'd need the extra power for improving the scaling with your CF5850.

As for overclocking your 5850s, I would say give the voltage a bump of 50mV, and see how high you can push the overclock. Download Heaven Benchmark 2.5 Basic Version for quick stress testing for checking stability...if the the overclock is very unstable, the graphic driver should crash (or might even black screen and crash your PC) very quickly within the first minute of running the bench. Do the Heaven Bench for about 3 loops to see it doesn't crash. If it is stable in the Heaven Bench, but not stable (crashes) when running games, give the the voltage a tiny bit more bump (say may be another 10-20mV) should stablise it...if not, may be try lowering the core clock a bit.

Also, focus on just overclocking the core clock first and ignore the memory clock, as it affect performance much more. Only when you are certain the overclock for the core clock is stable should you start to overclock the memory clock. Almost all 5850 would overclock the memory clock by at least 100MHz without problem.

I can't change the voltage on my Sapphire 5850s, did some google searches and even after changing the cfg file for MSI Afterburner to read UnofficialOverclockingMode = 1 I still dont get the option :(

EDIT: Sapphire Trixxx let me change the voltages! Currently set to 1088. What shall I increase it to?
 
Trixxx is pants, only increased voltage to 1090 and system hanged??? I rather use MSI and stick to one program

Im gonna have to flash the BIOS in order the change the voltage. So what program and BIOS version should I use to do this?
 
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Trixx allows you to change the voltage on cards that Afterburner doesn't though.

Did you try a different version of Trixxx?
 
Trixxx is pants, only increased voltage to 1090 and system hanged??? I rather use MSI and stick to one program

Im gonna have to flash the BIOS in order the change the voltage. So what program and BIOS version should I use to do this?
DO NOT flash the bios on those extreme cards! They are non-reference cards so flashing them to other brands' bios could brick them.

I'm afraid Trixx is the only way to overvolt the Extreme series cards.
 
DO NOT flash the bios on those extreme cards! They are non-reference cards so flashing them to other brands' bios could brick them.

I'm afraid Trixx is the only way to overvolt the Extreme series cards.

Using the latest version of Trixxx here, it lets me change the voltage but when I went up by just 20 my system hung. What voltage shall I try? I really want to get to 5870 speeds on both cards. A Sapphire 5870 runs at 1.200V, my 5850s are currently at 1.088V
 
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Using the latest version of Trixxx here, it lets me change the voltage but when I went up by just 20 my system hung. What voltage shall I try? I really want to get to 5870 speeds on both cards. A Sapphire 5870 runs at 1.200V, my 5850s are currently at 1.088V
Upping voltage alone shouldn't cause system to hang...but then again I myself have not used the overvolt feature on Trixx, as I don't have the Sapphire Extreme cards...do they have separate voltage adjustment for the two cards, or is there just one?
 
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What voltage shall I try? I really want to get to 5870 speeds on both cards. A Sapphire 5870 runs at 1.200V, my 5850s are currently at 1.088V

Other 5850's were normally ok with 1.15v to 1.2v ( max iirc )

But I'm not 100% sure about those Sapphire cards, so it's at your own risk.

Plus watch the temps.
 
Voltage 1.100 and 5870 clock. Ran Unigine heaven 3 times. Max temp was 65C on both cards.

My score went up from 1562 to 1716 with average FPS only going up by 6 :( Not really worth the overclock is it.
 
Stock:

FPS:
57.4
Scores:
1447
Min FPS:
24.1
Max FPS:
125.5

OC (905/1200 voltage 1.150)

FPS:
71.1
Scores:
1791
Min FPS:
32.2
Max FPS:
168.6

Pretty impressed with that
 
Trixxx warns me to disable ULPS.. what's this? Also in order to use the framlimiter in MSI Afterburmer I have to have that running aswell as Trixxx, that's not going to cause a problem is it?
 
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