How to overclock a 7850 past 1050MHz?

RevBillyG · 14 May 2012 at 19:23

slice313 said:
Have you tried scrolling down Trixx windows? Voltages have to be there...

I missed that too at first

555BUK · 14 May 2012 at 19:49

So, I installed an Accelero Twin Turbo II on a reference 7850 today...

Furmark @ Stock and @ 1200MHz / 5800MHz @ 1.15v.

Heaven @ 1300MHz / 6000MHz

Heaven @ 1300MHz / 6000MHz with Lucid Virtu MVP enabled

3DMark
3DMark11 @ 1300 / 6000 returns P7466
3DMark11 @ 1300 / 6000 with Lucid Virtu enabled returns P9894
3DMark11 with & without Virtu comparison

Cooling Results @ 1200 / 5800 @ 1.15v

Stock cooler Idle temp = 39deg
Stock cooler Furmark load temp = 105deg (crash after 2-3mins).
Stock cooler during Heaven = 88deg

Accelero Twin Turbo II Idle temp = 24deg
Accelero Twin Turbo II Furmark load temp = 53deg
Accelero Twin Turbo II cooler during Heaven = 44deg

*Same fan profile used for both cards, starting at 27% then rising to 100% @ 80deg. Accelero never goes above 35% fan which is completely silent.

Stable Max Overclocks (Furmark)
Reference cooler = 1150MHz @ 1.125v
Accelero Twin Turbo II = 1275 @ 1.2v

Stable Max Overclocks (Gaming)
Reference cooler = 1200MHz @ 1.15v
Accelero Twin Turbo II = 1300 @ 1.225v

Max Benching Overclocks (unstable)
Reference cooler = 1250MHz @ 1.2v
Accelero Twin Turbo II = 1340 @ 1.225v

555BUK · 14 May 2012 at 20:25

glen8 said:
Just unlocked my voltages with the asus bios

Can now loop heaven with 1200 / 1500. That's +50 core increase on my card alone.

Still testing now to see how high it can go.

Do you have a guide for the flash process?

pieman109 · 14 May 2012 at 20:31

555BUK said:
Do you have a guide for the flash process?

I'd like to know that as well but preferably in windows.

Bible Black · 14 May 2012 at 21:21

RevBillyG said:
I missed that too at first

Not only you... now I can change the voltage. :'D

555BUK · 14 May 2012 at 21:52

edit: My card is now dead so probably best not to risk this.

Okay, sussed the bios flash thingy and my Accelero TTII cooled Powercolor 7850 is now unlocked to 1.3v.

You need the following:-
*ASUS DCII TOP BIOS
*Latest ATIFLASH 3.95
*DOS bootable USB stick (research this yourself).

Instructions - DO AT OWN RISK!
1). Copy the ASUS BIOS and ATIFLASH onto your bootable USB stick and rename the ASUS BIOS file to "ASUS7850.ROM"
2). Change you PC BIOS so that it boots from USB stick.
3). Boot to USB Stick
4). At DOS prompt backup your existing BIOS with command "atiflash -s 0 BACKUP.ROM"
5). Flash to ASUS BIOS with command "atiflash -p -f 0 ASUS7850.ROM"
6). Wait 20 seconds or so until you are told that BIOS flash is complete.
7). Restart
8). You will need to reinstall you AMD drivers because your PC sees the new BIOS as a new card.

I have just passed Heaven at 1350MHz core / 1500MHz mem @ 1.275v. Trying for more.....

555BUK · 14 May 2012 at 22:04

Probably the fastest air cooled 7850 in the world with a 60% overclock (for a little while anyway)

1376MHz / 1500MHz @ 1.3v.

teejay73 · 14 May 2012 at 22:05

@ 555BUK, Do we know that 1.3v is safe? I was under the impression that the max safe was 1.25v, What temps are you getting in heaven?

Btw that clock is great!!

555BUK · 14 May 2012 at 22:15

teejay73 said:
@ 555BUK, Do we know that 1.3v is safe? I was under the impression that the max safe was 1.25v, What temps are you getting in heaven?

Btw that clock is great!!

At school I was told that sex wasn't safe. I am glad that I never paid much attention

.

If the cooling is good enough it will PROBABLY be fine.

Here is a 3DMark11 @ 1376/1500. P7751 kills my old GTX580.

555BUK · 14 May 2012 at 22:24

1400MHz is a No-Go. Heaven freezes during tests 2-3 and 3DMark11 dies on the final "Combined Test". Looks like 1376MHz (exactly a 60% overclock) is about my limit for benching. 1325MHz should be 24/7 achievable although I may play safe and back it all the way down to 1300MHz @ 1.25-1.275v

.

..and I didn't even bother to fit the VRM or Ramsinks that came with my Accelero TT II cooler. They are probably useless anyway, and my card is doing well naked.

edit: At 1376MHz core, Heaven pushed the GPU temps up to 47deg.

edit2: For anyone who doubts whether overclocking worthwhile, have a look at the stock vs oc bench below.

Stock speed = 860 / 1200
Oc speed = 1376 /1500
GPU OC = 60%
Mem OC = 25%
Performance Gain = 44% (better than stock 7950 and close to GTX 670 results).

MyUsualOnesUsed · 14 May 2012 at 23:24

Wow! Really impressive overclocks there! I'm tempted to try flashing my one, but I'm not sure the Sapphire cooler would keep it cool while staying quiet at high volts. I also don't want to risk my GPU.

Piklar · 14 May 2012 at 23:25

555BUK said:
1400MHz is a No-Go. Heaven freezes during tests 2-3 and 3DMark11 dies on the final "Combined Test". Looks like 1376MHz (exactly a 60% overclock) is about my limit for benching. 1325MHz should be 24/7 achievable although I may play safe and back it all the way down to 1300MHz @ 1.25-1.275v.

..and I didn't even bother to fit the VRM or Ramsinks that came with my Accelero TT II cooler. They are probably useless anyway, and my card is doing well naked.

edit: At 1376MHz core, Heaven pushed the GPU temps up to 47deg.

edit2: For anyone who doubts whether overclocking worthwhile, have a look at the stock vs oc bench below.

Stock speed = 860 / 1200
Oc speed = 1376 /1500
GPU OC = 60%
Mem OC = 25%
Performance Gain = 44% (better than stock 7950 and close to GTX 670 results).

Top notch work there 555! thanks for sharing your findings, amazing OC and gains of 60%!!, that score you got is very similar to my old crossfire sapphire 5850 extreme score with the cards OCed to 900/1200!! Amazing coming from a humble 7850 :-o

555BUK · 14 May 2012 at 23:32

I fully recomment the Accelero Twin Turbo II cooler. It keeps these cards REALLY cool and REALLY quiet, and is reasonably inexpensive at ~£30. It is certainly MUCH better than any retail 7850 cooler.

I have gained 100MHz and removed the annoying whine than my reference card put out when things got toasty. Idle temps 15 degrees lower than the stock cooler and load temps are less than half (low to mid 40's vs 90's).

Just make sure that you use the black spacers and not the white ones when you install the cooler.

Piklar · 14 May 2012 at 23:33

tuffluck said:
what's all this talk of 5500mhz for VRAM being optimal? the guys on anandtech are saying the same thing, "we've figured out 5500mhz is the best memory OC on the 7850." who the heck figured this out? i've been keeping up with both threads and never saw any conclusive evidence.

FWIW my 3dmark2011 scores rise with memory overclocks. 5800 is higher than 5500, etc.

At least when it comes to gaming with stable memory clocks my findings concur with 5500mhz (1375) being the sweetspot, games Ive tested that have indicated this are BF3, Alien vs preditor,Witcher 2,left 4 Dead 2, Tribes Asend,Portal 2,need4speed shift, CS source, Skyrim.
All games played @5760x1080 (eyefinity) with crossfire hd7850s @1150/1375 @1.168v

Twirlywoos · 14 May 2012 at 23:34

555BUK - What performance do you get in games like BF3 and ALan Wake?

wazza300 · 14 May 2012 at 23:38

555BUK said:
I fully recomment the Accelero Twin Turbo II cooler. It keeps these cards REALLY cool and REALLY quiet, and is reasonably inexpensive at ~£30. It is certainly MUCH better than any retail 7850 cooler.

I have gained 100MHz and removed the annoying whine than my reference card put out when things got toasty. Idle temps 15 degrees lower than the stock cooler and load temps are less than half (low to mid 40's vs 90's).

Just make sure that you use the black spacers and not the white ones when you install the cooler.

doesnt that cooler turn the gpu into a 3slot thickness card? thanks for posting stock clocks its always nice to compare

im thinking of buying the msi tf3 7850 but idk,my 5870 isnt struggling atm but 2gb of ram,less power/temps is tempting me

dave_beast · 14 May 2012 at 23:46

Pretty gobsmacked at what can be achieved with the 7850.

555BUK · 14 May 2012 at 23:58

majnu said:
555BUK - What performance do you get in games like BF3 and ALan Wake?

On Ultra settings BF3 holds onto 60fps pretty well at 1200MHz. I guess 1300MHz will be rock steady but I have tried this yet. I game at 1920x1200, so 1080P should be even better.

wazza300 said:
doesnt that cooler turn the gpu into a 3slot thickness card? thanks for posting stock clocks its always nice to compare

im thinking of buying the msi tf3 7850 but idk,my 5870 isnt struggling atm but 2gb of ram,less power/temps is tempting me

It is indeed a 3-slotter.

Piklar said:
At least when it comes to gaming with stable memory clocks my findings concur with 5500mhz (1375) being the sweetspot, games Ive tested that have indicated this are BF3, Alien vs preditor,Witcher 2,left 4 Dead 2, Tribes Asend,Portal 2,need4speed shift, CS source, Skyrim.
All games played @5760x1080 (eyefinity) with crossfire hd7850s @1150/1375 @1.168v

The best mem clocks on my card seem to be 1450/5800. These are definately faster than 1375/5500 within everything for me. I think that each card varies, and maybe some manufacturers play with the timings (meaning some are okay at 1500 which others choke).

spanielgita · 15 May 2012 at 02:17

Hello, i am amazed at your overclocking results with the 7850 and i will be buying one as part of my new rig.

Would anyone recommend the sapphire 7850? It is £15 cheaper than the msi twin frozer and seems to be similiar.

My only worry is that the software would limit the overclock beyond the set ati ccc limits?

teejay73 · 15 May 2012 at 07:05

555BUK said:
At school I was told that sex wasn't safe. I am glad that I never paid much attention.

If the cooling is good enough it will PROBABLY be fine.

Here is a 3DMark11 @ 1376/1500. P7751 kills my old GTX580.

I was always told to wear two coats to be safe, Hence my reserved nature..