How to overclock a 7850 past 1050MHz?

[555BUK]

I can't see the option with a quick scan of the tool.

Found it, still no luck though. Locked at 1050 core, 5800 mem max

You need to click one of the 3 buttons in the bottom left hand corner of GPU Tweak. I think it may be the middle one, but I am at work and cannot check. This will allow the Overclocking Range Enhancement option.

 

[555BUK]

Is anyone else seeing their voltage fluctuate quite a bit in Asus GPU tweak.

Is it meant to act as a power saver?

Voltages drop when in 2D mode. You should be able to see what voltages are set within 2D/3D by clicking the icon near the top left corner.

 

[555BUK]

My overclocks with CCC installed were significantly lower than without it. I remember strugging to get past 1150MHz until CCC was removed, and then the card went all the way up to 1275MHz stable with fan on 100%.

I think CCC somehow prevents voltage adjustments being applied, because 1150MHz was about all I could get on stock volts without CCC. My card has now gone to it's new owner (it was a new system build for a friend), so I cannot test further.

1200MHz/5800MHz was it's final 24/7 clocks @ 1.15v (CCC removed). New owner has been very very happy with it. His system was built for WoW and BF3, and the upgrade from a 4890 has been huge.

edited to say: My card did not like >1.2v. Even on low clocks >1.2v would cause slow downs. It seems that without CCC overvolt protection cuts in, but with it you cannot adjust voltages correctly. It would be nice if GPU had the slider to get around OVP.

 

[555BUK]

I'm using 2.0.6.0 for GPU Tweak ( Same as 555BUK ) and the drivers are off the disc. I hit apply but the clock stays at 860.

*Edit* Maybe it's the drivers off the disc causing the problems ?

Try hitting Apply, the hit Save, and then click one of the 4 profile buttons which appear briefly velow the Save button. You have probably not saved the profile.


As far as best overclocking cards so far:-
*MSI seems best for average overclocks.
*VTX/Powercolor are hit and miss. Some are very good, some average, some poor. My guess is that these chips are not speed binned and you get plain luck of the draw.
*Sapphiire seem lower than average, but perhaps I have missed a few posts.

 

[555BUK]

So after uninstalling CCC, I fixed most of my problems. It seems CCC was stopping the voltage modifications from being applied, now I can actually overclock properly.

The fun beings now !

This confirms my findings. Best avoid CCC if you want to overclock thes cards.

 

[555BUK]

CAT 12.3 with CCC removed, however, notice a couple of things for me.
2D is disabled in the ASUS tool, then look at GPU-Z, no, it isn't.
Look at the voltage, stock in GPU-Z, but maxed out in the ASUS tool.

Whatever is happening, the ASUS tool isn't working correctly on my Win7 install.

In the bottom left corner of GPU Tweak there are three buttons. Try pushing the one in the middle to unlock the advanced settings that include the 2D clocks and extra overclocking headroom. From your screenie, it does not look checked. If you have backup software such as Acronis, try a fresh install to disprove driver gremlins.

 

[555BUK]

You guys with the great overclocks,
do your cards have the 7850 boards using only one power connector? Just to clear up some rumors that people might only achieve the good overclocks on older cards which still used the 7870 layout with the 2 power connectors.

Mine had one connector and did 1275MHz (1200MHz 24/7 clocks).

 

[555BUK]

Yes, a reason for it is the cooler is cack ! i had one, it went back, like other peoples did.

Yeah, the stock cooler on mine only allowed for benching at 1315Mhz and full stability at 1275MHz.

It's not the size of your cooler, rather GPU quality that counts most, and GPU quality is pot luck. If however you need quieter running and the potential for an extra 10-20MHz, a bigger cooler will help.

Is a custom cooler worth an extra ~£40 (~20%)? I would say no, but others will ague.

 

[555BUK]

Is it possible my monitor will struggle with ths new card?

Monitor is Samsung 940 BW

Not really. If you see problems, it is most likely the card itself or the drivers.

 

[555BUK]

My dabbling with MVP led me to believe that it is pointless. Some games show slight fps benefits, others show losses and some won't even start with MVP enabled. It also seems to work better with NVidia cards than AMD.

Forget about it until the technology improves.

 

[555BUK]

I have another 7850 for the weekend, and I thought I would see what it can do. It is another reference Powercolor/VTX card, but unfortunately does not clock quite so well as my original. Top end for the new card is 1250-5900 (old one managed 1275/6000).

3DMark11 @ 1250/5900 scored P7084
3DMark11 @ 1250/5900 with Virtu MVP scored P9665 - MASSIVE gains.
3DMark11 compare - with/without MVP

Heaven @ 1250/5900

Heaven @ 1250/5900 with Virtu MVP enabled - Nice gains.

Heaven 7850 overclocked scores get pretty close to a stock GTX670, and overclocked+MVP scores comfortable beat a 670 (I know MVP is cheating, but hey).

 

[555BUK]

Virtu MVP is strange, someone posted before 40% gains with it on and I find it unbelievable especially since it didn't give me any gains in Heaven or whilst gaming.

What mobo do you have? You need a Z77 mobo with the Lucid chip onboard to use MVP.

My oiwn findings are that Virtu is good for benchmarks (especially 3DMark), but not much changes during gaming. BF3 and F1 2011 show minor gains but only a few fps. Some older games of mine won't even start when it is enabled.

 

[555BUK]

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]

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?

 

[555BUK]

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]

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

1376MHz / 1500MHz @ 1.3v.

 

[555BUK]

@ 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]

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).

 

[555BUK]

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.

 

[555BUK]

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.

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.

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).