How to overclock a 7850 past 1050MHz?

[555BUK]

I have just built a new system for a friend who wants me to get the max out of it. So far I have his 2500K @ 4.6GHz, but I am struggling to bypass the 1050MHz CCC limitation/bios for his 7850.

Even after removing CCC and enabling unofficial overclocking within the latest Afterburner Beta's I cannot raise the slider above 1050MHz. Card is a reference VTX 7850 which is perfectly stable at 1050core/5800mem, but I know that core can do more.

Any tips?

oh, and having played with the 7850 for a few hours I think it is a very decent card. When overclocked, it performs pretty close to my old GTX580 within most games. Even BF3 is playable at 1920x1200 on decent'ish settings. The 580 is better, but not by much.

edit: RESOLVED - See post #11 onwards for MONSTER 7850 overclocks (upto and beyhond 1275MHz GPU / 6000MHz mem stable).

GTX580 & 7950 performance has never been cheaper.

BF3 FRAPS test

Crossfire tests added 27/5/2012

another edit:
NOW 1350MHz Core Stable and benchable @ 1376-1400MHz!

The above requires a BIOS flash to unlock 1.3v (Instructions here). You also need very good cooling (I fitted an Accelero Twin Turbo II). Here and here are some benches @ 1376MHz core.

 

[555BUK]

Well, I still cannot get past the 1050MHz lock, but ASUS GPU Tweak allows voltage control and I can undervolt down to 0.99v and still maintain 1050MHz with complete stability. I think this card will do 1200MHz+, once software (Afterburner/Trixx) fully supports it.

AB b15 just locks up as soon as I open it.

 

[555BUK]

SUCCESS!

To overclock 7850's past 1050MHz you need ASUS GPU Tool (works with any manufacturer).

After install, go into Settings and tick the following boxes.
*GPU Voltage
*Overclocking range enhancement

GPU tool now opens up the clock ranges for my reference 7850 up to 1720MHz GPU and 9600MHz. Needless to say, don't try that high.

Here is a a piccy and Heaven bench at 1200MHz GPU / 5800MHz mem (2500K porcessor @ stock). This provides roughly stock 7950 performance for half of the price.

1200MHz is not the limit, just the first >1050MHz bench I have attempted.

 

[555BUK]

Now running 1250/5800. Needs 1290MHz to reach the magic 50% overclock.

 

[555BUK]

Looks like 1260/6000 is the max for me on stock cooling. 1290 fails on test 2-3 of Heaven, and I do not want to raise volts above 1.15v. At 1.15v 1260MHz is stable enough to loop Heaven.

Still, not bad for a GTX580/7950 matching £170 graphics card. A mere ~45% overclock just does not sound as good as 50% would.

 

[555BUK]

Okay, 1290MHz is stable @ 1.2v. Maybe I should start a new ">50% GPU overclock club thread".

Here's the P score. Note that my CPU is only a 2500K @ stock, and my mobo is a crappy H61.

 

[555BUK]

Here you go guys. 7024 P Score 1325MHz / 6000MHz @ 1.215v. That's a 54% overclock on the reference air cooler. With a decent CPU/mobo I may have gained a few more points, but as this is currently the fastest 7850 on Futuremark, I am content.

These cards are frecking awesome overclockers. Probably the best GPU headroom ever.

 

[555BUK]

P7296 @ 1290/5800 @ 1.225V. 50% OC on air. CPU @ 4.2GHz.

Good score. I need a mobo that can overclock. My graphics score is a tiny bit higher than yours but my CP @ stock lets me down. We're beating stock 7950's for half the price.

Two of these in crossfire would absolutely murder a 7970 or GTX680 for less money.

 

[555BUK]

Yeah i'm only ahead because of CPU score. That OC on your card is mad I don't think mine has that much in it, i've already had to use a tad more volts than you for 1290.

Time to see if 6000mem works

1325MHz is good for 3DMark11 but will not complete Heaven. The highest my card will complete Heaven at is 1300MHz, but that is obviously not a 24/7 clock.

I think safe 24/7 clocks for my card will be 1200/6000 @ 1.125v. Safe benching is likely to be 1250-1275/6000. For the odd pants-down run, 1300-1325/6200 is just about possible, but I do not pretend that will be stable.

I think most reference cards should do 1200MHz easy with a little voltage bump. Two of these cards in crossfure will be a good 30-40% faster than a 7970 clocked at the same speeds.

I cannot remember any card from either side ever clocking as well as these do. No wonder AMD has tried to restrict overclocking these to just 1050MHz. Sales of 6950's, 6970's 7870's and maybe even 7950's will slump if people ever find out. Anyone buying these cards should probably download ASUS's GPU Tweak tool quick before someone at AMD makes them "fix" it.

edit: Just read some more of the release reviews and it seems clock for clock these are only 6-10% slower than the 7870's which cost 40% more. As the 7870's no longer overclock better, 7850's are where the smart money goes.

 

[555BUK]

Extremely tempted by a 7850. 555BUK what is your Stable 24/7 7850 at? What scores do you get with Unigine 2.5 with the stable Overclock not the benching ones ?

I have been testing exactly this for the past hour. It seems that 1200MHz core / 5800MHz mem @ 1.125v will be my 24/7 clocks. This offers the best balance of performance vs heat, power and noise. The card can do 1275 / 6000 stable, but it takes 1.2v to do that and things start getting too hot for the reference cooler without cranking the fan up to unbearable levels. Perhaps the Sapphire or MSI Frozr coolers could handle it quietly but mine cannot.

So, 24/7 = 1200 / 5800 @ 1.125v (just 0.05v above stock). At this speed Heaven benches 57fps, and scores 1435 @ 1080P 4xAA, 4xAF, Tesselation=Normal.

Why dont the 7870's no longer overclock better?

Before the ASUS GPU Tweak tool was available, 7850's could not overclock past 1050MHz (CCC & BIOS limits), but 7870's were allowed to go up to 1300 (if the GPU's could reach it). Now the 7850's can go just as high as the 7870's, meaning the 7870's no longer overclock better. The only performance difference between the cards is that the 7850 has 20% fewer shaders.

Like with the 6850 vs 6870 and 7950 vs 7970, shader counts alone do not majorly affect performance. Clock speeds, ROP's, Memory bandwisth etc mean that a few missing shaders make little real difference.

Many reviewa show a 7850 overclocked to 1050MHz equalling a stock 7870 @ 1000MHz. That mean clock for clock a 7870 is only very slightly faster.

Stock speeds
Stock 7870 = 1000/4800
Stock 7850 = 860/4800
difference = ~20%

before GPU Tweak allowed unlocking average overclocks
OC 7870 = ~1250/5600
OC 7850 = ~1050/5600
difference = ~25%

with GPU Tweak unlocked overclocks
OC 7870 = ~1250/5600
OC 7850 = ~1250/5600
difference = 6-8%

It is not that 7870 no longer overclocks better, it is more that 7850 now overclock just as well. The 7870 is not worth 40% more money for just 6-8% performance.

Which cards is everyone using for these overclocks?

I have a bog standard VTX/Powercolor reference card like this. I paid £169 for mine.

 

[555BUK]

My 24/7 clocks (1200/5800) 3DMark11 P Score of 6621 comfortably beats my old GTX580 P Score of 5356. With the GTX580 overclocked to it's absolute unstable max (930MHz core / 4400mem), it still only scored 6989. I have already posted 7850 max overclocked scores above 7000 above, so this cheap card can kick it in the big league.

GTX 580 @ stock vs 7850 @ 24/7 1200/5800 comparison. The 7850 is a fair bit faster.

 

[555BUK]

What temps you getting at max overclocks and are you setting manual fan speeds, if not does fan get loud.

Late 70's for 24/7 clocks on auto fan setting. The fan really is conservative on reference 7850's, keeping things very quiet.

This card is actually part of a system being built for a mate. I generally prefer NVidia, but this has been the best overclocking fun I have had in many years. No driver issues with it so far (1.5 days and counting).

edit: After playing BF3 on Ultra, temps rose above 80. Looks like I need to create a custom fan profile to maintain 1200 core at sub 80 degrees on a reference cooler.

 

[555BUK]

555BUK you recommend a 7850 then?

Seiously, the 7850 is the best bang AMD card since the 5850. It is probably also the best overclocking card ever. Even though I generally prefer NVidia, I can see this is an exteremely good card which will play anything at 1080/1200P once overclocked a bit. Even with the 1050MHz limitation it was much better than I expected. At 1200-1300MHz it is pretty awesome. The 680 in my main system is faster, but I'm damned if I can notice much different at 1200P whilst playing real games.

IMHO, the 7850 is the best value gaming card available today. Fast enough at stock, cool, quiet, almost reasonably priced, and overclocks like a champ. If it didn't have an AMD label on it, I would get one or two for myself.

 

[555BUK]

Can you go on BF3 for me? with the stable overclock ? at 1920x1080 - (1200/5800) and tell me the outcome please?

I'll try and load BF3 up later. This is a new system build, so not much on it other than Heaven, 3DMark and a few games (F1 2011, Supreme Commander, Metro) so far.

 

[555BUK]

Okay, just loaded up BF3 and played BF3 for 20mins on Ultra with High FSAA. With VSync on framerates stayed mostly at 60fps (indoor and outdoor), with occasional dips into the 50's. FSAA us definatly much better than MSAA, which takes a noticeable hit, and drags fps down to mid 40's in outdoor scenes. This was at 1920x1200, so 1080P should hold 60fps very well with FXAA (post processing) enabled instead of MSAA (I see very little difference between them).

One thing I did notice was that after 20mins my temps had reched 82degrees. I think need to add a custom fan profile.

So, don't expect 60fps all of the timewith this card, but it gets pretty close and if you are willing to turn a couple of settings down it will be great at 1200MHz core.

 

[555BUK]

Can you try it with a new fan profile ?

This profile keeps the temps in the mid 70's, but it is not silent, and I do not like the way GPU Tweak has steps, rather than a gradual hill to bump up the fan. Unlike Afterburner, you can notice the fan ramping up once it gets above 45%.

My 7850 is installed within an ITX Sugo case so airflow is poor. Auto cooling may be perfectly fine for most ATX and MATX cases. I am very picky about noise and heat.

 

[555BUK]

7850 is defo the sub £200 card to get. At stock the 6970 is 5-10% faster, but the 7850 overclocks by >40% and you'll be lucky to get 10% more out of the 6970. As this is an overclockers forums, there are very few here who would argue that the 7850 isn't better.

 

[555BUK]

Actually the graphics scores are very similar to the stock gtx 580 scores in your 3dmark compare, the pbysics score and combined score is wbat makes the 7850 score higher. Would be interested in some overclocked 7850 vs some overclocked gtx 570/580 game benches if anyone has them. Great card, but the 7950 id still the overclocking champ due to lower stock clocks.

The 7950 stock clock is 900MHz and not many overclock past 1200MHz with stability. The 7850 stock clock is 860MHz, and the two posted overclocks on here both sail past 1200MHz with complete stability. The 7850 is undoubtably the current overclocking champ in terms of percentage/performance gains. 7850's clock higher from a lower starting point plus require less volts to do so.

 

[555BUK]

Got myne at 1150mhz core, 5600mhz memory, 1.15v, but this is in crossfire, if I try more the computer just turns off. I'll keep trying but ya, maybe the heat between the close cards is causing this.

Ok so highest I can get it to 1165, 5600mhz memory tops, I'll try again when I have some more time .
3DMARK11 P score:
http://3dmark.com/3dm11/3128422;jsessionid=279ungkeq4bv1ddsqgbmfka60

That is a damn good score.

 

[555BUK]

Just to add a little more info.

The reference cooler is very quiet (almost inaudible) on Auto, but once you start cranking the core up past 1050MHz heat becomes an issue and it is best to switch to a custom fan profile.

My custom profile keeps the card relatively quiet at 1200MHz whilst keeping temps below 80. I would say that if you want to go >1200MHz for 24/7 you are better off with a custom Sapphire or MSI cooler. I can bench at 1300MHz but need max volts (1.225v) and fan on 100% (which is very noisy). I think 1150-1200MHz is probably the sweatspot for reference coolers.

My final 24/7 settings are as follows:-

*2D clocks are underclocked and undervolted.