How to overclock a 7850 past 1050MHz?

[555BUK]

..and then she just died

It was fun having the fastest 7850 on the planet for a few days, but now she is dead. It was a strange death, and she certainly wasn't stressed at the time. I foolishly attempted to install the latest GPU Tweak for the second time. The first time I tried installing it I got instant screen freezes when attempting any kind of overclock. I rolled back to 2.0.6 and all was fine. I decided to give it a second go today. Install went okay, but then I opened GPU-Z.

GPU Tweak 2.1.24 + GPU-Z = Black Screen of Death.

Upon reboot, my motherboard refuses to recognise the card (no BIOS prompt) and gets stuck at error 62. I removed the card and can boot via my 2500K's iGPU okay, so I set iGPU to Primary, reinstalled the 7850 and attempted to re-flash the BIOS. BIOS flashes fine (so card is recognised by DOS), but the 7850 just will post a display output.

Also, using iGPU as primary display allows me to get into windows with the 7850 installed. Windows recognised the HD Audio from the card but CCC cannot see it and I get driver error.

It is almost as if the firmware (something other than BIOS) has been corrupted. I have inspected the card and there is absolutely no physical damage. It was not killed by heat or overclocks because it was running stock at the time (I had just installed GPU Tweak and hadn't tweaked yet).

My initial guess is that something with my flashed ASUS TOP BIOS has clashed with my Powercolor reference card, GPU Tweak, and GPU-Z. Some code other than BIOS has been corrupted and my card is no more.

WARNING
Do not flash cards to the ASUS TOP BIOS and use GPU Tweak 2124 with it. Something in this tool seems to have killed my card!

If anyone has any ideas, please post. Now I have to roll back to my EVGA 680.

 

[555BUK]

There must be more than just BIOS that can be read/written from these cards because things like ASIC quality remain the same after flashing. Perhaps there are some non-writable areas within the BIOS that got whacked?

 

[555BUK]

So it's not salvageable at all?

Unlucky

I can flash BIOS's to and from it, but it is not recognised as a primary display card by 3 different mobo. I am pretty sure that it is corrupted BIOS or firmware, but probably unwriteable areas are buggered.

 

[555BUK]

How do I revert back to my HIS7850 Bios?

When I used the method on Page 43, I did save my rom and atiflash called it "Backup.rom" by default.

But when I run "atiflash -p -f backup.rom" I get an error.

I have renamed "backup.rom" to "his7850.rom" and run "atiflash -p -f his7850.rom" but nothing happens.

I'm afraid that my card may meet an early death like 555BUK's.

Maybe you entered the command incorrectly. Should be as follows:-
atiflash -p -f 0 backup.rom

You missed the "0" (zero) within your post.

 

[555BUK]

My card works again! It is not dead, but something very strange happened to it.

I tested within a friends system, who also owns a 7850. When inserted on it's own, his motherboard will not post (same as mine), but when installed in crossfire as the secondary card it works absolutely fine. Corissfue runs flawlessly with expected fps increases and is reported correctly within CCC. However, when the card is used as the primary adapter (montior cables connected and in PCI-E #1), nothing happens.

Conclusion: ASUS GPU Tweak and GPU-Z somehow combined to corrupt my BIOS in a way that has made the card "half-dead". I now need to order a second 7850 so that I can get full use out of the other within an SLI setup.

Atleast I know the hardware is absolutely fine. It's just that the card does not report itself to PC BIOS correctly upon startup.

 

[555BUK]

I tried that and I always get the same message in DOS.

format: atiflash -p <adapter num> <filename>



Basically since flashing I get what can be best described as juddering/tearing at the top of any web page as I scroll through forums. I am trying to eliminate it and have no idea what could be causing it as my SA700 monitor has the latest drivers as does the Logitech G700 mouse.

Do you have Virtu enabled? That caused some weird juddering for me, both with my 7850 and GTX680.

"atiflash -p -f 0 backup.rom" should definately work. What error message do you get?

 

[555BUK]

When you had it in xfire did you reflash the BIOS on your powercolor card? That's what you have to do or use two cards/onboard graphics so you can revive a bad BIOS,also fully clear mb cmos as it could have corrupted that too making gpu detection error ect

I didn't try to reflash whilst in crossfire, but I have flashed the card back and forth many times, trying many BIOS's. I have now ordered another 7850 to play with. Perhaps I can fully revive my old card, but if not I will just use it as a secondary card within a crossfire setup. I personally think that some non-writable area of BIOS or firmware has been corrupted and that is why 4 different mobo's will not recognise it in standalone mode. All mobos simply do not see it at startup, but it can be seen once within Windows or from DOS.

Very, very strange.

 

[555BUK]

Cossfire 7850's are approx 30% faster than a single 7970 according the the few benchmarks I have seen. As costs for both systems are almost identical, and as both crossfire and sli are very reliable nowadays, it certainly makes sense

Specs
Transistors: 2.8bn x2 (5.6bn) vs 4.31bn
Stream Processors: 1024 x2 (2048) vs 2048 - tie
ROP's: 32 x2 (64) vs 32 - 7850 win
Texture Units: 64 x2 (128) vs 128 - tie
Memory: 2GB x2 (duplicated 2GB) vs 3GB - 7970 win
Memory Bus: 256bits x2 (512bits) vs 384bits - 7850 win
Memory Bandwidth: 153.6Gbits x2 (307.2Gbits) vs 264Gbits - 7850 win
Power Consumption Max: 130W x2 (260W) vs 250W - 7970 slight win
Power Consumption Idle: 14W + 3W ZeroCore power (17W) vs 19W - 7850 slight win

There are however several good reasons to opt for a 7970. For multi-monitor setups the extra 1GB DDR5 may eventually come in handy. Also, some mobo's and cases can only handle a single card.

I do think that for the vast majority of people 2x 7850's will be a superior solution to the 7970 and the GTX680.

 

[555BUK]

I think the consensus is that Sapphire and MSI have the best coolers, with HIS being a little behind but better than reference. The HIS cooker has just two small heatpipes and a relatively small heatsink. MSI has 3 small heatpipes and a larger heatsink, whilst Sapphire has two very large heatpipes and an MSI sized heatsink.

I personally would go for a Sapphire non-overclock edition because they are generally good and cheapish to buy.

 

[555BUK]

Hey guys, Ive not really monitored this thread much, but currently i have a 6950, but i want more grunt to be honest. I would get a 2nd card but from what i read the 7850's are great little cards and oc like its going out of fashion.

Would you get a 2nd 6950 or pick up 2 of the iceq 7850's?

A second 6950 will be much cheaper and offer almost the same performance. 6950's can be picked up on the MM for ~£120.

 

[555BUK]

Will cf with two sapphire 7850's oc'd run 3x 24" Dell mons in portrait 3600x1920 with enough grunt on BF3 or should I opt for a future proof setup and go 7950/70 and have the spare slot for the future?

I only ask cos I have a thermalright twin 6 pin GPU psu and it will feed the CF 7850's real nice at the best bang for buck - but the upgrade path means starting again if I get th 7850's...

I doubt that a single 7970 or Crossfired 7850's will play BF3 smoothly on Ultra settings at your resolution. For me, a single 7850 just about held 60fps with a single 1920x1200 monitor on Ultra with FXAA. Even a 7970 will only provide 75fps, so expect to turn the settings down quite a bit. If you are happy with just 30fps, both should be fine.

Out of the two options, crossfired 7850's will be faster, but you will lose the upgrade path later on. However, I guess you could sell both 7850's and buy a 8970 or GTX770 or whatever at the time. As a rough performance guide, 2x7850's = 1.3x 7970's or 1.2x GTX680's.

 

[555BUK]

What clock speeds did you have the 7850 at to maintain 60fps at those settings in BF3?

1200/5800 did a pretty good job of holding 60fps, although there were some occasional dips into the 50's during big explosions.
Please resize image to maximum 1024 pixels wide. Thanks.

 

[555BUK]

Was that with Anisotropic filter and Msaa applied?

I believe 16xAF but no MSAA. I used FXAA = High (Post Processing) instead of MSAA because it provides pretty similar visuals, but at a much lower hit to performance. FXAA = High is supposedly equivelent to 4-8xMSAA (I think closer to 4x in reality).

 

[555BUK]

Looks like I've hut my OC limit. 1250 core / 1450 mem @ 1.22V. Max temp is 65C so I don't dare increase the voltage any more. I think I could push the memory a little further but I've seen hardly any increase in performance by increasing the memory clock.

At first I thought your score was very low, but then I saw you use 8xAA and 16x AF.

The usual settings for Heaven runs are:-
1920x1080
MSAA = 4x
AF = 4x
Tesselation = Normal
All other settings at default.

That should provide ~56fps.

 

[555BUK]

What is your ASIC quality (click green icon in top left corner of GPU-Z).

 

[555BUK]

ASIC is 72,2%. Does that determine the effect of the frequency? :O
It's not that the card doesn't overclock per se, even at stock clocks (860/4800) its only 988 in Heaven, it should be like 100 more than that from what I can tell by looking at all the scores in this thread.

Generally, lower ASIC values require more volts and are poorer overclockers.

Highest ASIC's for 7850's are in the mid 80's, lowest are mid 60's. Your's is in the middle. My card had 84.9% and could easily do 1300MHz+ but it is all luck of the draw.

 

[555BUK]

mine (MSI TFIII) which is currently voltage locked (dont worry I'm workin on it )shows ASIC Quality, 73.9% is that good or bad???

Slap bang in the middle. You'll probably top out between 1150-1200MHz.

Surest way to get a decent ASIC is to order 3 or 4 cards from different places, DSR the lowest and keep the highest.

 

[555BUK]

Well I generally game with headphones, so it really wouldn't be a a big deal. However, I only have it up that high right now so I can try to push the card, see where it can go.

LI removes increases the TDP limit of the board. With LI set to standard (zero) your board is only allowed to pull ~150W. This restricts overclocks and caused throttling during intensive scenes. LI=20 allows more power (I think it is a percentage so 150+ 20% = 180W), so you can overclock further without throttling.

Now, more power equals more heat, so if cooling is not good enough increasing the LI may not really improve performance, because these cards also throttle above 85deg.

 

[555BUK]

Well, I feel like I've finally pushed my XFX card to the limit:

1300/1500 at 1.3v

Nice, welcome to the 1300 club.

Did you flash the BIOS of does XFX BIOS allow 1.3v?

 

[555BUK]

My ASIC is 81.4% but I can only do 1225 @ 1.25v, is that about right or should it be able to go higher?

1225 is a good clock if completely stable. It could be temperatures that are your limiting factor. Even the best ASIC's are restrained by heat.