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How to overclock a 7850 past 1050MHz?
- Thread starter 555BUK
- Start date
Yes. Both cards will overclock to similar levels, and clock for clock there is only 5-10 real performance difference between them. Given that the proce difference is ~£40, the 7850 is still the better card.
I also think that the 7870 and 7950 are too closely priced to choose the 7870. There is a much wider performance gap between the 7870 and 7950, but the price difference there is also £40-£50.
So, forget the 7870 unless you can find a real bargain and choose between the 7850 @ ~£150 or a 7950 @ ~£240.
I had a very similar MSI TF that was utter pants as well. My best 7850 out of the four I have owned was the cheapest stock/reference card of the lot (and the one that I used to start this thread).
All of my cards GPU clocks have scaled directly with their ASIC values. >80% great, 70's are okay, 60's pants.
I have happily run a 6850 (very similar power requirements to the 7850) within a Shuttle XPC for the past two years. It's puny 300W supply has also manages to handle a Q9450 processor in tandem with the 127W TDP GPU.
The 6850's and 7850's consume amazingly low power for their performance. I would guess that any reasonable 350W+ PSU could handle one, so long as other components are not power hogs.
One molex plug is more than sufficient to handle the max 75W (6 pin) or 150W (8 pin) load draw from a PCI-E connector, so long as the PSU has the oomph tp deliver the Ampage.
The 6850's and 7850's consume amazingly low power for their performance. I would guess that any reasonable 350W+ PSU could handle one, so long as other components are not power hogs.
One molex plug is more than sufficient to handle the max 75W (6 pin) or 150W (8 pin) load draw from a PCI-E connector, so long as the PSU has the oomph tp deliver the Ampage.
I was talking overclocked performance rather than out of box. Stock GPU clock for the 7850 is 860MHz vs 980MHz for the GTX 660. The GTX 660 also has it's boost mode which takes the core up to 1033MHz and give it a 20% clock speed advantage.
Now, most 7850's will clock easily up to 1150MHz, but the 660 has very little headroom due to voltage limiting and would do well to reach the same 1150MHz within boost mode. My guess is that both cards "real" overclocked performance will be very close, much like when overclocking 7970's and GTX680 to safe limits. It may even be that the 7850 is the slightly faster card, until someone figures out how to unlock GTX 660 BIOS voltages.
Now, most 7850's will clock easily up to 1150MHz, but the 660 has very little headroom due to voltage limiting and would do well to reach the same 1150MHz within boost mode. My guess is that both cards "real" overclocked performance will be very close, much like when overclocking 7970's and GTX680 to safe limits. It may even be that the 7850 is the slightly faster card, until someone figures out how to unlock GTX 660 BIOS voltages.
I use a Corsair HX850W within my main "test system". I have had one 7850 running 1350MHz rock stable on air, another that couldn't reach 1100MHz, and 3 others that reached figiures somewhere between. Memory clocks also ranged from 1325MHz to 1525MHz, and the fastest GPU did not also have the fastest memory.
In my opinion GPU quality is absolutely key. A good GPU will run faster at a given voltage, even if the PSU or other variables hold you back a bit. Unfortunately GPU quality is completely ramdon. My best overclocker was a vanilla Powercolor reference 7850, the worst was the most expensive and best cooled MSI TF4.
I also believe that high ASIC quality increases the chances of a good GPU. My best 7850 was 84%, the worst was 67% (I think). I also have a high ASIC 7870 which performs excellently as well (1325MHz GPU stable, benchable at 1360MHz).
I play with too many toys
.Here. Just select your OS version.
Using Afterburner, I set 30% up until 40deg, then a straight upward slope hitting 100% at 90deg. Card never goes above 65deg during gaming at about 50% fan.What's the best fan profile? Attempted... but didn't go so well, one second the fan would be almost silent, the next sounding like a jet engine (Not really, but quite noisy, i could tolerate it)
So long as temps stay below 80deg, keep the fan as quiet as you like.
If it has only crashed once, don't worry too much about it. It may have just been a driver bug. If it happens again, return the card to stock settings and check for stability.
There are some 1376MHz benches linked at the bottom of my original post - see post #1 of this thread
. There are also benches of it at varying clocks throughout the thread,Here's a 3DMark11 1400MHz bench I prepared earlier. The score is roughtly the same as a 7870 @ 1300MHz or a 7970 at stock. Card was far from stable at 1400MHz but could pass most benchmarks. 1350MHz was stable with an after market Accelero TT cooler.
According to Futiremark my 7850 was rated as 15th fastest for a single card. It may have been my lowly 2500K not being able to hack it against 6GHz 3770's.
edit: The 7850 in question has now moved to it's new owner where it sits within a crossfire setup run at stock speeds
. The current 1360MHz benchable 7870 I am testing will be off to it's new owner next week. If anyone wants some 7870 benches, let me know quick.
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1.2v is completely safe. Most 7870's default voltages are set to 1.218v, and a 7850 is just a 7870 with some of the sahders disabled. 7850's will be completely safe at 1.225v so long as temps stay below 85deg.
Some card have custom vrm's and power management that either does not output temperatures, or cannot yet be read by GPU-Z. Just ensure that you have the latest version installed.
Some 7850's run stock volts of 1.218v. I am sure that 1.225v will be completely safe, and I personally have no reservations runnng 1.3v so long as temps stay below 80deg.
Technically yes (if you go above Catalyst Control Panel limits), but there is no way any manufacturer can prove a card has been overclocked.
Welcome.First time post, first time PC builder, and first time overclocker.
After finally managing to get Afterburner to overclock beyond 1050/1450 (wish I'd found this thread earlier), and finding out flickering isn't an overclocking issue, I'm now starting to experiment.
I have the MSI Power Edition, which had a stock voltage of 1.21mV, and ASIC of 71.9.
Initially, I put the voltage down to 1.1mV for the limited oc of 1050/1450 that I'd been running and that seems to be fine.
I'm testing stability using Sleeping Dogs benchmark and Kombustor. I've kept the mem at 1450 all along as that was the max CCC overdrive allowed so seemed a safe value.
I'm getting 1150/1450 stable at 1.179mV, and 1170/1450 stable at 1.2mV. 1200 definitely not stable at 1.2mV and I think I'd need 1.25mV for that. Max temp is 59 degrees.
So, looks like I don't have a great overclocker. Any tips for improving the clock? For example, would there be any benefit in reducing mem speed?
Also, I have triple voltage control. Do I need to mess with those separately?
Thanks
I suggest not using Kombustor for extended periods because the program it is derived from (Furmark) is a known card killer. I prefer to loop the Heaven benchmark for 20 minutes or so to guage stability.
The cooler on your PE card is pretty good so it will be safe to use max available volts (should be 1.225v). Leave the memory at stock settings, up volts to 1.225v and test how far the GPU can go. Start with 1200MHz and go up or down from there. Once you find an overclock that appears totally stable, subtract 25MHz for safety margin. Once you final GPU overclock is established, up the VRAM. Generally the VRAM will clock somewhere between 1375-1500MHz.
If you end up with final clocks somewhere around 1150MHz core and 1450MHz vram, be happy. Any more will be a bonus.
I have had 7850's that can do 1300MHz+ whilst others struggle to pass 1050MHz on 1.225v. GPU quality is pot luck, so just be thankful you have not got a stinker.
GPU Voltage may be too low at 1150mv. Try 1225mv or reduce the GPU overclock.Tried 55BUKs settings and keep getting this error after about 5-10 seconds of running heaven @ tess-normal x4 AA / Antistropy @ 1920*1080
Is this because i have yet to OC the CPU or have i done something wrong? Im also using his custom fan profile
1GB cards should clock to similar levels as 2GB cards. As far as I know they contain exactly the same components except for 1GB of missing VRAM. If anything, the VRAM on 1GB cards may clock slightly higher (there is less chance of 1 module being poor when you have less modules).
Some GPU's are just better than others. Purer silicon tends to require less volts to obtain a given clock speed. The purest silicon tends to come from the centre of a wafer (a large disc from which many GPU's are printed). Lower quality silicon may come from the outer edges of the same wafer.
Similar tolerances exist within all electrical and mechanical components. Although they are made the same, some are just better. It is the same with light bulbs. Install a set of bulbs connected to the same switch and they will all pop at different times.
AMD appears to measure the quality of it's GPU's by ASIC value. Lower ASIC's tend to require more volts to run at a given clock speed. Higher ASIC's require less volts for the same speeds. Unfortunately the GPU you get is completely random. The same applies to the memory modules and all other components on your graphics card. Some people get very lucky and get great GPU's, great VRAM and a high quality PCB. Others get utter rubbish, whilst most sit in the middle.
With good cooling 7850's can handle 1.225v. Many low ASIC GPU's have default voltage set to 1.218v anyway, so 1.225v is just a tiny fraction above standard for many cards.
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What volts are you running for 1050MHz? I had one very poor chip that could only just manage 1050MHz at 1.225v. Try upping your volts to 1.2v and see how far she goes. The memory should be good for atleast 1375MHz.
Does PES crash when run at stock speeds or just when overclocked? If it only crashed when overclocked you need to add more volts (1.225v) or turn the clocks down.