A warning to prospective 7850 owners

[3DVagabond]

You know, I could be limited by my temperatures right now. I will know tomorrow when my Arctic Cooler arrives.

I just would ideally like 1.25v. I realize it's only a tiny bit more voltage, but I think it would be all I would need to hit 1250mhz or so.

The place where I bought the 7850 from wants me to pay a 15% restocking fee plus shipping across the continent, so it's looking more and more like I will be stuck with this card.

Hopefully the bios modders and the overclocking software people will be able to make me happy with the card.

Have you tried flashing it with the Asus bios? Or have you read where anyone has successfully done so? Actually, you should try and find out if it uses the same voltage control chip. If it does, and the stock bios isn't write protected, you should be able to do it.

 

[Meaker10]

Yeah my 7870 is a slightly more compact design and I don't think it will have voltage control in software either

 

[SickBeast]

Have you tried flashing it with the Asus bios? Or have you read where anyone has successfully done so? Actually, you should try and find out if it uses the same voltage control chip. If it does, and the stock bios isn't write protected, you should be able to do it.

That makes me *extremely* nervous. I will do that as a last resort. I'm pretty sure it would void my warranty if it failed and I could easily brick the card.

I'm up to 1200mhz on my core by ramping up the stock cooler to 100% fan speed. I'm hoping that the Arctic Cooler will let me hit 1250mhz reliably.

 

[Meaker10]

Meh, they could not tell and would not bother to try.

 

[blastingcap]

That makes me *extremely* nervous. I will do that as a last resort. I'm pretty sure it would void my warranty if it failed and I could easily brick the card.

I'm up to 1200mhz on my core by ramping up the stock cooler to 100% fan speed. I'm hoping that the Arctic Cooler will let me hit 1250mhz reliably.

Even if you could hit 1250 why would it matter to you? With perfect scaling that's still just +4.167%. More likely it will give you less than 4% more fps which won't even be noticeable in most situations.

Even 1150 to 1250 is probably a ~8% gain, again, hard to notice in most situations. It's like going from 45 fps to 48.6 fps.

 

[SickBeast]

Even if you could hit 1250 why would it matter to you? With perfect scaling that's still just +4.167%. More likely it will give you less than 4% more fps which won't even be noticeable in most situations.

Even 1150 to 1250 is probably a ~8% gain, again, hard to notice in most situations. It's like going from 45 fps to 48.6 fps.

Fair enough.

I guess my main beef is that everyone at overclockers.uk got 1200mhz out of their card and there I was stuck at 1150mhz with *awful* temps.

Even my memory is weak at 5600mhz vs 5800mhz+ for everyone else.

 

[SickBeast]

Meh, they could not tell and would not bother to try.

Well, like I said it's a last resort in a few months if no overclocking tools come out. I'd rather mod my current bios.

 

[Don Karnage]

No flash tools available. RBE not supported

 

[SickBeast]

No flash tools available. RBE not supported

Not yet. Someone will do it I'm sure.

 

[3DVagabond]

You know, I could be limited by my temperatures right now. I will know tomorrow when my Arctic Cooler arrives.

I just would ideally like 1.25v. I realize it's only a tiny bit more voltage, but I think it would be all I would need to hit 1250mhz or so.

The place where I bought the 7850 from wants me to pay a 15% restocking fee plus shipping across the continent, so it's looking more and more like I will be stuck with this card.

Hopefully the bios modders and the overclocking software people will be able to make me happy with the card.

I wouldn't be surprised if it's temps. The arctic will also come with sinks for the mem and vrm's as well. 1200MHz would be nice, I would think, and I'd be surprised if you couldn't get there.

 

[blastingcap]

Fair enough.

I guess my main beef is that everyone at overclockers.uk got 1200mhz out of their card and there I was stuck at 1150mhz with *awful* temps.

Even my memory is weak at 5600mhz vs 5800mhz+ for everyone else.

First world problems...

 

[Meaker10]

I'm going to have to settle for 1000/1400 to 1000/1500.

 

[SickBeast]

I'm going to have to settle for 1000/1400 to 1000/1500.

Why so low on the core?

 

[jacktesterson]

Sickbeast,

Im not trying to be a dink, but you've made this point in about 25 threads already.

Its not Powercolors fault either. I've used tons of there cards without issue. They are fine for Stock or a moderate O/C. I honestly think if you took your cooler off and put some Artic Silver 5 on it, then reseat the cooler, it'd knock 4-5 degrees off.

You bought the cheapest 7850 on the market. They make dual fan / 3-5 heatpipe coolers on the more expensive models for a reason.

You bought a single fan card to do a High O/C on. That alone was your first mistake. 1200-1250 is a 40-50% overclock. You honestly can't expect that out of the base single fan model of any card.



EDIT: What is your case cooling like? What is your room temps and humidity like? What do you have for case fans?

I recently upgraded cases to get the big 200mm side fan, and it knocked 3-4 degrees off again.

 

[SickBeast]

I just think it's important to dedicate a thread to this so that others are not manipulated as I was. You can join the herd mentality that persisted at the beginning of this thread if you want. I'm just saying, I had never heard of "A-reference" vs. "B-reference" coolers before and really a 25C temperature differential is a lot. As I'm discovering, it can make a big difference in terms of overclocking.

 

[Meaker10]

Why so low on the core?

Heheheh, just joshing you, it's a mobile card, the 7970M (basically a desktop 7870)

 

[VirtualLarry]

I just think it's important to dedicate a thread to this so that others are not manipulated as I was. You can join the herd mentality that persisted at the beginning of this thread if you want. I'm just saying, I had never heard of "A-reference" vs. "B-reference" coolers before and really a 25C temperature differential is a lot. As I'm discovering, it can make a big difference in terms of overclocking.

So, you choose to purchase the lowest-priced card possible. And found out it wouldn't overclock like its more expensive brethren. But you were "manipulated" into doing so? By what, your wallet? Would you prefer PowerColor charged more money for this card, so that others would not likewise be "manipulated" into choosing it?

In the end, all this proves is, you get what you pay for.

(Happy owner of two Gigabyte GTX460 1GB OC 715Mhz WindForce cards. I intentionally choose to purchase higher-end cards, with dual-fan models. They run relatively cool, and pretty silent. They will clock to 840Mhz on stock voltage.)

 

[jacktesterson]

Buy a $69 5000BTU Air Conditioner, and pump that thing into your case.

problem solved.




Joking aside, what are your room temps like? I keep my man cave around 67-68 all the time.

 

[3DVagabond]

Buy a $69 5000BTU Air Conditioner, and pump that thing into your case.

problem solved.




Joking aside, what are your room temps like? I keep my man cave around 67-68 all the time.

Sub-ambient cooling? It's a bit more complicated than that, but the concept is a good one. :thumbsup:

 

[SickBeast]

Guys I think that my main gripe relates to the way the reviews painted the "reference" cards. I didn't think I needed a beastly cooler when the cards were barely touching 60C even when overclocked. That and the lack of voltage adjustment are unexpected bad news for me.

At the end of the day, I saved $30 by going with Powercolor, then I spent $40 shipped to get better cooling than any of the cards on the market. I lose out on voltage adjustment but it's not that bad really.

As for my case temps, they are pretty good. My "auxilliary" temp reading is usually around 29C.

 

[KingFatty]

Well, here is some info you might be able to use when looking at your card. Apologies as this applies to a 5870, however it looks like the same voltage controller can be used on some more recent cards, like the Nvidia 560.

Even with worst case scenario, here is how easy it is to do a pencil mod on a non-reference bare bones basic 5870 that completely and utterly lacks all voltage control. So, even if your 7850 is in the same worst-case scenario, I bet there is a similar opportunity for "tuning" the voltage using a pencil. The link is Italian, but Chrome does a pretty good job translating. Main point is to show what the voltage controller looks like on the 5870 and where to try looking on your 7850, on the backside of the circuit board, probably near the power connector (you won't have to take off the cooler - see the lower left area highlighted as the zona d'intresse della pencil mod). At the time, people bad-mouthed this 5870 on the reviews about how it couldn't overvolt, so its price dropped and I bought one and used this method:

http://www.hwupgrade.it/forum/showthread.php?t=2187874

As you can see, the voltage controller is quite tiny, about the size of a screw hole and its surrounding grounding metal. This low-priced voltage controller may be marked as uP6213. Anyway, a couple pictures down the italian site shows where to draw a pencil mark between the yellow and green spots. Perhaps there is an identical spot on your card to do the same. I've done this mod on a 5830 with very stable and predictable results, but I also used a volt meter to check the resistance of the pencil lead, then draw a little more, recheck, etc. Note that the picture is really blown up huge, the space to draw is thinner than most no. 2 penci leads and I had to use a mechanical pencil for good control.

Here is another site showing the MSI 560 with the same uP6213 voltage controller:

http://www.techpowerup.com/reviews/MSI/GTX_560_Twin_Frozr_II_OC/4.html

But also note, even with the same voltage controller chip, the 560 was able to implement a very basic driver control for software voltage control. The 560 site explains how even though the chip doesn't speak the common 'language' of chip communication (I2C, see http://en.wikipedia.org/wiki/I%C2%B2C), it still can work based on a limited range VID based API.

So there is still hope, as I bet the 560 shows the natural evolution that video card makers have followed when using this basic chip, where back in the 5870 days you had to use a pencil mod, but with the 560 there is more control.

Remember too that you are a trailblazer by getting such a new card, the software guys still have to catch up and reverse engineer how the heck to get voltage control working for your card, at least I have hope for that.

 

[SickBeast]

Thanks very much for that, King Fatty.

I will take good pics of my card as I dismantle it.

I'm not comfortable pencil modding. At the most I'm gonna get 50-100mhz more out of this card and that's all. It's not worth a pencil mod IMO. I don't even have a volt meter and I'm not comfortable in doing that.

I do hold out hope that my card can be overvolted in software or through the bios in the future, though.

Thanks again for your useful and informative posts.

 

[Jaydip]

SB,why do u need such extreme oc from ur card?Which games need this?

 

[WMD]

I think AMD is being extremely disingenuous in their marketing of the 7000 series. Starting from the 7950 downwards there are no reference designs available to consumers but yet they supply reviews based on reference designs! This means consumers are at the mercy of whatever cost cutting measures AIB partners implement in their design. One of the most common practice is putting an impressive looking cooler on the gpu chip but omitting heat-sinks on the VRM section and using cheap non voltage tweakable voltage regulators in place of the digital ones in the review samples. Result of which is impressive advertised overclocking potential that buyers based a large part of their decision on only to end up disappointed upon receiving the final product which is unlike anything the reviews implied. And all that despite the fact that the 7000 series is most hideously priced series of gpu ever. :thumbsdown:

 

[Zebo]

So you bought cheapest HSF card out there and are surprised about lack of Ocing and noise. Spend an extra $20 bucks next time and get a real cooler or XFX one with dual power and 7870 board. I'm thinking about buying one just to show how it done, on water.