Powercolor 7870 Tahiti running really hot

dboy

Limp Gawd
Joined
Mar 24, 2003
Messages
189
Been swapping some video cards around for kicks. I got a brand new Powercolor 7870 2gb Tahiti EZ (this one) and put it in my machine.

Nothing currently overclocked, just running bitcoin mining on it to test it out. It's currently sitting at 975mhz (stock boost mode), but 90 degrees with the fan kicked up to 80+%!

I tried the bios update here (http://hardforum.com/showthread.php?t=1750373) to go from the 031 to 032. Not any better, although it does actually go to 975 mhz now. Before it wasn't boosting.

Before this, in the same case and everything, I had a 7870 2gb card from Gigabyte with 3 fans on it, plus a 7850 xfx dual-fan card in crossfire (and no empty slots between them). Running mining on both, and the 7850 OC'd, temps stayed under 75 on both cards.

Is something wrong with the new Tahiti card, or is the single fan really that bad at cooling? My case has minimal airflow, but that's never been a problem before (as said above, even with dual cards). There's no other fans than on the CPU, GPU, and PSU, but the entire top of the case is mesh so heat rises out pretty easily without needing extra exhaust.
 
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Oh, and with mining running, I'm getting some artifacting on the screen as well. Nothing overclocked, but certainly hot! Been running at 97% load for 10 minutes now, and it's at 91C with 84% fan speed. It's LOUD!. Think it's time to shut this down before my wife gets mad at the noise.
 
For some extra testing, I've now got it running underclocked to 750mhz. Temp is stabilized at 85C with 50% fan.
 
Could you please provide a picture of your setup so we know how the ventilation looks like in your case? It sounds like TIM was poorly applied on the die and is not making full contact with the heatsink. I'm a sucker for low temperatures, and usually take apart my cards and re-apply Arctic Silver Ceramique on the and usually see like 20C drop in temperatures.
 
when I was using the stock cooler, absolute peak temp was mid 70's.

This.

My 7950's are the DD versions and they are basically sandwiched. The poor card at the top hits 85 to 90C during gaming while the bottm one gets 70c.
 
Here's some pics.... first is my case. As you can see, the card's alone with tons of room. There's a fan at the top back exhausting, plus the entire top of the case is mesh.


IMG_20130321_192718 by mostlytechnic, on Flickr

I swapped cards and put back in my pitcairn Gigabyte 7870 3 fan factory OCd card. It's now running in the same case, same setup, at just 64C even overclocked beyond the factory OC. It's at 1200mhz right now and I can just barely hear the fans.


Given that, I took a look at the powercolor card. Here's a photo...


IMG_20130321_194719 by mostlytechnic, on Flickr

The part where I drew the red line - how much of that should have TIM on it? When I hold it up to the light, there's only about the center 1/3 to half covered horizontally. I can't see what the vertical coverage is. But on the rest, I can see light through it.

Assuming that's the problem - how much hassle to remove the cooler? I haven't taken off a video card cooler since probably 2004. There appears to be 4 spring-loaded screws on the back of the card as the only thing holding the cooler on. If I take those out, can I just pull the HSF off, clean everything, add some arctic silver, and put it back together? Or is this worth returning the card to powercolor or newegg?
 
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Those four screws will remove the entire hs/f. Pretty simple but return is your call.
 
The Myst runs hot. I have two and the inside card will reach 90C after a few minutes of Furmark. If you don't have a side fan on your case I'd recommend adding one.

The cooler comes off easily. I replaced the TIM on mine and it saved about 5 degrees. Here's what it looks like off.

cardandheatsink.jpg


For bitmining I'd recommend the Sapphire which has a better cooler. Also, you can use Afterburner to set up a custom fan profile so it doesn't run at 85%.
 
Alrighty - took it apart. The goop was on the whole core, but it was VERY VERY thick. Definitely more than yours shown there. Cleaned it off, put on some arctic, and we'll see how it goes. Worst case, return it, but hopefully this helps.
 
It'll still run hot, but you can try lowering the fan to 60%. It'll be tolerable and actually won't increase temps all that much.
 
It'll still run hot, but you can try lowering the fan to 60%. It'll be tolerable and actually won't increase temps all that much.

Um, did you actually READ the problem? I'm hitting 90+ degrees. turning the fan down is not going to help!

Anyway, by the time I got the tahiti back together last night it was late, so I haven't tried it with the new thermal compound yet. I'll do that this afternoon and hopefully it's better.
 
Okie dokie... plugged the card back in (with the new arctic silver in there) and it shot to over 90C in 60 seconds under load. Not at all acceptable... and it was still climbing when I quit it.

Time to contact newegg I guess....
 
I have not had good luck with the Powercolor 7970 either, I just sent mine back to newegg for RMA because it was defective. Wouldn't work at all.
 
I was kind of afraid of that. If you look closely at the Myst the fan shroud extends all the way to the back of the card venting hot air outside the case. The EZ uses the fan shroud from the standard 7870 (not sure why) which doesn't extend to the back of the card, so hot air recirculates.

Here's one Myst running Furmark.

mystfurmark.jpg


That's about 8 minutes. It's 87, which is not good, but this is the inside card of a Crossfire setup in an mATX case. It doesn't run that hot by itself. Also, it's clocked at 1145.

You should probably return it and get the Sapphire, or wait for the Sapphire to be on sale. I'd return it as defective.

I don't think the even the Myst is ideal for bitmining. I wish someone who has the Sapphire would chime in with temps, I'm guessing it runs cooler but don't know.
 
while i don't have issues with heat here.... is it normal for these myst cards to constantly switch core speeds?

i have my core set at 1165 and i constantly seeing it run at that speed or 925. Like, it switches every 10 seconds, then 5 seconds, and then just stays at 925 after awhile while switching to 1165 every 20 seconds but then going back to 925 after a second or two.

Is this normal? It's running at 73c which should still be ok but i don't get this core speed changes...
 
Gotta update to the 32 bios to fix it. Available for download in another thread in this section.
 
tried the new bios and i still jump all over the place. See, the op has a nice clean straight line with GPU clock while running furmark and a straight line for GPU usage as well. I am all over the place with the 28 and 32 bios.....

and it's not just furmark. I ran heaven and then i looked at the graph..... every second or two it was changing the core clock...
 
Are you using Afterburner? You have power limit at +20? Usage always 100%? Try changing the core speed to something else, like 1145 and see if the problem goes away for a while.
 
Seems super hot. Maybe there is a software glitch/error on reading the heat sensor correctly.
 
Are you using Afterburner? You have power limit at +20? Usage always 100%? Try changing the core speed to something else, like 1145 and see if the problem goes away for a while.

i am using after burner. yes i have it at +20. it doesn't switch core speeds as much but it still does it. I even ran it at 975 and it would still switch between 975 and 925 and sometimes even 500... I don't get why at all. Also, when i do try to OC it, when running heaven, i noticed that it only runs at 1100 maybe 40% of the benchmark.. and 925 for the rest...

See, i thought it was a heat issue but it still happens when i just set the fan to manual and crank the fan at 100% (the thing is LOUD!!!).
 
If you don't have another PSU to try, RMA it. Throttling seems to be fixed for everyone else using the 032 BIOS.
 
I run 2 of these in xfire and they will hit 83C in bioshock infinite. I have good airflow in my case.
Clocks in sig with powertune at 15%.
I will probably try reapplying the TIM since reflashing the bios voided my warranty anyway. :rolleyes:
Mine perform excellently, but yea very very hot and loud.
 
I have a myst and the EZ version with the plastic shroud. My myst overclocks a bit higher with slightly less temp on core compared to the EZ. But we're only talking 50 mhz and 3 degree C difference. Nothing major.

The ops card needs more ventilation ideally with a side fan pushing air onto the card.
 
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