View Full Version : 7900GT: 580MHz is a Safe Overclock?

04-20-06, 01:26 PM
I just got a XFX 7900 GT Extreme, factory overclocked to 520 MHz. I used Coolbits and did "detect optimal frequencies" and it set it to 580 MHz clock/876 MHz memory. :D Seems stable so far, no artifacting; tried 3DMark05, 3DMark06, Guild Wars, and Oblivion.

I've been reading forums and, on one hand, some people brag about volt-modding and running >800MHz (with good cooling I hope!), and on the other hand, people doing modest overclocks and the card dying in a couple weeks. My main question is: Given the apparent stability, is it safe to leave the auto-detected overclock settings? Temperatures (according to nvtemplogger) are 48-51 idle, 71-74 load. My card isn't likely to fry, is it?

04-20-06, 01:42 PM
Those are some high temps. I'd slap an NV5 Rev. 3 on that bad boy, or one of Arctic Cooling's new heatsinks (forget their name, but these are more targeted for the 7xxx series). Though those temps might not *fry* your card, I sure wouldn't run it that high. I try to keep my card (though it is a 6800GT) around 30-35*C Idle and mid to high 40's under load. I'm also using an NV5 to cool it. I would strongly suggest you do the same.

04-20-06, 01:54 PM
I would, but I can't. :( I have a MSI K8N SLI/Platinum that had a really noisy chipset fan, so I replaced it with a Zalman heatsink. This means that I can use absolutely no dual-slot video cards or cooling solutions.

The temps you mentioned are approximately what I had with my BFG 7800GT, very slightly factory-overclocked. The XFX 7900GT, stock overclocked, is only around 5 degrees cooler under load than my extra overclock. Is there any way to keep my 7900GT cooler while keeping it single-slot? Is it only the temperature I have to worry about with the overclock? Thanks!

04-20-06, 02:11 PM
Your temps are fine. Their actually pretty good considering your overclock. 7900's run hotter than 6800's. My 7900 GT, which is vmodded, idle's at 56' C with stock cooling, but with 6 case fans in a cool room. I will, however, be adding some kind of third party cooling solution soon. Again, your temps are fine, don't worry about them.

04-20-06, 10:52 PM
Well, I've heard people say how the 6800s ran hot, but that they were designed to handle it. So I'm assuming it is the same with the 7 series. Regardless, the hotter your card is, the hotter the ambient air in your case is, which means the hotter the rest of your components are. And bottom line, that is hot. Touch the heatsink some time after hours of game play if you don't beleive me. ;)

Here's a cooler that'd work for you:


Which one is right for you you'll need to decide. I believe any of those should fit your card- though you'd be best to double-check.

Also, download RivaTuner. You should be able to adjust your fan speed that way. I'd recommend setting the 3D Performance to run your fan at 100%- that's what I'd do.

I mean, granted, you're card probably wont barbeque itself at those speeds, but what in the world would better cooling hurt? After all, it IS better to be safe than sorry.

I'd never let ANY video card or processor of mine run that hot- atleast not for very long, regardless of whether it was designed for it or not.

04-21-06, 06:17 AM
If you can run Oblivion with the overclock, you're probably okay.

04-21-06, 07:44 AM
I have my MSI 7900GT (stock clocks 450/1320) overclocked to 570/900 and the tempratures are 50 C idle and 65 C Max Load. I asked about these tempratures on [H] forum and they say that those are high for a 7900GT since it is 90 nm process and cannot handle that much heat. They have thus far also advised against the voltmod unless I get a better cooling solution :(.

I would say 65 C should be absolute maximum considering A64 90 nms are rated for 65 C or under for optimal performance.

Overall, I would say back it down to 550/850 and call it a day, like I have :p.

04-21-06, 08:49 AM
Using NvTempLogger (great program), I've fleshed out the problem a bit. I would assume that the important thing is the maximum temperature, not the average (although it raises by about the same amount after overclocking). Logging the temperatures during 3DMark06, I come up with these results (note that 520/1500 is stock XFX for this card):

Max Temp Average Temp (not including CPU tests)
7900GT @520\1500: 69 62
7900GT @550\1500: 71 63
7900GT @580\1752: 72 65

7800GT @425\1050: 65 54

(For comparison, I put in temps from my old 7800GT doing Oblivion, which is more stressful than 3DMark06; at 580, the 7900GT has surpassed 76 degrees in Oblivion! Average temps are approximate; I didn't know exactly where to cut in order to leave out the CPU tests, and there is going to be a different, albeit small, amount of idle temps before and after the benchmark.)

Note that the difference is only 3 degrees between stock-overclocked and manual-overclocked.

This is in a Lian-Li PC-65 with 4 80mm case fans (Vantec Stealth), so I wouldn't think case airflow would be a problem, but I'm still new at this. Does this mean that, even out of the box, the XFX 7900GT Extreme is at a dangerously high temperature? If so, is it a faulty fan, or are my case temps (around 32 idle) that bad? :confused: I shouldn't need an aftermarket cooler at stock speeds.

(I hope SLippe and OWA are right and I'm worrying for nothing...)

04-21-06, 01:37 PM
Good rule of thumb: if it is so hot you can't touch it with your hand- then you have a heating issue. Odds are you wont get 3rd degree burns by touching your heatsink after hours upon hours of Oblivion- but it'll still be rather hot regardless.

If I were in your shoes, I'd purchase some better cooling for the card. The NV5 has done miracles with my 6800GT (which was supposed to "run hot" also). I've got my 6800GT @ 405/1.19 right now and the card never even makes it to 50*C. I'm sure the NV5 would do the same for your card. And yes, it IS compatible with your card. Just so long as you get the Rev.3

But, as you mention dual slot cooling is out for you, try one of Zalman's coolers- I only hear people ranting and raving about how awesome they are. I don't like them because they don't exhuast the air out the back of your case such as the NV series do- but they should still do better than the stock cooling none the less.

04-21-06, 01:45 PM
If you think about how hot the ATI X1900XT cards get, those temps aren't bad at all.

04-21-06, 03:40 PM
Or the Prescotts under full load. But regardless, I always recommend that you do your best to keep it under 55*C full load. My A64 3700 never breaches 50*C except for a rare occasion (hot day or what not) and the vcard never breaches 45*C- even after hours upon hours of rigorous gaming in QuakeIV, FarCry, HL2, etc, etc, etc. And that is with the graphics maxed as high as my card will allow (for QuakeIV I'm running 1600x1200 w/ 2xQ AA/16xAF, vsync enabled and everything else set to high). And both my vcard and cpu are oc'ed- the cpu is oc'd to 2.6 from 2.4 (mobo limited) and the 6800GT is running at 405/1.19. For my setup, it is stretched to its limit almost performance wise yet I don't fear it dying on me cause I know that I've done my part to keep it cool enough to prolong my components lives.

Heck, with any component- oc'ing it to its limit with stock cooling is never the best idea. Oc it to a stable level where temperatures aren't too high, save up and buy whatever aftermarket cooler fits your needs best.

Seriously try downloading RivaTuner- you should be able to adjust your fan speeds within RivaTuner. Odds are your fan is not running at 100% when under full load- so crank it up there. And no, it wont be too much louder than it already is. So don't worry about noise. That should help bring the temp down some, probably about 5*C or so- but it is better than nothing.

04-21-06, 07:47 PM
Just got word back from XFX tech support. Turns out the optimists were right after all. :) The tech said that the card is rated to operate around 75-85*C, and I should only really begin to worry over 85; 76 is the most I was getting at 580/1752 (the Coolbits overclock). That said, I will still look into the Zalman VF-900CU when I have more money; just because it can stand the heat doesn't mean that it won't appreciate being cooler. (Not to mention then I might be able to overclock it more. ;) )

After a bit of research, I downloaded (ironically) ATItool, and found that the 580/1752 was producing a lot of artifacts. (Odd, as none were obvious in actual game playing or 3DMark06; not sure if that's just ATItool being more optimized towards ATI cards or just me not noticing the artifacts elsewhere.) So then I let ATItool determine the proper overclock in its more systematic way. It turns out that Coolbits overdid the core clock but didn't go as far as it could with the memory clock. So for now, I'm sitting at 570/1800. Only 35 3DMarks ('06) away from 580/1752, so I'm happy. Even better, it stayed the same temperature as a more conservative 550/1700 overclock.

04-21-06, 09:04 PM
You have nothing to worry about.

Download RTHDRIBL and run it with your nvcpl open to your temps screen. RTHDRIBL runs in windowed mode so you can watch both at the same time.

Here's a screenshot I just took of my 7900 GT CO Superclocked(TM) at stock 550/790 speeds... (idle temp is 53'C)...

04-21-06, 09:19 PM
Is it just me, or do you like Enya? :)

as for temps. My BFG 6800GT ran idle @56-57c, my eVGA 7900GT idles @ 52-54c. stock speeds.

04-21-06, 11:13 PM
Is it just me, or do you like Enya? :)

as for temps. My BFG 6800GT ran idle @56-57c, my eVGA 7900GT idles @ 52-54c. stock speeds.
Yeah, I like Enya. I just happened to download all those albums from ThePirateBay and I just need to burn them now. (pirate)

Holy crap! I just ran ATI-Tool for just over an hour and my temps got up as high as 95' C! Whoa! I don't know how long it's supposed to take this program to find Max for Core, but over an hour? I aborted and set the clocks to 650/850 (well, 425 in ATI-Tool). I'm uninstalling that crap. :thumbdwn:

04-22-06, 12:00 AM
Well, you guys can go ahead and have space heaters for graphics cards, but I'm not much for it. After all, if you can fork out that kind of cash then $30 to $50 more for a decent aftermarket cooler shouldn't break your bank. Intel also claimed that the Prescotts were supposed to be able to handle thier extremely high temperatures- but we all know how well that went over.

In the worse case scenerio, your card will die sooner than it would with better cooling. Even at those temps though, you should still be able to get a good three years out of the card without worry though.

04-22-06, 11:54 AM
Yeah, ATI Tool really loads the GPU. For every card i've tried it on the temperature went well above what the card was at in any game. So it's irrelevant, as you'll never see those temperature outside ATI Tool.

Speaking of which, it detects very nasty artefacts caused by my memory when it's at 900 Mhz, but i've benched and played with it and there is no artifact in site. Could it be wrong?

04-22-06, 01:09 PM
Yeah, ATI Tool really loads the GPU. For every card i've tried it on the temperature went well above what the card was at in any game. So it's irrelevant, as you'll never see those temperature outside ATI Tool.

Speaking of which, it detects very nasty artefacts caused by my memory when it's at 900 Mhz, but i've benched and played with it and there is no artifact in site. Could it be wrong?

If ATItool finds an error its very real.

04-22-06, 01:32 PM
So, how come their not visible in games and benchmarking, even after running them for some time?

04-24-06, 12:49 AM
How long does it normally take ATITool to find the Max for Core and Memory? I got tired of waiting for it when it reached over an hour. I've since uninstalled it, but just wondering.

10-03-08, 05:31 AM
My 7900GT has a idle load temp at 63 C.... and ive seen as high as 115 C when playing COD4 :S And im having problems with lag in the game, fps drops to 10-15 :S

I guess its fryed ? or just need much much more cooling ?