zalman vf900 not good enough for 9800gt?

[hat]

The fan on the stock cooler for my 9800gt was dieing, so I replaced the stock cooler with a zalman vf900. Temps in the FurMark stability test reach over 90c. I touched the heatsink and the fins seemed warm to the touch, but when I touched the heatpipe, I got the bodily reaction that screams "get the f*** away from that" and my hand jerked back automatically. Do I need a better cooler for my 9800gt, so am I just not installing the cooler properly? There is good contact with the base and cooler because of how hot that heatpipe got... temps are around 40c idle, over 90c load...

 

[hat]

no comments? do I need a better cooler? a zalman vf1000 perhaps?

 

[DonInKansas]

a vf900 should be plenty for that card. What TIM you using? How is it installed?

 

[hat]

damn... it hit 105c in furmark

I'm using some silver paste my uncle gave me. it's not AS5, but it's better than the stock thermal gunk that nvidia puts on thier cards. it is installed with the big thumb screws that come with it when you buy it, they are all tightened down as far as they can go.

 

[dadi_oh]

Maybe too much paste?

I have two VF900's installed on 8800GT's Oc to 700MHz on the cores. I am hitting about 58C while folding. Your 9800GT is pretty close to an 8800GT heatwise so there seems to be something wrong here.

I am using MX2 thermal paste on mine. I did have one instance with my 7900GT where I had not tightened down the thumbscrews enough and temps were hitting 80C. Tightened the thumbscrews and dropped to 55C. I think that was with AS5.

So my suggestions:

1) Try tightening the screws a little more and see if it makes a difference. I tighten them in a crosswise pattern to ensure it goes nice and even. e.g. if the screws are numbered 1, 2, 3 ,4 then I would tighten each screw one turn in the following order 1, 3, 4, 2, 1, 3, 2, 4, 1, 3, 4, 2, etc... If you tighten too much on one screw without the others then you will get uneven pressure on the GPU die.

2) Try removing the heatsink, clean off all the TIM and reapply. A tiny drop in the middle of the GPU die is all it takes. It spreads out thin as you apply pressure. And teh bottom of the VF900's is shiny smooth so you will get excellent contact. The thinner the TIM the better your temps.

3) Check the fan speed. Are you plugged into the video card fan header and if so is there fan control running? If you are plugged into a motherboard header then make sure it is running full speed (i.e. no ASUS QFan enabled).


So bottom line is the VF900 should be plenty for that GPU. Something else is going on.

 

[hat]

I am using FurMark xtreme burn in mode and I let it run for a while after I re-applied paste and it seemed to hang around 90c. I am not using too much paste, that's for certian. I have used this same cooler on my 8600gts and gotten very good results with it with the same paste. Better than the stock cooler. The fan power header is plugged into my motherboard and should be running full blast... I'll have to try the screw thing... but it doesn't make sense that I would be getting terrible results now with 3 or 4 tries and I got good results with the 8600gts in 2 tries (the first time the base of the heatsink was way off)

 

[dadi_oh]

I am using FurMark xtreme burn in mode and I let it run for a while after I re-applied paste and it seemed to hang around 90c. I am not using too much paste, that's for certian. I have used this same cooler on my 8600gts and gotten very good results with it with the same paste. Better than the stock cooler. The fan power header is plugged into my motherboard and should be running full blast... I'll have to try the screw thing... but it doesn't make sense that I would be getting terrible results now with 3 or 4 tries and I got good results with the 8600gts in 2 tries (the first time the base of the heatsink was way off)

The 8600GT is quite a bit lower power than the 9800GT I think. But give the criss cross screw thingy a try and let us know.

 

[hat]

F@H only pushes my GPU to about 60c, and the ATiTool scan for artifacts test pushes it to 60c as well, however, FurMark pushes it to 95c. These are the settings I use in furmark:

 

[PCpraiser100]

How much space is there between the cooler and additional PCI peripherals? The VF900 needs a good deal of vertical clearance since it shoots most of the air downward if you own an ATX board. Otherwise, you have a cooler with defective heatpipes.

 

[hat]

there's plenty of space. As said before, F@H pushes my GPU to about 60c, which is about the same as what dadi oh gets, and he's much further north than I am (northeast ohio here). It just seems that FurMark produces rediculous temps. I'll have to test with Crysis later.

 

[newtekie1]

Yes, FurMark is known for producing insane temps. F@H is probably the worst the card will ever see in real life, so if it is fine there, I wouldn't worry about it.

 

[hat]

By running FurMark, I see that my card CAN be pushed to 95c. Future games are going to be more stressful than F@H. I don't want my GPU to go boom playing Crysis 2 or something.

Here's something interesting: the gpu core gets so hot in FurMark, that it actually burned the lettering stamped on the core onto the base of the cooler. My Zalman vf900 now has a backwards "NVIDIA" burned into it.

 

[hat]

Crysis Warhead hasn't taken it above 60c. I had F@H running for hours, when I came home I saw only 63c.

 

[dadi_oh]

Crysis Warhead hasn't taken it above 60c. I had F@H running for hours, when I came home I saw only 63c.

Sounds like you have nothing to worry about then... Unless you feel compelled to look at the spinning fur donut for hours on end

I didn't realize Furmark generated that much heat! I have used it for benching and stability testing but my GTX260 is under water so it doesn't really matter what it does... it still runs at 42C

 

[OnBoard]

F@H only pushes my GPU to about 60c, and the ATiTool scan for artifacts test pushes it to 60c as well, however, FurMark pushes it to 95c. These are the settings I use in furmark:

Hmm, take the xtreme burning and post-processing checkmark off? I heats up plenty on stock settings..

My old 8800GT was with Zalman VF830 and cooled great (cheaper aluminium version of VF900).

 

[hat]

Even with all that unchecked it still produces the same results. furmark is just super intensive.

 

[DonInKansas]

Meh. Screw furmark. By the time Crysis 2 hits, you'll probably want a new vidcard anyways.

 

[OnBoard]

Even with all that unchecked it still produces the same results. furmark is just super intensive.

Hmm, it is intense, but shouldn't go that high (although don't remember my 8800gt results ). Did you screw it TIGHT? When VF900 came there were people that god bad results and others that got good results and the mounting pressure affects greatly on the temps.

I had those earlier ones that had chrome finger screws with springs separate and put them so tight that the springs were flat. Don't take responsibility if something breaks and remember to tighten in a crisscross pattern.

btw, the VF830 had normal screws.

 

[hat]

I decided I was going to re-seat it again today, and when I took it off I took a good look at the thermal paste pattern on the gpu and heatsink base and concluded that it was making piss poor contact. No wonder furmark hit 105c before I stopped it! F@H ran at 72c and above. So I tried the meathod where you put a small blob on the center of the heatsink and let that do the work. Worked like a charm... furmark fluctuates from 71 to 72, I've seen F@H go as high as 61c but right now it's at 51c. I don't expect it to hit even 80c in the summer. I guess I just suck at spreading thermal paste with my finger + sandwich bag

 

[dadi_oh]

I decided I was going to re-seat it again today, and when I took it off I took a good look at the thermal paste pattern on the gpu and heatsink base and concluded that it was making piss poor contact. No wonder furmark hit 105c before I stopped it! F@H ran at 72c and above. So I tried the meathod where you put a small blob on the center of the heatsink and let that do the work. Worked like a charm... furmark fluctuates from 71 to 72, I've seen F@H go as high as 61c but right now it's at 51c. I don't expect it to hit even 80c in the summer. I guess I just suck at spreading thermal paste with my finger + sandwich bag

That's more like it

Those VF900's are great budget GPU sinks. Enjoy your new coolness

 

[OnBoard]

Good that it works now. Core without IHS is smooooooth and VF900 is smoooth, so too much paste is bad. Been using small center blob/line method for years.

Sometimes I go funky and use 5 small blobs, center and all corners. With current GPU footballfield sized core(IHS) that might be only option besides spreading it out

 

[dadi_oh]

Good that it works now. Core without IHS is smooooooth and VF900 is smoooth, so too much paste is bad. Been using small center blob/line method for years.

Sometimes I go funky and use 5 small blobs, center and all corners. With current GPU footballfield sized core(IHS) that might be only option besides spreading it out

The rule is, as little paste as possible... best possible solution is 100% flat metal to 100% flat metal but since that doesn't really exist the TIM just fills the microscopic areas of non-contact.

The problem with pre-spreading teh paste is air pockets. Air is a great insulator and when you spread the paste you introduce little bubbles of air. If you use the "blob" method the TIM spreads and forces the air out ahead of it resulting in no air in the TIM.

The blob in the middle still works with an Integrated Heat Spreader (IHS) by the way. You would be amazed at the spreading force applied once you get the heatsink tightened down. I used the small blob in the middle on my GTX260 IHS when I added my Fuzion GFX2 waterblock and it worked perfectly, spreading my MX2 TIM all the way across the IHS. I get 42C on my core (overclocked to 783 core and 1566 shaders) while folding 24/7

 

[Ahhzz]

Glad you found the issue mate, I was JUST going to post the link to the excellent thread on Thermal Paste for you to re-peruse

 

[OnBoard]

The blob in the middle still works with an Integrated Heat Spreader (IHS) by the way. You would be amazed at the spreading force applied once you get the heatsink tightened down. I used the small blob in the middle on my GTX260 IHS when I added my Fuzion GFX2 waterblock and it worked perfectly, spreading my MX2 TIM all the way across the IHS. I get 42C on my core (overclocked to 783 core and 1566 shaders) while folding 24/7

Oh nice, good to know. Though if I go with Accelero Xtreme it has MX2 already applied so I don't need to test it untill I start mounting it again.

ps. MX2 though is quite a lot more liquid than AS5 and spreads more easily