9800GX2 Modifications - Anyone with experience?

[styx0r]

I'm starting this thread because I own (6) 9800GX2s, 4 EVGA and 2 PNY - and they are all used for folding. As the weather here in Oregon has started to warm up (which is amazing, by the way - we suffer through rain and cloudyness about 75% of the year), so have my rigs.

Because I want to continue overclocking these cards in the spring and summer, and because I've been so dissatisfied with the card's stock cooling configuration, I've decided to see what I can do to improve core temps. If I am successful, I plan on writing a guide for the [H]orde - I know there are lots of 9800GX2s out there that are baking.

I already know that these cards dump a huge amount of heat into the case, so good airflow to the cards intake, and good ventilation for the card's exhaust (primary vents up, out the top of card, secondary vents out the back via the PCI slots) has already been my primary concern.

However, I think that there's lots of room for improvement. There are plenty of threads online saying "If you own a 9800GX2 and it's too hot, watercooling is your only option." I just don't think that's true.

Simply removing the casing and running the card naked allows the exhaust air to escape from the card far more quickly - not to mention that it increases the size of the intake space on both sides of the card.

I've disassembled one card already and checked out the thermal paste situation - it looked awful (this is a PNY card, by the way) - there was SO MUCH excess paste over the GPU that it took multiple applications of thermal paste remover to clean both the GPU and the cooling surface it mates to. I have a feeling there is great room for improvement here, especially on 9800GX2s that have unusually high load temps.

While I am pretty confident that I can improve the cooling situation, I wanted to start this thread to see if anyone else has already tried this and has any information they want to share. Of course, I don't mind voiding my warranty, and you shouldn't either, if you decide you want to remove the shroud / change the thermal paste...

So, anyone?

 

[84gthatch]

I shall follow this thread closely and remember lots of pictures

 

[capreppy]

I currently own 3 (thanks to Kendrak), but am looking at GTX295's as I prefer to get new or used by someone I can trust has taken care of them.

My 3 have broken up into 2 boxen. I can't run 3 on one MoBo as the middle card is just plain hot. I am running mine in a Norco-470. It has ok airflow, but apparently not enough for 3 of them in one case

I am very interested to see what you come up with.

 

[styx0r]

84gthatch - I own a Canon 40D, so there will be plenty of high-res pics =)

capreppy - Yeah, I understand the desire for 295s - the two cards really have a similar build style - I think the 295's cooler is a little bit better, but the overall design appears to be basically the same. I'll be sure to post my results.

Let's face it - these cards just dump heat into the case! If you own one, just put your hand above the PCI slots on the back of your case - with dual 9800GX2s folding on all cores, this section of the case can become too hot to hold your hand on!!!

A case mod I have been considering for a long time now is to either vent this section with a dremel, install small fans in the same location, or simply remove the section entirely...

 

[Kendrak]

When I had mine I had a 120mm fan at the top end of the cards (shoved right up next to the power connectors) and had some small plastic spacers pushed in between. That helped a bunch. Middle card dropped almost 8c by just doing that.

Getting rid of the case is another big one.

 

[styx0r]

When I had mine I had a 120mm fan at the top end of the cards (shoved right up next to the power connectors) and had some small plastic spacers pushed in between. That helped a bunch. Middle card dropped almost 8c by just doing that.

Getting rid of the case is another big one.

Yes, this is what I am currently doing to my rigs. If you have 9800GX2s and have not tried what Kendrak suggests here, you should do so!

I want to improve upon this idea.

 

[osrk]

I agree with styx0r the thermal paste on the 9800 gx2's could be improved. From what I remember it was a very thick almost play dough like paste really slopped on there. I think if you used artic cooling mx2 you could bring the temperatures down 2 or 3 degrees. I never tested it. They're not terribly hard to disassemble just go to slow. You'll need a small screw driver set but you can pick it up at Radio shack for cheap. The SLI connection on the card comes off easily enough if just pulled on and the cables are different lengths so you know which one goes to which port (two SLI cables total).

Good luck. I moved away from those cards due to the high failure rate associated with them and the fact that you'd be FUBAR if the fan ever decided to shit the bed.

 

[Kendrak]

I want to improve upon this idea.

The one thing that comes to mind is to attach a blower fan to the top end of the cards(the reverse of the pic in OP). This will make them crazy long (not a big issue if your folding naked), but you will be blowing extra cool air into them.

 

[styx0r]

The one thing that comes to mind is to attach a blower fan to the top end of the cards(the reverse of the pic in OP). This will make them crazy long (not a big issue if your folding naked), but you will be blowing extra cool air into them.

If you are talking about the side opposite the PCI slots, this won't work with the cooler in its stock form, because the stock fan shroud effectively blocks this side of the card completely. (I should have taken a picture, but you won't be getting any more air into the card here without cutting the plastic housing). You can only intake air via the side cutout holes in the cards.

*snip* Good luck. I moved away from those cards due to the high failure rate associated with them and the fact that you'd be FUBAR if the fan ever decided to shit the bed.

I understand - although I think the high failure rate is connected with the high temps that most 9800GX2s endure. You're right about the fan - I'm sure it is replaceable - if you want to take apart the entire stock cooler, and hack in a new one. That makes me shudder just thinking about it. That said, I have had zero fan issues with these cards, so I'm just keeping my fingers crossed.

 

[osrk]

I understand - although I think the high failure rate is connected with the high temps that most 9800GX2s endure. You're right about the fan - I'm sure it is replaceable - if you want to take apart the entire stock cooler, and hack in a new one. That makes me shudder just thinking about it. That said, I have had zero fan issues with these cards, so I'm just keeping my fingers crossed.

You can get a new fan from eVGA but you practically have to beg them for it. I had one fail on me. Replacing it was easy except for the one bastard screw who's head stripped out requiring some rough handling to extract the fan.

Alternatively the 8800gts and most of the 8800 double slot coolers use the same Delta fan as the 9800 gx2. Though it's kinda tough to find someone who's selling just the heatsink, ebay has one or two people usually selling them. The 9800 gtx's use a higher amp fan I don't know if you could use it.

 

[styx0r]

Thanks for the information! I'll keep that in mind if I ever have to replace one.

 

[84gthatch]

If this helps I shall be butchering my cards as well because good lord they are running hotter then Hades already

 

[Logan321]

How about cutting that space out, and installing a 120mm fan in a shroud on an angle? Should be reasonably quiet...

Or maybe an 80mm instead, if it's too cramped for a 120mm.

 

[sirmonkey1985]

depending on how many you have in a single system you could do something like this..

 

[APOLLO]

^ That's extremely innovative for an air cooling solution but very expensive unless you can find a deal on a bunch of these TR coolers on eBay or a sale somewhere. Also, the space two fans would require just about eliminates the possibility of additional cards. I would not do this for a 9800 GX2 but for a system running one GTX295 it would definitely be worth the expense and effort to try it, especially considering the cost of those cards.

 

[capreppy]

Hmm. That IS pretty interesting. I'm only running two cards per case due to heat constraints, but with better heat dissapation, I might be able to OC better to make up some of the difference. I am looking at GTX295's for futue boxen, but the solution would likely be the same.

 

[styx0r]

I've seen the TR cooler solution - and while I agree that it's great for a single card machine (especially if noise is an issue), it's not a practical solution.

Even if someone gave me free TR coolers, I would be limited to (1) card per machine - there are fans missing from that picture, so it's double wide card, plus two more slots (for the heat sinks) plus fans on either side of that...

There are some great ideas pouring in, and I really appreciate the input!

At this point, my focus is on improving the stock cooler's ability to dissipate heat, because I don't want to a bunch of money on cooling that I could be spending on more D - or the power bill, for that matter.

 

[sirmonkey1985]

agree'd with 2 fans on it.. it will take up to 6 slots.. 2 slots per heatsink and fan plus the card.... but it sure looks cool..

 

[osrk]

I've seen the TR cooler solution - and while I agree that it's great for a single card machine (especially if noise is an issue), it's not a practical solution.

Even if someone gave me free TR coolers, I would be limited to (1) card per machine - there are fans missing from that picture, so it's double wide card, plus two more slots (for the heat sinks) plus fans on either side of that...

There are some great ideas pouring in, and I really appreciate the input!

At this point, my focus is on improving the stock cooler's ability to dissipate heat, because I don't want to a bunch of money on cooling that I could be spending on more D - or the power bill, for that matter.

You're going to be limited then. The biggest way to increase heat transfer is either through a high volumetric flow rate or a bigger temperature driving force (bigger temperature difference between cooling air and hot surface).

What was working well for me with my 4 gts 205's before the RAM shit the bed earlier this week was I bought a small circle fan about 1 ft in diameter and took off the case side and pointed the fan directly at the cards.

 

[84gthatch]

You've inspired me to try some stuff pics inc

 

[crazjayz]

As far as the TR cooler mod goes, if someone could fab a dual copper plat sandwich around the TR that allows it to contact both core, you could potentially use 1 TR cooler per card, instead of two. Thus, if you could mount one in an "up" position and another in a "down" position, that allows 2 cooled GX2s per box.

I'm just throwing this out there. I don't actually own this card.

 

[SazanEyes]

The guys over at Overclock.net seem to be big believers in running the 9800GX2 cards naked. See for example this thread. One of my GX2s is naked because it wouldn't fit in the last slot in the case with the cover on, but I haven't noticed a big difference in temps. I'm probably going to try it with the rest of the cards eventually.

The biggest problem with the GX2 is that it just produces a ton of heat. My GTX 285 generates similar points, but the temp is so much lower I didn't even bother changing the default fan speed. I'm considering selling off my GX2s and replacing them with GTX 260s or something just for lower noise/heat and possibly power requirements.

 

[84gthatch]

The biggest problem with the GX2 is that it just produces a ton of heat. My GTX 285 generates similar points, but the temp is so much lower I didn't even bother changing the default fan speed. I'm considering selling off my GX2s and replacing them with GTX 260s or something just for lower noise/heat and possibly power requirements.

I agree I'm thinking much the same thing I could run 4 260's in one box with such low heat issues that i could oc them a fair bit making up a decent ppd and not have to break the bank on cooling.

 

[84gthatch]

on the gx2 is there a way to tell which card in windows is which board on the card? In reassembly one of the boards is running stone cold at 50c the other spiked dramatically to 105 I figure i didn't do something right on that one can i tell which is which lol?

 

[styx0r]

You don't have complete thermal contact on the hot card. You can tell which GPU is which card with Rivatuner. Riva tuner will show one GPU connected to your monitor, and the other connected to "default monitor" - then look at which GPU is physically connected to your monitor and you can then tell which one needs to be reseated.

Make sure to tighten the screws evenly and completely - and unfortunately, I've found that the stock cooler dosn't make tight contact with the GPU, so you need more than a thin film of thermal paste to get proper transfer. I suspect this is part of the reason these cards run so hot.

In my testbed machine, I have two naked 9800GX2s separated by a single slot, with fresh thermal paste on all 4 GPUs, cooled with the stock air cooler @ 100%, two 120mm front intake fans at a medium speed, and one 120mm exhaust fan which helps pull the heat away from the cards, at the side rear of the machine. Current GPU temps are in the mid 60s C under full load. Ambient temp is in the room is 68 F.

I'm going to continue testing, and post my final results soon, but I can say with confidence that the stock fan in the 9800GX2 can not move enough air to keep up with the cooling block's heat dissipation. Added (forced) airflow through the cooler results in dramatically lower temps. Because it is so hard to force air in, sucking air out the exhaust end of the card appears to be the most practical solution.

 

[84gthatch]

ya thats a good idea about the monitor styx I should have thought of it lol ya the one side is running dead ice cold the other one was running like mid 60's with no load at all -_-

Thanks for the good work man!

 

[84gthatch]

Ok finally had time to re-grease my gx2 lol and under full load both cores are running at 68c both running 511's admittedly they are running stock speeds so i can't say how high it will go.

With my forced cooling solution it seems to drop the temps about 5-10c i'll put some pics up when i'm done.