Worse performance with SLI than without: thermal issues (980 Ti)

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I am not quite sure what to do about this. I recently bought a new 4k monitor (see here for discussion), and I thought that I had better get two 980Ti cards to put in SLI to ensure that performance in 3d applications/games was serviceable given what I had read.

I initially installed just the one card for testing, and this worked reasonably well (average of 34fps on the The Division benchmark with the automatically selected settings, which were mostly at maximum apart from the special NVidia shadow settings and anti-aliasing), but with some room for improvement. I spent some time wondering whether to proceed with SLI because it would mean removing my PCI Creative X-Fi sound card and relying on built-in audio (albeit with the ability to add a PCIe sound card in due course), and eventually decided to do so.

Having installed the second card, however, I find that the temperature of one of the two cards gets so high (often up to 91C) that the clock speed is throttled to circa 500mhz (the default with this particular card, the MSI Gaming 6G is in excess of 1,300mhz), which makes the framerates significantly lower (in The Division, at least) than with a single card, the benchmark recording average framerates in the 20s after a few passes (whilst the card heats up). Playing the game, the framerates are usually reported in the teens. With a single card, they were in the high 20s outdoors and in the 40s indoors.

With a single card, the temperature would reach about 83-84C and the card would be reduced to about 1,100Mhz and remain fairly stable there on the The Division benchmark.

There are only two PCIe 16x slots on my mobherboard, so I have no choice of spacing the cards more widely than they are spaced at present. There is only a tiny gap between the two cards - indeed, I had to use one of the plastic caps that covered the DisplayPort sockets to push the cards apart a little to stop the fan of the no. 1 card rubbing on the backplate of the no. 2 card.

The case is a reasonably decent Antec with sensible provision for airflow: I have added a fan at the front to the existing rear and rear top fans (and replaced those with models that are more efficient and less noisy), and I am not sure what else that I can do about airflow.

Having unpacked the card and install it, I cannot now very well send it back, and I should hate to have to sell the thing secondhand just after having bought it, thus losing a considerable proportion of its value for no sensible gain.

Has anyone any suggestions of what, within reason, and without making my computer sound like a jet engine, might be done about this?

Edit I should add that I tested disabling SLI in the software without physically removing the second card, and the results were worse than with SLI enabled. SLI is definitely working, as both cards report significant GPU usage, although The Division is not as well optimised as it might be for SLI, so usage on one card is greater than on the other.
 

pendragon1

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There is only a tiny gap between the two cards - indeed, I had to use one of the plastic caps that covered the DisplayPort sockets to push the cards apart a little to stop the fan of the no. 1 card rubbing on the backplate of the no. 2 card
The case is a reasonably decent Antec
I'm pretty sure your issue is airflow or lack of to be more precise. which antec case is it? if it is not one of their enthusiast cases it probably does not breath very well. you could try and rig up a fan to blow in between the cards to provide the top with fresh air. or you could leave the side panel off and blow a house fan into the case to see how temps are. if that helps you probably need to replace the case and/or add fans.
 

silent-circuit

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You will probably need to replace the cooling solutions on your cards, or at least on one of them. An AIO watercooler would be best if there are mount points in your case to support one, since this would dump all the heat from the second card outside of the case.

As pendragon1 said, we need to model of the case, to get a better idea of what's going on. "It's good" isn't good enough.

Also, is this an mATX board or something? Very odd to find slots that closely spaced on a full size board.
 

pendragon1

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tran, I just watched a vid about that and was going to post here. you beat me to it! it is a commercial version of what I suggested.
 
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Thank you all very much for your responses: it is much appreciated. As to the details, I thought that the best way of providing those would be in photographic form. I have uploaded various photographs of the case to here.

I cannot now find the model number of the case, but hopefully the photographs will give you the information that you need. The motherboard is a Gigabyte X58A-UD7 from 2010, which was thought of as one of the better enthusiast boards at the time. I did look into upgrading the motherboard and CPU as well, but the impression that I got from such research as I did was that, with the recent breakdown in Moore's Law, plus the fact that the motherboard and CPU (an i7 950, which is overclocked to 4.16Ghz) were reasonably high-end to begin with, it would not be worthwhile. The motherboard has two PCIe 16x slots, two PCIe 8x slots, one PCIe 1x slot and one PCI slot. The PCIe is 2.0 rather than 3.0, but, from what I understand, with current generation cards at least, the difference in performance between the two is modest and not worth upgrading motherboards/CPUs for.

The photographs show the outside and inside of the case, and the inside of the case with both graphics cards, with no graphics card, and with just the one graphics card (which is how it is now running for the time being; I have temporarily removed the second graphics card as it was not helping my performance).

I am very keen on the computer renaming as quiet as possible for general use (which is why I bought this specific case), and only becoming noisier (automatically) when under a heavy 3d load. The case originally came with a rear and top fan that were controlled by mechanical three way switches located at the rear of the case, but only the lowest setting was quiet, and the rear fan had an intermittent fault resulting in it not spinning at all most of the time, so I replaced them with Aerocool fans (as pictured), which are quieter for any given amount of airflow. I connected these to the previously unused motherboard headers in the hope of automatic regulation, as I really do not want the laborious task of changing the speed of my fans manually all the time.

Does this give you all sufficient information to make further suggestions, or is there anything else that you need? Thank you again all very much.
 

silent-circuit

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OK, so reasonably good airflow (I think it's an Antec Performance One or something like that, can't remember the exact model).

Honestly, running dual 980Tis, you should really upgrade the rest of your system. I'm pushing it with a 2500K, you're way way behind the curve with a 950. The biggest problem is the spacing of slots on that board.

The case itself isn't ideal; as you said, it's made more for quiet than cooling performance and you have a lot more wattage in there than was even possible when it was designed and built, but it should be okay. You may need higher CFM / static pressure fans. Sadly that will make it a bit louder.
 
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From my understanding, it rather depends on the application/game as to whether it is more CPU intensive or GPU intensive. Cities:Skylines tends to be more CPU intensive, whereas The Division tends to be more GPU intensive. No doubt, I could get better framerates in The Division with a well cooled SLI setup; the CPU usage is reported in the benchmark as significantly less than the GPU usage.

The front fan that I installed was a high CFM fan, the rear fans not being so; I did not think that a high pressure fan was necessary for exhausting out of the case. What RPM should these fans be running at when things get warm? The autmoatic system tends to run them at 1,200-1,300 when the internal system temperature is circa 55C, which is what it is sensed as when the GPUs are running at 91C.

With just the one graphics card, The Division does run considerably faster than with the both, with much less throttling.
 

pendragon1

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Yup I agree. Either add fans with higher cfm, try and get air to the cards or look at water cooling one or both cards.
 
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SLI is kind of nasty and inconvenient to mess with, and you're seeing first-hand why. That's one reason why I've been telling people to wait for Pascal before getting 4K monitors.

I mean, sure you can get 30FPS in games right now with the 980Ti, but you're having to run a flagship card to get mediocre performance. By itself, it's a power-sucking beast that gets very hot and taxes the heck out of the PCI-E subsystem. You're running two of them.

You absolutely have to have a decent cooling system, and two 980Ti cards are NOT easy to keep cool. Especially with an older CPU that's not very power efficient sucking down power as well in the same cramped space. Watercooling and installing waterblocks is an extreme solution that will pretty much void your warranty, but you would almost have to do that if you keep using your current case AND want to bring the noise down. I would personally get a case with much better airflow, and as many fans as you can get. If you're worried about noise, my opinion is that it's better to just put the computer in one room like an air-conditioned closet or something, and run wires to your monitor, keyboard, and mouse in another room so you don't have to hear it. Depending on your home network setup and a few other variables, you might be able to just use a lower-end system for Steam In-Home streaming and not even need wires.

Another problem I'm seeing is that your system predates PCI-E 3.0... I'm not so sure whether you have a board that can deliver 16x to each card, or whether it's splitting that to 8x... but if it's splitting it, that's each card with about half the bandwidth it would have running in SLI on a newer machine. I would try cooling the cards better first to see if that helps before worrying about this, though.

SLI really works better for low-end cards than it does for high-end cards. Adding a second card later on after the cards are obsolete is often a cost-effective way to improve performance. It's not really a practical way to get the best out of brand new flagship cards, IMO.
 

pendragon1

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yes high cfm. brand idk. corsair sp120 are good. I have a mix of what ever I had on hand. biggest thing is getting fresh air to the cards. only other thing I can suggest, without switching cases or going to water, would be to cut a 140mm vent or two in the side panel right over the cards and put fans there.
 

husker4life

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I had a similar issue when i had 770 SLI the top card would be 10-15C hotter and they were both blowers. The cards would also throttle and the only way to prevent that would run the fans at 100% which sounded like a leaf blower, i also have a similar case like yours (P182) and its built for silence rather than good airflow. Looks like water cooling would help obviously but their is more cost with that. I just have a single 980 ti OCed open air cooler now and it doesn't ever throttle.
 

pendragon1

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oh and also gap out the cards as much as possible. loosen the screws on both cards, tilt the bottom card down are far as possible while still having the screw hold it in place and tilt the top up as far as you can. only use one screw per card, you don't need two. just try and widen the gap so fresh air can get in.
 
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Thank you for all your feedback. I really do not want to do anything too disruptive or extreme - putting the computer in a special air-conditioned room, for example, is beyond what is sensible for my setup. Playing games is not the highest priority for my system, but it would be good to have a means of it working well when I do want to relax with a game.

I had considered carefully whether to wait for Pascal before upgrading, but my previous monitors were old and I needed to cascade them to replace a CRT from 1999 that I was using on a very old computer when I go to visit my parents; I had bought a small NUC for use in that situation and also for use in work. Additionally, I wanted better monitors for photograph editing and work on documents at home, and this was a higher priority than gaming, which is why I opted for SLI, which is less optimal than a single card solution, but appeared to be the best of the various options available to me. At present, it seems as though SLI is actually considerably worse than a single top end card, which I had not expected (and I have removed the second card for the time being to get the better performance).

As to fans, the fan that I have blowing into the case is one of these plugged into the mohterboard's only 4 pin fan socket (reported as "SYS_FAN 2", I believe). The two fans blowing out of the case are these. Am I right in understanding that fans blowing out of the case need not be (and do not benefit from being) high pressure fans? What sort of RPM should the fans be spinning at when the system is hot?

How practical is water cooling these days? I remember a time when it was considered an extreme hack for only the most adventurous of overclockers, but I see that some graphics cards are sold with water cooling as standard now. I decided against those because it would be awkward to fit the radiators inside my case, and putting them inside the case would not help me in any event as the heat would be dissipated inside and not be any better than air cooling, plus, from what I understand, the pumps are noisy, meaning that, when not under load, the noise level would be higher than an air cooled product with fans that do not spin when the card is cool. The cards with built in water cooling all seem to have a sealed system, so there would be no way that I can see of having the radiator mounted outside the case. The case does have two holes for what I assume are water cooling pipes which are visible in one of the pictures, but I do not know how challenging that it is to set up water cooling these days. I am reluctant to go to extreme lengths to get SLI working, but am prepared to give it a go if it is not too hard.
 

Napoleon

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I think you should get a 120, 140, or even 200MM fan mounted to the side, it's time to get your hands dirty and mod your case. Plug these straight into the 4 pin connector, if you're concerned about noise you can get some of the nice fans

I don't know how 'professional' you want this to look, but ducting of an external fan could be helpful for you to make sure the air is surrounding the cards. For your case, whatever it is, remove the unused expansion slot spacers so that you have more airflow. I'm suggesting you use cardboard/tape to help funnel the air around your cards from the fan and then straight out the back. I have no shame in the name of temps, I once duct taped two high-CFM 120mm fans screwed into some 1x1 wood dowels to the side of my comp for OC'ing (back in 2004).

Check the front of your case as well because sometimes there vents that are blocked for aesthetics. You mentioned some pics but I can't see any, could you please post some pics of the case closed and open?

Some other thoughts, it sounds like your cards use the blower-style closed closed heatsinks? Is that true? Swapping for open style might work better, although with no air flow they will still struggle. Looking forward to some pics :)

Also, it is my opinion that you should maximize the passive airflow of the case; if your fans are sucking out air, where is it coming from? I'm a fan (haha pun!) of having fans blow onto the MOBO/CPU/GPU and letting the rest vent through the PSU, top vent fan, and any open vents

Also, these are selling for $60/each right now: EVGA - Products - HYBRID Water Cooler (All in One) for GTX 980 Ti - 400-HY-0996-B1
 
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pendragon1

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here are his pics. he has dual fan cards not blower style. OP you could always use one of those evga coolers to cool one card out the back exhaust. that would help a lot!
 

horrorshow

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Yeah, you're blowing hot air onto your bottom card.

A Corsair SP120 on the side panel would work. Otherwise swap the top vcard cooler with a reference design.
 
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Napoleon - thank you for your reply. The pictures are as Pendragon suggested. I have just been experimenting, playing The Division with one card. With a single card and the case closed, I was getting decent framerates (30s), but it was still thermal throttling slightly. The system was also unstable (I did not notice this before when I tried a single card), and would freeze after about 5-10 minutes playing The Division.

I then tried taking the side of the case off. The card no longer thermally throttled, and there were no crashes. Framerates were fractionally better (perhaps 1-2fps better than with the side on). I shall try shortly the SLI arrangement with the case side off and report back the findings. I also wonder whether the fans are spinning fast enough. I did ask once or twice but do not seem to have had an answer - how fast should my case fans be spinning?

I am not a fan of the idea (no pun intended) of cutting a large hole in the side of my case to put a large fan in it, not least because I doubt that my cutting skills are up to that; also, it would significantly increase the noise when idle, which I do not want. The water cooler idea looks potentially promising - but how would I thread the pipes through the holes in my case shown here? Presumably the radiator would attach to the back of my case somehow...?

Thank you again for all of your thoughts.
 

Napoleon

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Thanks, pendragon1

That is one tight fitting comp! Even if were able to mount fans, I'm not sure how much it would help with that spacing. You might be able to keep it wedged and to put 2x 140MM (or 120MM) fans blowing onto the cards from the side (this would require cutting a whole into the side of your case and mounting. That would require you to reposition your tower as the left side of the computer would need to be open for airflow.

This makes me realize the importance of a large MOBO for any air cooled SLI. Best of luck!
 

pendragon1

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re fan speed; as fast as possible to move the hot air out of the case. but you are going to have to play with the speeds to get a noise level you can live with. try "open hardware monitor" or "speedfan" for controlling your fan speeds.
 
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Thank you both - the Open Hardware Monitor program is very useful.

Results of further testing: in SLI mode, with the case side open, there is a slight improvement on my previous experience with SLI mode with the case side closed, but not much. Initial results appeared promising (especially when setting the fans manually to 100%), but the top card would still heat up to 91C over time and be clocked back very significantly to circa 400mhz. This took longer than before, however, and I was able to run a few passes of the The Division benchmark with a higher average framerate than one card, albeit not by a great deal.

Cities: Skylines does not seem to take advantage of SLI at all, as the bottom card was barely used. The top card was thermally throttled, but only to 1139Mhz, and still returned good framerates (up to 60 in quiet areas, and in the 30s for the most part, when paused, looking around built-up areas).

I tried to play Heroes & Generals, but the computer crashed just as I was starting to play, which it had done earlier in the day with just the one card installed and the case sides on. The temperatures reported for the cards were, I think, although I did not check immediately before the crash, lower than they had been when playing The Division. The crash occurred in a somewhat unusual way, with the computer powering off and then powering on again after about 2 seconds. This game had, I think, worked correctly a few days ago when I had first installed the single card.

Does the fact that it is the top card in particular that is getting hot alter anyone's views on how best to proceed? Would the EVGA water cooler recommended above be a workable solution on the top card? How would the pipes be threaded through the holes in the case?

Thank you again for all your help.

Edit: I tried again with Heroes & Generals, and was able to play without it crashing again. This game seems to make limited use of SLI, but, neverthless, no doubt because it has an older and less damanding graphics engine, I was able to get decent framerates for a while, but, again, the top card eventually reached 91C and caused severe throttling to circa 500Mhz. The lower card, meanwhile, was at 68C.

Edit 2: Are you sure that that water cooler is compatible with my card? The sales information suggests that it is compatible with all reference designs, but I do not think that my cards are reference designs.
 
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silent-circuit

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You really need to find a title other than The Division with known good SLI scaling to test this, so the second card is properly loaded and you get "real world" numbers in terms of how fast the cards are going to heat up.

Try hanging a fan (or two) if you have spares so that it's pulling air out from between the two cards?
 

pendragon1

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If you can rig up a fan to blow right on the sides of the cards that will help. You could also pop the coolers off and apply new thermal paste. It should not void your warranty even if there is a sticker on the screw. They don't care unless you damage the card. I do realize they are new but putting on new paste will be better than the paste from factory.
As far as the evga cooler goes, I'd put the rad where your back exhaust fan is. Then just reuse that fan elsewhere.
 
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Thank you for your replies. Can you recommend a suitable game for SLI testing? I realise that The Division is not fully optimised for SLI, but it does at least work with it to some extent. It is a shame that Skylines does not use SLI at all.

As to the EVGA cooler, will that be compatible with my MSI card, or do I need a special water block as in this video?

In respect of the radiator position, would this fit in the small space between the very large CPU cooler and the rear grille?
 

Dayaks

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You probably could have modded your case for a side fan in the time it took for you to write those paragraphs. Hell, I did it when I was 12 with a drill and a few bits. You can get a fan controller for it.

The other suggestions are perfectly fine too. I personally like those hybrid 980tis that come with an AIO on them or build a custom loop.
 

pendragon1

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Yeah it should fit. Maybe fan on the out side rad inside the case. The ek block is for a full loop. Yes, if you want to you can build a full loop for just your gpus or full system. But you're looking at a few hundred bucks for that.
As far as sli games, no idea. I run a single 280x.
 
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Thank you again for your input. I have done a little more testing. Firstly, I suspect that much of the problem is that the hot air from the top card has nowhere to go because it is so close to the bottom card. To try to improve this, I removed the backplate from the bottom card, which increased the gap appreciably. Now, I can feel hot air coming out at a fairly even (and not inconsiderable) rate all the way along the gap between the two cards.

With the case open, running the The Division benchmark again (a total of 4 times), I find that the top card is not throttled to more than 1139.5mhz, albeit still reaching temperatures of circa 90C. Interestingly, it thermally throttles before turning the fans to maximum speed, although they get there eventually. I think that the cards came with software to adjust this behaviour (on CD-ROM - very 1990s), but I have not installed that yet. I probably should have a go.

I then, with the case side still off, added a spare 120mm fan resting next to the two cards, set to blow outwards from them, sucking the hot air from the gap between them out. The difference in doing this was less than I had expected (and less than the difference brought about by increasing the gap between the cards), although I did notice that it took longer to reach 1139.5Mhz, that the temperature did not exceed about 83C on the top card (the lower card being in the 60s), and that it would recover to a lower temperature and a higher clock speed more quickly. Given that 1139.5Mhz is still overclocked for this card, this is not too bad. However, the additional fan (this one is manually controlled, one of the removed case fans; I had it at the medium setting) does add considerable noise for a relatively small benefit. I have not yet tried again with the greater gap and the case side on. I further noticed that, with this extra fan, the fan on the top card never exceeded 90%.

I note also that, in The Division, the GPU loadings with SLI enabled are both quite low; although work is shared between the cards, neither card reaches 100%, the usual arrangement being 64% and 54% to the upper and lower cards respectively, although the upper card does spike into 71% frequently and up to 89% occasionally. I wonder whether, with a game that taxed both cards more thoroughly, the temperatures on the top card would be greater.

As to the water cooler, from what I understand, the EVGA water cooler is a hybrid design: in other words, it is intended for water cooling for the GPU itself, but air cooling for the memory, the power regulators, etc.. That air cooling relies on the reference cooler, as I understand it. My MSI card does not have a reference cooler, and the cooler that I do have would have to be removed, along with both of the fans, to fit the EVGA unit. How would I then cool the memory and voltage regulators if I were to fit the EVGA hybrid water cooler to this particular sort of card?
 

Napoleon

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The cards need cool air, perhaps you should try with the 120MM blowing onto the two fans so their own coolers have more fresh air. Have you thought about backing the clock speed back slightly?

You may want to look into corsair water cooling as they sell both the GPU cooler and also memory/power regulator adapters (note, for reference design). Regardles, buying an already assembled closed loop system is more simple than custom watercooling but you will not be able to thread the tubes through your case holes.
 
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Thank you for that. I did attempt puting a fan to blow onto the card (from the end rather than the side so that the air would not be blowing into where it needs to escape from), but this was not as good for temperatures/clock speeds as the fan sucking from the side. After playing The Division for a while, with the fan extracting, temperatures did reach circa 90C in the end, but with 1139.5Mhz. With the fan blowing rather than sucking, it dropped to circa 800Mhz on occasions, although did recover fairly quickly afterwards.

As to clocking back, surely that is what is happening automatically in any event when the thermal throttling is applied?

It seems as though the only remaining options are water cooling for the top card or cutting a hole in the case and adding an extractor fan. From what I have seen, that latter option delivers only fractionally better performance (in the games that I have tried so far, at least) than a single card solution, and hardly seems worth affecting the quietness of my computer for its much more common general use. Water cooling would be a happier result (a quieter computer, a cooler card that could therefore go faster), but I have no experience with water cooling. If I'd have known that this would have been a problem, I could have bought one hybrid card and one air cooled card, but I now have the two air cooled cards.

As to the Corsair cooler, do you happen to know the model name or at least what I should be looking for? I did search earlier, but it was a bit unclear.

Edit: Is this the one? I assume that I should need one of these to go with it? That Corsair bracket seems to have some very negative reviews, including "insane loud" and "bent my PCB".

Edit 2: That Corsair cooler will not work, as the PCB of my MSI 980Ti Gaming 6G is not a reference design: compare:

0d070fdd_front.jpeg


and

MSI-GTX-980TI-6GD5T-OC-GeForce-GTX-980-Ti-6GB-GDDR5_PCB.jpg


It seems as though only that special water block will fit.
 
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xmadror

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At first glance I'd say that your case looks to be optimized to be silent. Not a lot of intake/exhaust fan and the intake in the front are covered with a pretty restrictive panel.
It doesn't have a lot of room (easier to heat up) and the cable management could be better (disrupting the airflow somewhat).

I would seriously think about buying a new case that is more oriented for cooling performance along with a few fans, it might not be as silent but it doesn't need to be a noise maker either.
Something like a corsair air 540 or maybe even a 760t or 780t if your open to the idea of a full tower. (I like corsair's case, but there are many other good choice too)
It seems to me that those case could provide a lot more airflow even if the spacing of your card leaves to be desired and since the ambient temp inside the case would be lower your card would also run lower temp.
 
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Thank you for your suggestion. The trouble is that, most of the time, I do want to prioritise being silent over performance. It is only the occasions when I play games that the performance matters. When doing most things, a nice quiet case is just perfect. I had not anticipated when planning the upgrade that, without even seeking to over-clock the graphics cards, I should not be able to run them in SLI without considerably more cooling. (I know that the cards are factory overclocked, but they will scale back to below stock speeds with the case closed).

Changing the case would be fantastically disruptive, especially as it contains an Antec power supply that will only fit in Antec cases, and I do hate disruption. As far as I can see, there are three possible viable solutions:

(1) give up on SLI and sell the second card on eBay (or perhaps exchange it for one with a closed loop water cooler);
(2) cut a hole into the side of the case next to the cards and put a quiet 120mm fan with a high CFM rating into it (I have found that a low speed fan blowing air at the graphics cards works to maintain 1139.5Mhz with the case side open; I will have a go at modelling what it would be like with the case side closed but a hole cut in it using cardboard before actually cutting into my case); or
(3) use a water cooled solution with the EKB water block and a full loop (only the EKB water block is compatible with this card, and that would require a full conventional custom built water loop, rather than a simple closed loop system).

I am somewhat leaning towards option 2; it is likely to be vastly cheaper and easier than option 3, and option 1 would constitute giving up. I am also minded to connect the case side fan to the same fan header as the graphics card fan using a splitter cable so that the case side fan does not spin unless the graphics card fan spins, which should reduce idle noise. That, combined with the relatively closely spaced blades of a high-CFM fan should hopefully keep idle noise to acceptable levels.
 

kalston

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I would go with (1). 980 ti is a hot card, 2 of them is really lot of heat (for a not that impressive performance bump) - not that simple to keep things cool and quiet. I am also biased against SLI but hey, that's just my opinion here.
Also, I expect the new nvidia GPUs to be very attractive for people like us who value silence. Might be some actual news (non rumours) regarding those later on today.
 
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Apr 17, 2016
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34
Thank you for your input. I have been running some more tests.

Firstly, a thermal test: to see whether the temperatures would be maintained as well by cutting a hole in the side of the case and having a low noise fan blowing inwards onto the tops of the cards, but without actually damaging my case, I used two discarded cereal packets to form a testing case side and sellotaped them to the side of the case so that no significant amounts of air could escape. I had cut a hole in the side large enough to accommodate the 120mm fan just on top of the cards. The fan rested on a shelf inside the case, where it was blowing just at the cards. This proved to be a success, with thermal performance appearing to be slightly better than the fan pointing at the cards with the case open. The clock speed did not go below 1139.5Mhz when playing The Division for an extended period, and the temperature did not seem to exceed 84C (the card being rated up to 91C).

Secondly, in response to the latter post, I tried an SLI test. With SLI enabled, I was able to run NVidia's Apollo 11 demo at 4k in orbit mode at 35fps. With SLI disabled, this dropped to 21fps. Performance generally with SLI enabled was circa 30-40fps, and without SLI, 17-25fps. This demo (which can be downloaded for free on NVidia's website) is notoriously demanding as it involves real-time ray tracing. It was able to run it at 60fps in 1080p.

Finally, I ran an accoustic test. Using my mobile 'phone's built in microphone and a decibel meter app, I measured the ambient noise of the room at 28db, the sound noise of the computer on with the case side removed entirely but the computer not under load as 41db, the case side open with the fans manually set to run at the highest speed (apart from the fan blowing at the card, which is not an automatic fan, but has a three way switch, which remained at its lowest setting) as 48db, the same with the case closed as 46db and the case closed but the fans turned back to their default, low level, 41db again.

The conclusion of these three tests seems to me to indicate that the best way forward is option no. 2. I believe that the way to do this is to drill a circle of holes and cut from those. Can anyone recommend a good drill? I do not believe that I have such a tool.
 

pendragon1

Extremely [H]
Joined
Oct 7, 2000
Messages
41,172
you either need a regular coreded or cordless drill and jig saw with metal bits or purchase/rent/borrow a drill and 120mm metal hole saw. does not really matter what brand or quality, that is up to what you want to spend. just make sure the bits/saw are rated for metal.
 
Joined
Apr 17, 2016
Messages
34
After some research, I find that Antec's parts department sells the side cover with fan of the Antec P193 case:

1.jpg


I have e-mailed them to ask whether the side cover with the fan would fit my P183 case, and to order one if it does. This would be a much better solution than cutting a hole in my case if it could work.
 
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