martinm0 Posted June 19, 2015 Share Posted June 19, 2015 Hi all. I'm at a point where I'm ready to cut some holes in the Akitio outer case, but I'm having a hard time deciding on what I should do to maximize air flow (and not leaving the case structurally unsound). I love the clean cuts and look of bsohn's work: http://forum.techinferno.com/implementation-guides-apple/10099-2012-15-macbook-pro-gtx970%4010gbps-tb1-akitio-thunder2-win7-osx10-10-3-%5Bbsohn%5D.html, as well as the Dschijn's ingenuity using larger Noctua fans: http://forum.techinferno.com/implementation-guides-apple/9821-2014-15-mbp-iris-gtx970%4016gbps-tb2-akitio-thunder2-win8-1-osx10-10-%5Bdschijn-2%5D.html, and seefew's overall gusto in making it as mac looking as possible: http://forum.techinferno.com/implementation-guides-apple/10294-2011-11-mba-13-mbp-imac-gtx970%4010gbps-tb1-akitio-thunder2-osx10-10-%5Bseefew.htmlMy end goal is having a good looking, fully enclosed eGPU. My main concerns are ensuring enough airflow and cooling for my Zotac 970 and not bulking up the case (i.e., don't want any pieces to be attached on the outside like fan cages) if possible. I should have access to a CNC machine, so I believe I can do just about anything to the case, but this is where I start to waffle on what to do since any mods are permanent and I won't be able to go back.With that said, what thoughts or experiences do others have modding up their cases? For a build like seefew's does the cheese grater effect provide enough airflow? Does the video card need larger fans to properly cool it in an enclosed case, like in Dschijn's build? Are holes on the top of the case a must for passive cooling? I think I'd prefer to have some mesh or filter covering the holes, but also not sure there is enough room to make that happen. Has anyone tried to fit a slim 60mmx10mm fan between front fascia and the inner chassis (I had to remove the fan to fit the Zotac in, but think even a 10mm fan is too big to fit on the other side of chassis)?Looking forward to hearing what the community is envisioning! Quote Link to comment Share on other sites More sharing options...
Tech Inferno Fan Posted June 19, 2015 Share Posted June 19, 2015 @martinm0 , have you consider the best airflow is obtained without having the outer case on at all? You can always slide on the outer case to provide protectioning if transporting the eGPU enclosure from location to location. To have that a enclosure that can adapt to both situations, you would however need to choose low profile PCIe connectors, remove the sharp cut on the inner part of the AKiTiO chassis and use a card that fits, eg: Galax/KFA2 GTX970. 1 Quote Link to comment Share on other sites More sharing options...
martinm0 Posted June 19, 2015 Author Share Posted June 19, 2015 I do currently run it unsheathed, but I really would like it to look more prim and proper with the outer case on it. I also grabbed one of the super low profile Aktito eGPU cables from eBay, so closing it up is not a problem at this point (though setting up some internal wiring with the Dell DA-2 is still on the list). I did run the unit fully closed with the front fan removed and it was nice not seeing all the wires and such, but obviously heat became an issue as soon as I stressed the GPU.Do you believe that cutting holes will add sufficient air flow for a 970 GPU? Sure, if I hack 90% off, but would an oval hole on the side of the case near the GPU fans, holes in the top of the case and an exhaust fan in the front offer enough cooling? I don't want just adequate cooling if I'm going to butcher the case...lol. Quote Link to comment Share on other sites More sharing options...
Dschijn Posted June 19, 2015 Share Posted June 19, 2015 I think you need to make sure that fresh air can come in and warm/hot air gets out. I am using the 2x92mm fans so close to the outer case, that there is no way that my fans can suck in air from inside the case. By that they also get 100% fresh air and create a positiv air pressure inside the case. That positiv pressure is forcing the air from inside the case to exit at any possible way. For that I made 3x60mm cuts in the top, which is way too much My aim was to make the setup run very quiet and cool at the same time. When doing it the way seefew or bsohn are doing it, I see the risk of the fans "re-using" air from inside the case. Best way to avoid that would be to build a air tunnel from the fans to the case. By that you could make sure that the fans only "suck in" fresh air. The way the intake is opened or covered is up to you, but the more the air has to be forced through small holes, the louder it gets because the fans need to work harder to get the amount of air. The exhaust can be done by some holes or slots that just provide an exit for the hot air. 1 Quote Link to comment Share on other sites More sharing options...
martinm0 Posted June 19, 2015 Author Share Posted June 19, 2015 My aim was to make the setup run very quiet and cool at the same time.The exhaust can be done by some holes or slots that just provide an exit for the hot air. Did you find your enclosed case to run at temps similar to an open case? I know you posted temps, but I don't recall seeing you specifically state open vs enclosed. And I've been meaning to ask you to post a video of the eGPU's noise levels (I know that's hard to do without proper tools and space). I'm starting to lean towards the cheese grater effect to allow ventilation in as well as keep structural integrity in place and hopefully limit dust and dirt from being pulled in. I'm just not sure if that will allow enough air flow to properly cool. Quote Link to comment Share on other sites More sharing options...
Dschijn Posted June 19, 2015 Share Posted June 19, 2015 you mean open vs. closed like before vs. after my mod? Because open or closed after my mod doesn't make a difference. I even think that my closed case will give me better temps This is the fan I am using now, should be sth like 9-10v most of the time I am playing games. Hard to tell the voltage to compare it to, since I regulate them by PWM: Quote Link to comment Share on other sites More sharing options...
martinm0 Posted June 19, 2015 Author Share Posted June 19, 2015 I even think that my closed case will give me better temps Get testing and prove it!! If you get better temps in a closed case, I'm going to butcher mine and make it so! But damn, I wish Noctua made those fans in the gray color they use in the redux models. Regarding adding the Noctua fans, did they fit between the bracket on the GPU and the case with out modification? The Zotac has 4 posts that the fan shroud connected to (vs your full bar). I'm wondering if I'd have enough space or if these would have to be bent back. Also, can you link the PWM splitter you are using? Thanks!! Quote Link to comment Share on other sites More sharing options...
Dschijn Posted June 19, 2015 Share Posted June 19, 2015 The Galax GTX970 has some bumpers on the side of the cooler to attach the stock fan+shroud. Because of that, the Noctua I use are not directly on the cooler itself, but more hovering 5mm above that. With the fans (14mm thick, not the 25mm ones) the case closes perfetly, there is just a 1mm gap to the outer case. Problem was that the screws holding the fan grills need to be countersunks to not collide with the fans when opening/closing the case.Using this PWM splitter: Mini 4-Pin GPU to 2 x 4-Pin FWM Fan Adapter - modDIY.comJust be aware! PC fan PWM and PWM from the GPU are not really the same, but I can't understand why…With the stock fan profile of the card, it's making the Noctuas to run at full speed with sth like 40% fan speed signal from the GPU. That means that in OSX the fans will always run at full speed when the card is under load. In Windows I made a custom fan profile that lets the card run smooth and quietup to 70°C. Above 70°C the fans get audible.I don't really see the point to prove that the GPU is getting same results with or without the case. I cut it open so much, that the fans have no restrictions to pull in air and hot air can easily exhaust through the top.Without the case I could imagine that the fans might reuse warm air more often, since the warm air is exhausting into every direction, while my case is forcing the air into a direction. Quote Link to comment Share on other sites More sharing options...
Dschijn Posted June 20, 2015 Share Posted June 20, 2015 @martinm0: So here is my test: Here are some pictures that show how I attached the fans and how much space is between the fans <-> heatsink and fans <-> case: I tested with and without the outer case. The card was always sitting inside the inner cage. To be able to compare the tests I set the Noctua fans to 100% fan speed (60% PWM signal from the GPU) which is a bit more than 2100rpm. Furmark 1600 resolution and 4x AA: with case: Hitting 79-80°C temperature target -> throttling clock speed to sth aroung 1400MHz without case: Hitting 79-80°C temperature target -> throttling clock speed to sth aroung 1400MHz The Witcher 3 (settings from my gameplay video): with case: temperatures between 72-73°C had one spike of 74°C after moving camera without case: temperatures between 70-71°C with case withour case With my owm fan profile I never get higher than 76°C (with case) and the fans stay below 2000rpm. 1 Quote Link to comment Share on other sites More sharing options...
martinm0 Posted June 22, 2015 Author Share Posted June 22, 2015 @Dschijn - Thanks again for all the testing and info above! I've been caught up in work and other life issues so haven't had a chance to respond. I did end up picking up a pair of the Noctua fans thinking that extra cooling is never going to be a bad thing. Unlike your setup on the Galax 970, the Zotac has 4 posts that the shroud connects too. The fans almost fit between these brackets, but not quite, so I've bent them out about 50 degrees and now the fans can be wedged in between the posts, which leaves me several millimeters of space between the fans and the outer case (not sure if that's going to be good or bad yet with drawing fresh air into the case). I have to wait probably until the end of the week until the PWM splitter comes in from Hong Kong before I can do any testing, but just wanted to say thanks for all the info and sorry for stealing your ideas! (PS - I'll get my build added soon so the community can see my work.) Quote Link to comment Share on other sites More sharing options...
Dschijn Posted June 22, 2015 Share Posted June 22, 2015 @martinm0: Sure thing! Just be aware that in OSX the Noctua fans will spin up pretty fast, since you can't change the fan curve. In Windows that is quite easy with MSI Afterburner or sth similar. For me 60% PWM signal results in 100% fan speed. Quote Link to comment Share on other sites More sharing options...
martinm0 Posted June 22, 2015 Author Share Posted June 22, 2015 @martinm0: Sure thing! Just be aware that in OSX the Noctua fans will spin up pretty fast, since you can't change the fan curve. In Windows that is quite easy with MSI Afterburner or sth similar. For me 60% PWM signal results in 100% fan speed. Are you saying that the Noctua fans behave differently in OS X over the stock GPU fans, or just that OS X lacks the options of customizing the fan profile? I feel like my stock fans are still dynamic in OS X and Windows (haven't set a profile for them yet in MSI Afterburner). Also, what are your profile settings in MSI? I tried setting some profiles and found the fan went to full speed (is this the 60%=100% fan speed you mentioned above)? I care a little about fan noise, but more just want to eh GPU to stay under 80 C. Quote Link to comment Share on other sites More sharing options...
Dschijn Posted June 22, 2015 Share Posted June 22, 2015 That is sth that doesn't really makes sense to me, but I was able to have that exact same problems on different GTX970s and different fans. The GPU can control it's stock fans between 0 - 100% (some can't go lower than 20-30%). Within that range the fans will change its fan speed. By the wires of the fan plug it is obvious that the fans are PWM controlled. If I connect a desktop PC fan the following happens: 0% - fan turns of (Noctua fans can do that with a 0% PWM signal), happend on my old EVGA GTX 970 30% - that is the minimum of my Galaxy card (in MSI Afterburner) - the NOCTUA NF-A9x14 fans are at 1000rpm 60% - desktop PC fans are working at full rpm, with the NOCTUA NF-A9x14 that is 2200rpm So I created a fan profile for my Galaxy card to control the fans between 30-60%. That fan profile is software controlled in Windows with MSI Afterburner. If I boot into OSX the card is running on it's stock fan profile in the GPUs BIOS. What happens is that the stock fan profile is getting much faster to 60% fan speed signal (maybe at 60-65°C) and from that moment on the NOCTUA NF-A9x14 fans are at full speed. The strange thing is... 60% fan speed signal should be 60% PWM signal, but the Noctua fans seem to get a 100% signal. What are the fans getting with a fan speed signal higher than 60%? How are stock fans controlled to work beyond 100% PWM? I don't know... To get a custom fan profile in OSX, we would have to edit and reflash the GPUs BIOS, but that doesn't seem to work over TB. This are my MSI Afterburner settings WITH the Noctua fans: 1 Quote Link to comment Share on other sites More sharing options...
martinm0 Posted June 22, 2015 Author Share Posted June 22, 2015 That's all really good info, thanks! Is it possible the PWM splitter is causing issues? I'll do more testing once I have my splitter in and see if I have the same issues. Quote Link to comment Share on other sites More sharing options...
Dschijn Posted June 22, 2015 Share Posted June 22, 2015 No PWM splitter is fine. Seems to be the PWM signal itself.On my old EVGA I used another PWM Splitter that is just receiving the PWM on one wire and sending back on another wire the RPM signal. 12V and ground I got directly from the PSU by a Molex plug.With the GALAXY card I get all 4 from the PWM splitter and have the same behavior. Quote Link to comment Share on other sites More sharing options...
ljwebb236 Posted August 20, 2015 Share Posted August 20, 2015 @Dschijn, would it be possible to use the fan power connectors already present on the zotac 970 to power larger fans closer to the outer case wall? This way, the GPU itself would be able to control the fan speed. Quote Link to comment Share on other sites More sharing options...
Dschijn Posted August 20, 2015 Share Posted August 20, 2015 Yes, but most connectores are limited in the max power they can deliver. So two fans might work as well.But you should be aware of two things:- the fan connector on the GPU is smaller than the one of bigger fans- you can always use a PWM splitter with an additional power source (that is what I am doing)I connected two adapters to the GPU. 1. to get the mini 4-pin to bigger 4-pin and 2. a splitter that is just using the PWM and tacho connections to the GPU and that provides 12V and ground directly from the PSU. Quote Link to comment Share on other sites More sharing options...
ljwebb236 Posted August 20, 2015 Share Posted August 20, 2015 You mean something like this, and then a Y cable for 2 PWM connectors for full sized fans correct? Also is there a specific reason you chose to go with the Noctua brand? Quote Link to comment Share on other sites More sharing options...
Dschijn Posted August 20, 2015 Share Posted August 20, 2015 For a start this cable is good (had one of those): Mini 4-Pin GPU to 2 x 4-Pin FWM Fan Adapter - modDIY.com I just remembered that I am actually using THAT cable without additional power running the two fans I took Noctua because I am totally into their fans and they are the ONLY fans with: - 92x92x14mm - PWM I had to go with 14-15mm thick fans since the space I have inside the AKiTiO is very limited and 25mm thick fans will NOT fit. PWM because I want to controll the fans speed Quote Link to comment Share on other sites More sharing options...
ljwebb236 Posted August 24, 2015 Share Posted August 24, 2015 The cable described in the link is no longer there , but I see. Ok cool I see see what you're saying about the fans. I think I will try the splitter method as soon as I am able to cut an openning in the case. Quote Link to comment Share on other sites More sharing options...
Dschijn Posted August 24, 2015 Share Posted August 24, 2015 The cable described in the link is no longer there , but I see. Ok cool I see see what you're saying about the fans. I think I will try the splitter method as soon as I am able to cut an openning in the case. There you go: Mini 4-Pin GPU to 2 x 4-Pin PWM Fan Adapter - modDIY.com Quote Link to comment Share on other sites More sharing options...
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