SFF airflow question

[sliv]

There's two ways air can enter, the top or the front (120mm intake fan at the top, cpu heatsink intak in the front), and one way to exit (80mm psu exhaust). What has me worried is that little fan trying to pull air out of the case.
I know how these sff systems like to get hot, so everything will be at stock speeds... unless the temps allow for overclocking, then I will maximum power this little monster

Keep in mind that while the GPU and CPU Heatsink are to scale, the rest may be off by ~.5". Also, the "separator" is actually part of the case, I just had to lower the opacity of the outer chassis to make things visible. The gpu connects to pcie x16 slot via riser, oh, and keep the laughter to a minimum please, this is my first time using sketchup

Zotac GTX 660 Ti "short" (green)
Kozuti Scythe (blue)
Silverstone 450W SFX Bronze
2x4gb 1600 ram
Mini-ITX motherboard
64GB SSD
1TB Internal

 

[SithSolo1]

I'd be worried about all heat in the case is being forced into the psu. Also with the psu oriented like that you have little room for the cables as they may be hitting the fan side of the case when exiting the psu.

 

[sliv]

The psu will likely be modded to move the cables from the wall to the inside. Or I may just remove the cover and relocate them, we'll see. In this update I tried to resolve the psu airflow issue. I removed the top 120mm and replaced it with two 80mm Noctua fans on the sides. With some strategically placed air vents could layout this work?

The idea is the front 80mm intake will provide air for both the video card and cpu, and the heat from those will be split between the 80mm exhaust and the psu. If this works, do you guys think I'll still need the divider, or will the airflow be better without it?

This is to give an idea of the size I'm going for

 

[illli]

picture 3 is something close to an idea i have been mulling for quite some time. not sure if you considered using a ribbon cable instead of a riser card, but ribbon cables wont work very well. i researched ribbon cables, and even the 'shielded' ones are not very reliable.

 

[fixitman]

picture 3 is something close to an idea i have been mulling for quite some time. not sure if you considered using a ribbon cable instead of a riser card, but ribbon cables wont work very well. i researched ribbon cables, and even the 'shielded' ones are not very reliable.

+1, from what I have seen, ribbon cables do not work well with good video cards.

 

[fixitman]

Also, your layout for the hard drives probably wont work, need room for the cables. Looks like right angle cables will add about 1/2" or so.

on the first drawing, if you put the power supply on the other end, positioned so that it pulls air from outside, and exhausts out the back, you wind up with the same size case, and the power supply does not add to the heatload of the case. Then you can put a couple of 60 or 70 mm case fans to pull air out of the case at the end opposite of the new power supply position. There should be enough room over the sata connectors. Just an idea anyway.

 

[sliv]

picture 3 is something close to an idea i have been mulling for quite some time. not sure if you considered using a ribbon cable instead of a riser card, but ribbon cables wont work very well. i researched ribbon cables, and even the 'shielded' ones are not very reliable.

I've read that both risers and ribbon cables work fairly well actually, even seen two of them connected to each other supporting a high end video card with no issues. I think as long as it's high quality it should be alright. Could you please show the source where they show the shielded ones are unreliable?

+1, from what I have seen, ribbon cables do not work well with good video cards.

Where have you seen this? It may be that I'm getting biased google search results, but I've only seen positive things so far..

Also, your layout for the hard drives probably wont work, need room for the cables. Looks like right angle cables will add about 1/2" or so.

on the first drawing, if you put the power supply on the other end, positioned so that it pulls air from outside, and exhausts out the back, you wind up with the same size case, and the power supply does not add to the heatload of the case. Then you can put a couple of 60 or 70 mm case fans to pull air out of the case at the end opposite of the new power supply position. There should be enough room over the sata connectors. Just an idea anyway.

Thanks for the excellent idea, can't believe I overlooked it! I'll sketch it up in a bit and see how it turns out.

 

[illli]

About the ribbon cable. Several months ago I tried to find one that could handle a modern-day high end video card. At the time i was looking for something to 100% reliably run a gtx690, so this might not apply to you. Anyway, I contacted a company that makes them and spoke with one of their engineers. From what i was told there is something called impedance which i dont really understand but basically proper shielding of the ribbon cable is essential. And this is what separates the cheap ones you see just about everywhere.

best one i found was the PE-FLEX16KR-3 ...however, it is supposedly so good that they only sell them to companies. At the time, they told me they won't sell them to general public, but it probably would be too costly if they did. Their older model still goes for $50+. So while i've found that at least one quality ribbon cable that ~should~ in theory work for high end video cards, it is much less of a hassle to just use a riser card.
They are cheaper to find and dont have to worry much about this impedance thing when using a ribbon cable.

 

[sliv]

About the ribbon cable. Several months ago I tried to find one that could handle a modern-day high end video card. At the time i was looking for something to 100% reliably run a gtx690, so this might not apply to you. Anyway, I contacted a company that makes them and spoke with one of their engineers. From what i was told there is something called impedance which i dont really understand but basically proper shielding of the ribbon cable is essential. And this is what separates the cheap ones you see just about everywhere.

best one i found was the PE-FLEX16KR-3 ...however, it is supposedly so good that they only sell them to companies. At the time, they told me they won't sell them to general public, but it probably would be too costly if they did. Their older model still goes for $50+. So while i've found that at least one quality ribbon cable that ~should~ in theory work for high end video cards, it is much less of a hassle to just use a riser card.
They are cheaper to find and dont have to worry much about this impedance thing when using a ribbon cable.

I guess I should have mentioned that I don't mind losing a few % of performance in exchange for case form factor, if anything I'd just overclock a bit? However it good to know that quality pci-e riser/ribbons do exist, and since this build is something I plan on keeping for a while, I don't mind spending a little extra on the parts, thanks for the link, I'll keep it around just in case .

A friends of mine talked me into seeing how much space can be squeezed out of the "case" if there was no riser card.... turns out is almost exactly the same hahahaha. So all this hassle for nothing really, looks like I can just plop the video card in the pci-e slot, and not only do I avoid the risky riser altogether, this setup is loaded with benefits!

-can fit 3x 2.5" HD.
-better airflow.
-easy access.
-easy setup.
-calls me handsome.

Current parts list:
Zotac GTX 660 Ti "short"
Xigmatek Nepartak
Silverstone 450W SFX Bronze (or possibly gold)
2x4gb 1600 ram
Mini-ITX motherboard
64GB SSD
1TB Internal
2x Noctua 60mm fan (exhaust)
1x 90mm fan (intake)

-The intake fan on the psu would face away from the board and therefor remove any heat added to the case/not interfere with airflow (possibly separated by a sheet of aluminum).
-The heat from the gpu board would channel into the exhaust on the back, while it's heatsink would be independently cooled by the stock fans.
-The heat from ran and hd's would funnel into the exhaust fans as well.

My question is about the airflow, and whether it will be enough to keep things cool (for possible overclocking, but if not that's alright). Would I have to attach the 92mm fan that came with the cpu heatsink, or can I keep it passive using the case fans? Also, would you suggest switching out the single 92mm intake fan to 2x 60mm like in the exhaust?

 

[fixitman]

Actually, if you rotate the power supply 90 degrees, so that it exhausts out the back of the case, you will wind up with more room inside the case.
I say this because the video card plus motherboard, plus video card power connectors works out to about 5 1/2 inches tall, and the power supply is 5 inches wide. This way your power cable goes in from the back, instead of some weird wiring.
Your current set up is very similar to a project I was working on, so I have all the parts sitting next to me right now
I opted for a slightly smaller set up, with the power supply over the motherboard. Total size should wind up 6 inches wide, 7 1/2 inches deep, and 8 inches tall (possibly 9 inches, depending on if I decide on some bigger exhaust fans). Mine will be oriented so that the video card is on the bottom of the case, sucking fresh air from under the case, with exhaust fans at the top to pull air through the case.

edit: I opted for 6 inches wide, when I could go as small as 5 1/2 inches, because the aluminum sheets I got from Home Depot are 6 inches wide.... so convenience wins

 

[sliv]

Actually, if you rotate the power supply 90 degrees, so that it exhausts out the back of the case, you will wind up with more room inside the case.
I say this because the video card plus motherboard, plus video card power connectors works out to about 5 1/2 inches tall, and the power supply is 5 inches wide. This way your power cable goes in from the back, instead of some weird wiring.
Your current set up is very similar to a project I was working on, so I have all the parts sitting next to me right now
I opted for a slightly smaller set up, with the power supply over the motherboard. Total size should wind up 6 inches wide, 7 1/2 inches deep, and 8 inches tall (possibly 9 inches, depending on if I decide on some bigger exhaust fans). Mine will be oriented so that the video card is on the bottom of the case, sucking fresh air from under the case, with exhaust fans at the top to pull air through the case.

edit: I opted for 6 inches wide, when I could go as small as 5 1/2 inches, because the aluminum sheets I got from Home Depot are 6 inches wide.... so convenience wins

I'd love to see pictures if you have any. Are you channeling the air inside the case around the psu, or did you end up modding it to allow for air to pass through it?

I took your advice and mocked it up in sketchup... you're absolutely right. I overlooked the gpu connector, once you factor that in the vertical psu makes much more sense. It also solves the issue of not having the psu power connector on the side as the others, thanks!

You know how they say with great power comes great responsibility, well now I have all this space and I must utilize it!... just don't know how yet. Maybe another fan? Or better yet a fan controller. Any ideas?
Here's the (rough) newly available space thanks to fixitman. Keep in mind the ram sticks out a little through the highlighted area, so it has to work with the space.

 

[SithSolo1]

move the hdds into the empty space and you will actually have room for the psu cables without modifying the psu.


Edit: Rotate the HDDs 90 degrees, put them up against the short wall of the case, and slide them all the way to the front wall. You may have room for them, the psu cables, and a small fan controller then.

 

[fixitman]

Well, the project is currently on hold, and I don't have any pictures yet.
My current plan is to have the air flow go around the power supply, coming in from the bottom (video card end), and exit the top. I will probably have some duct work for the cpu cooler so that it sucks air from outside the case. Basically, the plan is to have all the coolers and heat sources draw air directly from outside the case, and then exhaust the hot air out the top. I don't know if it will work, but if it doesnt, the case will be easy to modify.

 

[She loved E]

Good setup. I agree with SithSolo that you can move the HDDs into the open space and you'll have room for cables.

A duct on the CPU cooler is a great idea. You might even be able to fit two 92mm fans for a bit more flow than the single 120 you have now... if you have enough width to do it.

Edit: just realized you're already using a 90mm on the front. Why so small? Isn't the height of the case dictated by the taller CPU cooler anyway?

 

[fixitman]

Hmm, it does look like the current cpu cooler choice might be a bit tall. That cooler is 134mm tall. Current drawing shows the interior of the case at 119.6mm.

EDIT: I just measured a motherboard with that zotac video card installed, with power connector. it is about 134mm from the top of the power connector wires to the top surface of the mother board. So if the case is made just a little bigger, the current cooler choice could be made to fit.

EDIT AGAIN: just a FYI, once you figure in power connectors for the video card, and stand offs for the motherboard, you are looking at around 145 mm overall interior height. Might be able to shave a little off, by modifying the power connector and going for as short of stand offs as possible. you could conceivably get it down to 130 mm, but the shorter you go, the more you add extra work and complexity, and limit your options.

 

[sliv]

move the hdds into the empty space and you will actually have room for the psu cables without modifying the psu.


Edit: Rotate the HDDs 90 degrees, put them up against the short wall of the case, and slide them all the way to the front wall. You may have room for them, the psu cables, and a small fan controller then.

Thanks man, a 3.5" fan controller fits in there perfectly (5.25" is too big).
I'm still debating whether it will actually take away from aesthetics or not, but I'll keep looking for one I like. I'll keep the orientation of the HD's like you suggested, seems to work out great

Well, the project is currently on hold, and I don't have any pictures yet.
My current plan is to have the air flow go around the power supply, coming in from the bottom (video card end), and exit the top. I will probably have some duct work for the cpu cooler so that it sucks air from outside the case. Basically, the plan is to have all the coolers and heat sources draw air directly from outside the case, and then exhaust the hot air out the top. I don't know if it will work, but if it doesnt, the case will be easy to modify.

Don't know why, but it reminds me of this
I'm assuming you're going to have some kind of feet to raise the case off the ground to suck air from the bottom, but do you think there will be enough room between the floor and the case to provide sufficient airflow? I may have to do the same so I'm wondering if an inch of space is enough.

Good setup. I agree with SithSolo that you can move the HDDs into the open space and you'll have room for cables.

A duct on the CPU cooler is a great idea. You might even be able to fit two 92mm fans for a bit more flow than the single 120 you have now... if you have enough width to do it.

Edit: just realized you're already using a 90mm on the front. Why so small? Isn't the height of the case dictated by the taller CPU cooler anyway?

The cpu heatsink isn't the standard 120mm, but a 92mm Xigmatek Nepartak , therefor not necessarily dictating the size of the case.
I can replace the front 92mm intake with a 120mm but it would be at the cost of bigger case. If the current configuration can provide adequate cooling I'd prefer to keep it as is.

While 2x 92mm fans won't fit, 2x 60mm on each side will, and in return a single 92mm on each side will work as well. Do you think one of these will have better airflow than the one previously posted?

Hmm, it does look like the current cpu cooler choice might be a bit tall. That cooler is 134mm tall. Current drawing shows the interior of the case at 119.6mm.

EDIT: I just measured a motherboard with that zotac video card installed, with power connector. it is about 134mm from the top of the power connector wires to the top surface of the mother board. So if the case is made just a little bigger, the current cooler choice could be made to fit.

EDIT AGAIN: just a FYI, once you figure in power connectors for the video card, and stand offs for the motherboard, you are looking at around 145 mm overall interior height. Might be able to shave a little off, by modifying the power connector and going for as short of stand offs as possible. you could conceivably get it down to 130 mm, but the shorter you go, the more you add extra work and complexity, and limit your options.

Initially I thought the cooler was 92mm tall so this kind of changes things. By kind of I mean with the measurements of the mobo and gpu that you mentioned, even the current sized cpu heatink should fit, but if not I'll have to go shopping for a different 92mm cooler.
Also, is your Zotac the 660ti? I'm curious whether it is the same height as the one I'm working with (btw this card isn't the final choice, just the current). Either way the measurements are very useful information, thanks.

I'm trying to keep as many warranties in tact as possible, the gpu and psu ideally fitting in the setup as is. With that said, I doubt I'll be modifying the the gpu connector, but I am leaning toward removing the fan shroud to reduce the width of the case by a possible ~10mm (again, depending on warranty voidance). I honestly didn't even factor in stand offs before, but now that you mentioned it I'll go for the smallest ones I can find.

 

[fixitman]

I think the 92mm case fans will probably give the best airflow, and be the quietest. It is also easier to get good quality 92mm fans than 60mm ones.

At a cost of about 5mm case length, you can fit 2 80mm fans where the 60s are. I dont know if it is better than a single 92, but it might be.

And damn Zotac, why the heck did they place the power connector on the top of the card, instead of on the end. The damn fan shroud extends past the end of the card anyway, why not point the power connector that way instead

 

[sliv]

I think the 92mm case fans will probably give the best airflow, and be the quietest. It is also easier to get good quality 92mm fans than 60mm ones.

I agree that the 92mm would provide the best airflow, and since I want to have as little noise as possible it is the ideal setup. Especially since the new cpu cooler I'm looking at already comes with two, and this little guy is not only smaller in height (125mm), but uses ultra quite Noctua fans as well.
However, I'm afraid that by focusing air on the cpu heatsink with single 92mm intake/exhaust, things like ram, north/south bridge and hdd's won't have air passing over them due to the "funnel", and cause a heating issue. Am I just being paranoid or can this actually happen?

The heatsink is the Noctua NH-U9B SE2 92mm I mentioned earlier. Unfortunately my sketchup skills don't allow me to create my own models, only modify existing ones, so you're seeing a stretched Xigmatek Nepartak in Noctua's place. The dimensions are more or less to scale so it'll work for the demonstration .
Which one would work better?
(left 80mm, right 92mm)

At a cost of about 5mm case length, you can fit 2 80mm fans where the 60s are. I dont know if it is better than a single 92, but it might be.

Well, looks like the 2x60mm idea is out the window (see above ), it didn't work before because of the incorrect heatsink height measurements restricting fan size, but now it fits with room to spare.
I tossed in the 2x 80mm fans but I think your measurements are off.
2x 80mm = 160mm, mini itx mobos are 6.7", or 170mm. 170-160=10mm.
If anything the overall size should be smaller, no?




I also noticed that I can now fit 2x intake 92mm fans side by side to possibly increase airflow and lower noise but there's a problem. By not having enough room in the back of the case for the same 2x fan setup, I'm forced to turn the psu back around and exhaust through it. The hot air passing through the psu will force the fan to kick up and the noise level to raise with it. The only way this would work is if the components stayed cool enough to not demand more airflow. Will temps allow for this setup to stay quite (with a possible overclock)?

And damn Zotac, why the heck did they place the power connector on the top of the card, instead of on the end. The damn fan shroud extends past the end of the card anyway, why not point the power connector that way instead

Seriously... Zotac is retarded for placing the connector at the top. When making a "short" card one has to be under the assumption that there is limited space available, and taking up ~1" of space for the connector seems illogical, especially when the fan shroud protrudes in the perpendicular direction. PNY got it right (360 view), why couldn't Zotac
edit*
Zotac gets it wrong with the 650ti also

 

[fixitman]

By the way, you are showing the video card exhausting air, but it goes the other way

Looking good though!

 

[sliv]

By the way, you are showing the video card exhausting air, but it goes the other way

Looking good though!

fixed

 

[Computer Ed]

The dual front with the single rear can work without turning around the PSU. Put a few vent holes at the top rear of the case and the positive pressure will force air through the top and use the natural rise of the heat to help expel the warm air.

 

[sliv]

The dual front with the single rear can work without turning around the PSU. Put a few vent holes at the top rear of the case and the positive pressure will force air through the top and use the natural rise of the heat to help expel the warm air.

Since the Noctua heatsink already comes with 2 fans, the arrangement you mentioned will be one of the first to be tested .
And if you're wondering, the actual case design is lookin good too, I'l update the thread once the build starts