top-down blowing design?
Printed From: ASRock.com
Category: Technical Support
Forum Name: AMD Motherboards
Forum Description: Question about ASRock AMD motherboards
URL: https://forum.asrock.com/forum_posts.asp?TID=1636
Printed Date: 15 May 2024 at 5:15am
Software Version: Web Wiz Forums 12.04 - http://www.webwizforums.com
Topic: top-down blowing design?
Posted By: bjlockie
Subject: top-down blowing design?
Date Posted: 31 Dec 2015 at 11:46pm
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I have this motherboard with FD8370FRW8KHK http://asrock.com/mb/AMD/Fatal1ty%20970%20Performance/index.us.asp?cat=CPU The FAQ says: >For cooling the CPU and its surrounding components, please install a CPU cooler with a top-down blowing design. I have this cooler: http://www.deepcool.com/product/cpucooler/2013-12/7_481.shtml What is a top-down blowing design? |
Replies:
Posted By: Xaltar
Date Posted: 01 Jan 2016 at 12:15am
| The Gammaxx 300 is not a top down cooler it is what is known as a tower cooler. A top down cooler has the fan oriented parallel to the motherboard. Google search "Top down cooler" and you will be greeted with a broad array of coolers. The best ones for the purpose you need are the type that look like a tower cooler that has been bent 90 degrees and now blows directly onto the motherboard and CPU. |
Posted By: PetrolHead
Date Posted: 01 Jan 2016 at 12:40am
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The best I've come across is the Noctua NH-C14S. However, it's not very good if you plan to heavily overclock your CPU, since it's only recommended for max 140W TDP. I think this might be a common problem with these type of coolers. ------------- Ryzen 5 1500X, ASRock AB350M Pro4, 2x8 GB G.Skill Trident Z 3466CL16, Sapphire Pulse RX Vega56 8G HBM2, Corsair RM550x, Samsung 960 EVO SSD (NVMe) 250GB, Samsung 850 EVO SSD 500 GB, Windows 10 64-bit |
Posted By: parsec
Date Posted: 01 Jan 2016 at 1:30am
WOW, someone actually read the fine print in the CPU Support list!!  bjlockie, good for you, most people don't even notice that. It is important when using an FX-8000 or FX-9000 series CPU. The reason for that is the CPU VRM heatsink needs air flow over it to keep it cool with the high power usage FX-8000 or FX-9000 series processors. Here's an example of how this works:  But don't think you must use a top down blowing design CPU cooler. It is possible to have enough air flow over the VRM heatsink with the fans in your PC case. Fans mounted in the top and/or the top rear location of your case will provide some air flow over that heatsink. It may be also possible to mount a small (80mm) fan that pushes air across that heatsink. ------------- http://valid.x86.fr/48rujh" rel="nofollow"> 
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bjlockie wrote:Posted By: bjlockie
Date Posted: 01 Jan 2016 at 3:03am
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I read the FAQ after I bought it. :-( The box should have said it has a limitation. I think I am ok because I have an Antec One case which has a top case fan and my motherboard temps from th4e BIOS seem ok. I'm trying to set up Linux to read the temperatures but I'm having problems. |
Posted By: wardog
Date Posted: 01 Jan 2016 at 3:37am
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http://www.deepcool.com/product/cpucooler/2013-12/7_481.shtml I'd like to think you'd be ok using this. It's rated for the FX 8-cores and that overhanging fan on the bottom should blow some in the direction of the VRM section anyway.
Indeed. |
Posted By: PetrolHead
Date Posted: 02 Jan 2016 at 5:54am
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I agree with wardog, the VRM temp should be fine with that. My VRM temp (or the temp I'm assuming is the VRM temp) actually went up after installing a top-down blowing CPU cooler. This is because both the CPU and the socket are now cooled more efficiently, meaning that the air that blows over the VRM section is warmer than before, and thus less efficient at keeping it cool. It's the socket temperature I'd worry about most in your case, bjlockie. That's what nearly caused me trouble with a tower cooler. You don't necessarily need to get a new CPU cooler, if you can use a spot fan to blow air on the socket. OT: "It is important when using an FX-8000 or FX-9000 series CPU." Not really true for the latter. There's a reason AMD provides a stock liquid cooler with those CPUs; air cooling is just not enough for that CPU (at least not with something that fits in a normal case). The motherboard needs to be cooled using something else than a top-down blowing CPU cooler. ------------- Ryzen 5 1500X, ASRock AB350M Pro4, 2x8 GB G.Skill Trident Z 3466CL16, Sapphire Pulse RX Vega56 8G HBM2, Corsair RM550x, Samsung 960 EVO SSD (NVMe) 250GB, Samsung 850 EVO SSD 500 GB, Windows 10 64-bit |
Posted By: wardog
Date Posted: 02 Jan 2016 at 12:28pm
Yea. It doesn't look bad. But OP, keep a close watch at how hot the VRM sinks are.
I think more to parsecs point is that an extra fan (jury)rigged to blow over the VRM section is practically a must. More so with boards that are 4+1 and even some cheaper 8+2 boards with no or even skimpy sinks covering them. Has anyone here ever read what the instruction that come with the included water coolers that come on the high end FX silicon? It'd be really interesting to see whether AMD themselves, like practically everyone else does, not mention additional or supplemental VRM cooling. |
Posted By: parsec
Date Posted: 03 Jan 2016 at 1:59am
This, This, This!! That is a huge contradiction! An AIO water cooler is needed (minimally) for these processors, which by the nature of their design is as far from a top-down blowing cooler as we can get. So using an AIO cooler provides zero cooling for the VRM heatsink. Yet the warning note about using a top-down blowing CPU cooler suddenly becomes unnecessary with an AIO cooler? Of course not! The illogical nature of this is obvious. Two issues exist, cooling the CPU and VRMs when using FX-8000 and FX-9000 series processors, but the AIO CPU cooler only addresses one of those issues. Are the 990FX board's VRMs exempt from needing extra cooling? The top-down blowing cooler warning is not mentioned in the 990FX Extreme9 CPU support list, but is included in the 990FX Extreme6 CPU support list, along with the AIO cooler warning. The 990FX Extreme9 has a more robust VRM heatsink, but lesser boards don't. So your point wardog is extremely important IMO. The 990FX Extreme9 cannot be the example for CPU and VRM cooling for other AMD boards when using the FX-8000 and FX-9000 series processors. ------------- http://valid.x86.fr/48rujh" rel="nofollow">
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Posted By: PetrolHead
Date Posted: 03 Jan 2016 at 6:23am
Apologies, I read parsec's post all wrong. I thought he was referring to the use of top-down blowing desing, when he was in fact referring to reading the fine print. I also somehow managed to skip over the text after the big image, which would've revealed my error before posting. In short, we all agree on the subject.
The Extreme9 also has a 12+2 power phase design, whereas the Extreme6 has 8+2. If I'm not mistaken, the heat load per channel scales pretty much linearly, so that with an 8+2 power phase design each channel has roughly half the heat load than with a 4+1 power phase design. Those extra channels probably go a long way in managing an FX-9xxx CPU. I would also expect the VRM section to be built of higher quality components than on lesser boards. Combining all this with that larger heatsink, it might even be possible to run those beasts on this motherboard without spot fans on the VRM. Strong emphasis on the word "might", though. ;) ------------- Ryzen 5 1500X, ASRock AB350M Pro4, 2x8 GB G.Skill Trident Z 3466CL16, Sapphire Pulse RX Vega56 8G HBM2, Corsair RM550x, Samsung 960 EVO SSD (NVMe) 250GB, Samsung 850 EVO SSD 500 GB, Windows 10 64-bit |
Posted By: wardog
Date Posted: 03 Jan 2016 at 8:08am
Took some serious trawling on AMD's site but I found the instructions included with the 9000 series FX silicon with the included AIO cooler. www.amd.com/Documents/FX-9000-Installation-Guide.pdf Boys, we have a Winner in AMD. Kinda sorta ....... loose wording but does mention cooling the VRM section. At minimum at least AMD is Intimating possible heat issues. Too, I appreciate AMD keeping tabs on just what motherboards are certified to handle/cool/power the 220W FX silicon and frequently updating the included instructions. Bonus, so long as one abides by them .......
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Posted By: parsec
Date Posted: 04 Jan 2016 at 1:49pm
There we have it, from the fine (or hard to find) print! Thank you SO much wardog, for finding and posting this information!  IMO, the link to the FX-9000 Installation Guide should be included in a sticky post in the AMD Technical Support forum. It may not be what some people want to know, but it is what they need to know. This statement alone warms my heart: "AMD FX 9000 series processors feature a 220W TDP and have three unique requirements:" They used the 'R' word, Requirements.  Some of the wording may be loose, I agree, but IMO there is one big ambiguity: 2. A socket AM3+ motherboard that supports processors with a 220W TDP. What is it about an AM3+ board that allows it to support a 220W TDP processor? Let the arguments begin. I will try to stay out of that. The point most dear to me personally: 3. Chassis exhaust fan mounted near the motherboard VRM components with at least 35CFM of air flow capacity. Notice this requirement does not take into consideration the heatsink, or lack thereof, used for the VRM transistors. That does not make it something that can be ignored. These requirements are kept at a high level, meaning lacking details. Still, they are not just very important. They are requirements. If you do not fulfill these requirements, and have problems, the fault is yours. The only thing I would question, in theory shall we say, is why is only the 990FX chipset implied as a requirement. I know why it is to some degree, but I don't know why it would seem it is the only chipset worthy of use with a 220W TDP AMD processor. ------------- http://valid.x86.fr/48rujh" rel="nofollow">
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Posted By: wardog
Date Posted: 04 Jan 2016 at 4:52pm
It's not the 990FX per se but instead when the 220w CPUs fiirst made their appearance the CPU was designed "for' the 990FX. That the silicon uses 220w, at the time manufacturers needed to beef up the power delivery, straighten the socket traces along with lowering them in the boards substrate layers to shield, and IIRC keep the area surrounding the socket free from SMD and other surface circuitry. That above only covered the electrical side, never mind delving into the finer points of difference between, say, a 970 chipset, versus the 990FX's. ie: 990FX's chipset TDP, no. and configuration of PCIe lanes, HT speed, etc etc The design specs req'd for a 220w processor come together to give the end user a great experience. Hence so few boards from which to choose. A complete redesign. |
Posted By: wardog
Date Posted: 04 Jan 2016 at 4:55pm
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Too, there are major differences between the 990FX and the 990X that AMD chose to state only boards with the 990FX. |
Posted By: wardog
Date Posted: 04 Jan 2016 at 5:03pm
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If you'd like I can write up a post for consideration of being made a Stcky. PM me your thoughts. |