900D Airflow issue or ?

Taliseth

New member
A while back I started building my new computer, everything new everything old had to go :P Now phase 1 is completed. phase 2 was to fit some water cooling in, however other household appliances decided they needed attention (read they broke and needed to be replaced..) As such my budget dropped drastically, and am looking for a temporary solution to improve air cooling in my 900D

The case seems to have quite a bad thermal characteristic for air cooling. To me it looks like the lack of a positive directed airflow towards the cpu, as the air comes in at the front and just exhausts out wherever it can rather than bring cool air past the cpu. So I was wondering how much the air cooling potential would improve by closing up the back of the case with a panel. I was planning to buy the panels anyway, but more for the looks than for improving thermals.

To give an idea the cpu is a 4790k running at 4.2ghz @ 1.15v. while using the stock intel cooler. if I decide to encode a 3 min 1080p video it will hit 95C (about 70 Watt load). Now I know the intel cooler is bad but this bad? I've seen people with stock cooler do an intel burn test and still stay below 90C. so obviously the case has some thermal issues, and there's no (or nearly no) difference whether i run the case fans at lowest speed (600 rpm) or at maximum speed (1400 RPM). Ambient Temperature is about 25C at eye level. (900D has 3 intakes and 1 exhaust)


If anything is unclear or more info is needed, please ask and I'll explain as best as I can.
 
Well it is designed to be a watercooled case lol

But I've heard that there is poor flow through the front panel intake. I know there are diy mod vids on youtube to rectify said issue.
 
Bill Owen did a front panel mesh mod for the 900D. I never put mine on anyway so it's just the filter.
 
I seriously doubt that the front panel would give any significant losses to airflow. It may well disturb the airflow to make it perceptibly louder but really it's not going to kill the airflow of the case.

Yes clearly the problem here is the stock cooler, it's built to 'just' do it's job and it is doing just that. Especially when you consider that the turbo boost is thermally dependent Intel obviously anticipate them getting hot at times. The 5 degree difference between yours and someone elses run of burn test may be in part down to airflow, but there are other factors like how well the thermal paste is applied and how many volts the chip needs to run stock clocks. And far more significantly what their ambient air temperature was! Run yours in the winter out in a garage and i'm sure you'd get it below 80 lol.


Now anyway your looking for solutions not problems so i'll do my best...

1. Replace the cooler. You can pick up a cheap good looking and well performing cooler very easily and it's going to be a far better way of spending your money rather than cutting up your 900D and adding 'a fan' or something dumb. If your not thinking of overclocking then a little air cooler might do the trick or a H60 something like that. If you want to get it really cold and quiet and get some real overclocking headroom get a H100i/H105/H110 but don't feel there necessary for stock, just have a look at the big graphs on the main OC3D review site.

2. Optimize what you have. This is perhaps requires slightly more skill and fiddling than the other option but could potentially cost you nothing and buy you a few degrees if that's what your after. Firstly reduce the heat being produced by undervolting your CPU, see TTL's overclocking guides for that. Next make sure that you have the best interface possible between your CPU and heatsink, re-apply some quality thermal paste and make sure you don't use too much. Finally set your fans up correctly, an intake in the rear traditionally exhaust position and an exhaust directly above the CPU may be the way to go in such a large case. Far more importantly make sure the CPU fan is plugged into the right socket on the motherboard CPU_FAN generally and make sure at BIOS level that fan is correctly profiled and is spinning sufficiently quickly. If it's just set to 'quiet' or 'silent' that could be your issue, that fan needs to blast round when your CPU's is getting toasty because it's only a baby.

Me personally? Well i'd do both, get a new heatsink and set it up as well as possible for aesthetics and performance. My friend wanted to replace his stock heatsink on really tight funds so he picked up an old Corsair A50 off ebay for £12 I found a spare SP120 Quiet fan and for less than £20 he ended up with a great looking and performing little setup.

JR
 
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It's not the front panel that i'm worried about more like the back panel being made nearly entirely of mesh. meaning that any air coming in can go out wherever it wants. rather than be directed to the top back corner of the computer where the cpu is. as such I assumed the cpu just didn't get enough "fresh" air. there is a fan in the back, near the cpu fan, exhausting, but that will only do so much. So part of the problem is the lack of a decent directed positive airflow, which is proven by the fact that none of the dust filters make a difference as I still get a ton of dust. I can see that the filters do their job, but a positive airflow pressure should ensure very little dust to come inside the case.

I agree that the case is made for water cooling and not air cooling, hence i bought the thing in the first place so i could have 10 or 11x120mm radiator space for cooling with most of the radiators nicely out of sight. I'm planning some covers for the hdd cage area and to add a midplate in it to create 2 chambers. 4x120mm intake and 3x120mm exhaust + psu in that "isolated" chamber should do a good job. But that's not what I was trying to figure out, when I get to that point i'm sure I'll make a few posts about it to get input.

Anyway I was going to say I don't want any expensive AIO's but then again I don't want this huge tower heatsink with fan that could possibly impede the RAM or PCI slots. So bought an H100i, I was quite pleased with an H80i I bought before so I expect good results again. I already have 4 Corsair SP120 PWM fans so if the fans are indeed as noisy as shown on some youtube video's I can always replace them easily.

As to my budget it shrank to about 100 pounds, which is well within the limits of most coolers even high end ones, however no where close the amount I would need for the custom water cooling loop I had planned. Although 100 Pounds I really should say Whatever gets me decent cooling between now and my water cooling loop upgrade.

As to optimizing what I have, I've been quite busy so until now I've only reduced the voltage and the speed of the cpu a little. perhaps this weekend I'll be able to gain some more progress. Although I'm hoping the AIO will ensure I can set it back to normal speed with adjusted voltage of course.
 
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Well I received the H100i, not happy. I suppose this thread can be closed.
As this issue with it belongs in the Watercooling section...
 
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