Case airflow question

Scougar · 3 Feb 2011 at 08:44

Background: I've just installed a G0 Q6600 and I think it should be running cooler than 75C when it has 1.34V (1.30V on load) @ 3.4Ghz. I reapplied paste last night and it's actually made things about 2 degrees worse (Artic Silver 3).

The Setup: I have a CM Hyper 212 with two 120mm CM Sickleflow fans running at about 1850 in the push/pull config, which is blowing directly on the rear fan (about a 3cm gap to the rear fan). The rear fan is an Akasa Amber 120mm that is only spinning at 1300RPM (roughly).

The Questions: Do you think that the rear fan is significantly affecting the ability of the HSF to shed heat from the case? If so, do you think changing the fan to something better (Akasa Apache for example), will help things a fair bit?

Scougar · 3 Feb 2011 at 11:32

OK, I will try that then with the side off

I will have to try and get some reasonable stuff. I'd prefer to try and get non-conductive this time round.

Scougar · 3 Feb 2011 at 12:52

Will keep my eyes out for MX-4 then or something similar.

Definately need to change that rear 1300RPM fan

Scougar · 4 Feb 2011 at 09:24

The side of the case is certainly not a permanent solution, and definately not one I intend to use long as we have dog's and that means dog hair and dust/dirt.

Scougar · 4 Feb 2011 at 18:21

Do not worry I understood your post. Just did not want to make people think it was 'the' solution. Will try it tonight.

Scougar · 4 Feb 2011 at 22:21

(Room temp has been 22C the entire time.)

Well the results are in... hour running prime 95 with case side on: 78/77/75/74. Northbridge: 52 C.
Take case side off, and continue running: 70/70/66/66 (but mostly below 70). Northbridge: 43 C.

So basically as much as 8 C off the CPU by taking the side off, and I did see the northbridge at 42C so 9/10 C off the northbridge.

My Front case fan is this: Akasa Apache:
Application: PC case or heatsink fan
Dimension: 120 X 120 X 25mm
Fan speed: 600 -1300 RPM
Max airflow: 57.53 CFM (97.74 m3/h)
Max static air pressure: 2.64 mm H2O
Noise level: 6.9 -16.05 dB(A)
Current rating0.33A
Voltage rating: 12V DC

My rear case fan is: Akasa Amber:
Application: PC case or heatsink fan
Dimension: 120 x 120 x 25mm
Fan speed: 1400 RPM
Airflow: 44.8 CFM (75.9m3/h)
Fan air pressure: 1.1mm H20
Noise level: 18.0 dB(A)
Current rating: 0.08A
Voltage rating: 12V DC

Also, to answer a question, my temps on the CPU got 2 degrees worth after reapplying using the 'pea' method. I use a little less than a pea, which seemed real excessive to me, and the temps got worse. I think I will try reapplying with the grain of rice method to see if that helps, and also buy some MX-4 when I get the money.

Scougar · 4 Feb 2011 at 23:22

perhaps just using too much then.

Scougar · 5 Feb 2011 at 21:16

In case i didnt mention it, the push/pull fans on the cpu are CM Sickleflow 2000rpm units.

Scougar · 5 Feb 2011 at 21:44

cameraheaven> The case off DID work, so I can assume most of the heat issues are airflow related. However, I'm not happy with the cpu cooler and I didn't properly clean off the CPU/HSF before the 2nd application as I was trying to stay quiet (baby/wife sleeping) and didn't have anything to hand at the time. I think the old paste, plus too much are too blame.

The 'trick' you mention is common for car's and finding high spot's in bodywork.. so I know where your coming from.

I will consider lapping the CPU and HSF, but first I want to try MX-4 before I do this.

Scougar · 6 Feb 2011 at 00:05

Nice idea, but pretty sure I couldn't do that on this case as it's probably considered a midi-case. The only port I could use would be the rear fan area (due to big HSF), and then the rest of the heat would have nowhere to go from the case.

I'm waiting on a friend to take out his Apache's so I'll give that a go, and reseat the HSF again using less paste and MX-4 if possible. Definately want the temps down, else how else for going further than 3.4Ghz lol.

Scougar · 9 Feb 2011 at 10:15

I am now (once I pay) waiting on the delivery of a Scythe Kama Bay 120mm, so that hopefully I will get a fresh air supply pretty much directly to the Heatsink fans. I'll try it, but I suspect I'll swap out the original fan for something else to increase airflow.

If that doesn't help much, then I'll swap the front and rear fan's to try better airflow, until I get a 2nd apache.

Something else I just thought of.. I may Cut out the original pressed grills as that may help with airflow. Just need to get something to replace the back grill. (The front is covered.)

Scougar · 9 Feb 2011 at 13:22

I'm pretty sure that with 2x 120mm fans on the front the intake will be greater than the exit

Although once the GPU fan get's upto full speed things maybe different lol. I'm pretty certain it's just bad airflow to the CPU cooler now, as a heatpipe cooler with 2x 120mm fans on it should be doing a much better job.

Will need to think of about a blow hole in the top as well, but will need a circular cutting for that,

Scougar · 10 Feb 2011 at 11:42

Hmm.. I'm thinking that there may actually be room in the front of the case for a 140mm case fan if I cut the front intake out a bit. Obviously it'll start adding cost up, but will mean I can swap the apache to the back anyway, and just get a 140mm fan for the front helping with positive air pressure.

I'm also thinking about adding this http://www.overclockers.co.uk/showproduct.php?prodid=WC-034-PB (Phobya 240 radiator grill dual) to the top of my case instead of 'blow hole'. Mainly because I'm sure I can make a neater job with this rather than a a circular hole. Probably will leave it passive to vent to atmosphere rather than adding fans (for the moment). (Obviously this won't help positive pressure though eek! - So probably need some thoughts on it?)

Also as mentioned, getting a very basic 120mm steel fan grill from OcUK for the rear fan to help temps.

EDIT: Am thinking possibly an 140 air penetrator for the main air intake as the air has a fair distance to travel to motherboard/gpu's etc. Does anyone use one as an intake in a "regular" case and can comment on them as this function?

Scougar · 11 Feb 2011 at 09:20

I suppose I could reverse the rear fan, is it a common thing people do?

EDIT: Kama didn't turn up yesterday, so unable to try it out over the weekend. Will have to try next week to see if it helps the temps.

UPDATE: The Phoyba dual grill turned up today from OcUK. A bit bent but should flatten out fine

The rear wire grill also turned up so that's good news. A colleague has lent me a 140mm fan (broken), for fitment purposes to see if I can get the front of the case to take a 140mm fan. Still absolutely no idea how the heck I am going to cut anything out yet as I don't have a dremel lol.

Scougar · 14 Feb 2011 at 12:29

A neighbour said I can use his jigsaw (Apparently ok for metal), to cut the hole I need

So will do that all being well!

The Scythe Kama Bay came today so will be trying that out as well, although I expect to replace the quiet fan with something better CFM wise, or maybe even a penetrator.

Scougar · 16 Feb 2011 at 20:37

Interesting reading chaps

I installed the Scythe Kama Bay today. Didn't have much time as it was after a horrendous start to the day, but got it in there. Currently sat at max of 67 on the hottest core after an hour and twenty minutes and it hasn't budged for the past hour. This is with the case side ON! So basically just as good as with the side off, although it is a few degrees cooler in here at the moment (3 to 4 cooler). The included kama bay fan is pointing directly at the cpu cooler, although I want to change the fan for a better one when possible. It really isn't perfect though as the IDE cable is directly in the air flow so I will have to move my HDD's around or change my DVD rom drive to a sata unit.

The other changes I made where to change the rear fan for an Enermax TB Silence 12cm fan, because I sold all my ambers and had to have a fan on there so this is only temporary. Also I had to remove the fan controller (d'oh) as I no longer has enough spare bay's to mount a 5.25 inch controller in. I will have to find a 3.5 inch controller.

Didn't get a chance to try the blowhole.. not sure I will anytime soon, but will do it when I get a moment without the baby/wife combo that doesn't need me or the PC lol.

Scougar · 17 Feb 2011 at 13:41

That's precisely what I did yesterday with a Scythe Kama Bay 120cm feeding directly onto the CPU cooler. Only downside is I lost my 5.25" fan controller and the IDE cable is semi is directly in the airflow (annoying).

I'm still running a slow fan on the back , so want to replace that soon, which may happen if I can change the front bottom fan to an air penetrator or similar.