Coolermaster 610/620 HTPC case owners: airflow warning

wumpus · Post by **wumpus** » Sun Apr 11, 2004 9:14 pm

I've always had ongoing temperature issues with my Coolermaster 620 HTPC case. It drove me crazy trying to figure out why this PC...

..was running so hot. I tried dozens of solutions. In retrospect, the primary reason was right in front of me all along-- the case is starved for air. This is probably common for HTPC enclosures; a cool, clean "giant slab o' aluminum" front panel does not leave a lot of room for air intake!

Why did it take me so long to determine an answer that seems obvious in retrospect? Well, temps weren't always that bad. I upgraded this box to an Athlon 2500+ recently, and temps were never really great, but not terrible enough to be concerned about (~70c load). However. I later had an unrelated problem* that caused CPU temps to spike to ~85c under 100% load. 70c is fine as a rare peak, but 80+c? That's a bit too hot for my blood.

In the process of investigating the cause, I tried running the exact same configuration in two scenarios:

with the cover off... 55c load.
with the cover on... 85c load.

Uh, yeah. 30c difference with the cover on? That's a case which is starving for air, big time! The only front vents in the entire system are here, on each side:

What I did was tin snip across the edges to make this one giant square hole. That sounds ugly, I know, but I dremeled the edges even and I used this clever wire mesh mod to cover the hole, while retaining dramatically improved airflow:

End result? 61c under load. Now, NOT all this is attributable to the airflow improvement*, but when you have a system that shows a 30c rise in temps between cover-on and cover-off, that's absolutely symptomatic of air starvation. The other way to benchmark this would be cover-off load temp (~55c) compared to cover-on load temp (~61c).

* This machine uses a SLK-900. Thermalright SLK-style heatsinks with those rows of tightly spaced copper fins perform HORRIBLY when the air is not blown horizontally over them. I had a fan with (I swear) a modest 5 degree tilt blowing air on the heatsink, which caused these insanely high 85+c load temps in the first place. Before the fan angle change, load temps were around ~71c.

lenny · Post by **lenny** » Sun Apr 11, 2004 11:52 pm

I have an ATC-600 that was also starved for air (acrylic panel instead of aluminum in the front).

My remedy is a lot less drastic than yours, since I cringe at the thought of damaging the finish on the case.

System : P4 2.66 GHz, ATI 9800 Pro.

I removed all the case fans. Got a Fortron 120mm PSU and Arctic Cooling VGA Silencer for exhaust. I think the ACVS made a real difference because exhaust air from that is much hotter than exhaust air from the PSU. Previously the surface immediately above the graphics card is quite warm. Now it's much cooler.

I could feel with my fingers air being sucked into the case through each of the 3 vents. I've no doubt temps will be further improved if I open them up some more. But temperatures are acceptable for now. If I'm still using this case in the summer, I'll probably try leaving a PCI slot cover off.

Fabool · Post by **Fabool** » Mon Apr 12, 2004 12:11 am

I have a 620C case here and it's running fairly hot but not as hot as yours. I get somewhere around 60C under moderate load (P4 2,8Ghz 9800pro with vga silencer) but I do have to run the fan on my Thermalright SP-94 at 12v for it to remain that cool. What worries me are the motherboard temperatures which hover around 50C.

Haven't really found a good solution for cooling the case, my latest one would involve the passive Zalman Reserator 1 external watercooling unit but I'm not sure if I'll end up trying it or not. Adding more fans to say behind the grills isn't an option since the case already sucks in way too much dust for my liking. Also, I definetly am not going to try and cut the case, it would end up looking horrible with my skills.

wumpus · Post by **wumpus** » Mon Apr 12, 2004 7:27 am

My remedy is a lot less drastic than yours, since I cringe at the thought of damaging the finish on the case.

Yeah, I know. It's a very nice paint job on the case. If you are careful with the snips and dremel the edges flush, it comes out looking stock though.

I pretty much had to do it on mine.. changing from the Fortron 120mm to the Seasonic 120mm reduced air flow quite a bit from the power supply. This is the only case I had that would work with the Seasonic, I have one of the "fan won't start reliably when PS is mounted with the fan facing down" models, and this case is the only one I have where the PS mounts with the fan facing up.

I also have a very low RPM 60mm fan mounted in the rear. Again unavoidable, due to ultra-low power supply outflow.

All of these "solutions" are really not getting to the source of the problem, though: the horrible intake airflow situation. Until that is addressed, there's only so much you can do..

I get somewhere around 60C under moderate load (P4 2,8Ghz 9800pro with vga silencer) but I do have to run the fan on my Thermalright SP-94 at 12v for it to remain that cool. What worries me are the motherboard temperatures which hover around 50C.

What you and lenny should try, is comparing cover-off temps with cover-on temps. That'll give you a good baseline of what the possible improvement could be, without changing anything..

Fabool · Post by **Fabool** » Mon Apr 12, 2004 9:14 am

I did try running the computer without the cover some time ago and if I recall corectly the temps dropped 5-10C on the processor and the motherboard temperatures were under 40C.
I also have a 80mm Nexus fan mounted with an 60-80 adapter inside the case to the 60mm hole. The PSU is a 120mm fan model.
Can't really see anything more I could do to make the temps better without modding the case or trying watercooling.

Post by **Rusty075** » Mon Apr 12, 2004 10:06 am

What about adding intake holes on the bottom? (a la the DVine 5) It wouldn't be as effective as a big honkin' intake on the front, but a row of holes along the front edge of the bottom panel would add much needed intake area.

Plus it wouldn't affect the appearance. (and any poor workmanship would remain safely hidden

)

wumpus · Post by **wumpus** » Mon Apr 12, 2004 6:39 pm

Hey, that's a good idea. Fabool and Lenny, give that a shot. No way you can damage the appearance with a bunch of holes drilled in the bottom.. and I guarantee you'll see a big improvement in temps with such an air-starved front panel.. why it's almost Sonata-esque..

PretzelB · Post by **PretzelB** » Tue Apr 13, 2004 8:30 am

And I thought my Antec Overture had problems. My temps never got as bad as you guys but I only have a 1.4 amd cpu at the moment. I like the idea of the bottom holes, I may try that myself.

One thing I did try on my Overture might help. I glued some angle brackets to the top cover of the case and attached an 80mm L1A to it. The fan blows air out the back and gives the video cards a slight breeze. I also removed the unused back pci slots and moved my cards to either side. The idea was to encourage hot air out of the case.

To be honest, my idea didn't work all that well. My case temps did drop from the 40's to the 30's but the cpu temp remained in the 50 range. If I did some duct work it might help but I'm leaving it alone for now. You might get better mileage out of this idea because your case has more space for hanging fans.

Actually, this idea would probably work in regular tower cases also.

wumpus · Post by **wumpus** » Tue Apr 13, 2004 9:06 am

My temps never got as bad as you guys but I only have a 1.4 amd cpu at the moment.

Right, you can limp by with crappy case airflow for lower power CPUs.. but as the heat dissipation goes up (faster CPUs), the low airflow becomes a serious problem.

Plus, the better the airflow in your case, the lower RPM fans you can use, so it's ultimately better for noise no matter what heat level your CPU produces.

Fabool · Post by **Fabool** » Tue Apr 13, 2004 9:16 am

If I drilled holes to the bottom of the case wouldn't that also increase the amount of dust which gets sucked in?
I don't know why, but the case as it is sucks in a huge amount of dust in a short period of time, so I wouldn't want to increase that if possible, since cleaning the case is always a bit of a hassle. Filtering the intakes wouldn't probably matter much as it would just restrict the airflow as well and I'd be back right where I started.

wumpus · Post by **wumpus** » Fri Apr 16, 2004 12:38 pm

Dunno about dust-- I've never had a serious dust problem in any of my systems, so I don't see the need for filtering. Besides, it's nothing a tri-monthly application of cmpressed air can't fix!

(try to imagine the above vent as just a square open hole after careful tin snip application)

I finally got around to dremelling the vent edges flat. This is definitely a semi-advanced "finishing" mod, because you have to be quite careful around the nice paint job. That said, it can be done. I found that using the flat circular cutting disc worked best, both for cutting stragglers and finishing the edges-- just push it downwards against the straight borders of the square hole and it cleans up nicely.

The paint job on the side doesn't really get damaged, unless you accidentally slip with the dremel. There is of course the issue of the edges of the vent hole, which do show some exposed aluminum. To clean this up, I used an idea my wife had-- go figure. A black sharpie. Doesn't really have to match the paint exactly, because it's not on the same surface.. just removing the visible silver is enough.

As for covering the now-exposed gaping vent hole, The wire grille mod (see first posts) worked grea! It's quite easy to cut this stuff with just a nice pair of scissors.. no snips necessary. I used foam tape round the inside edges, applied the cut wire mesh flat, and voila!

The end product isn't PERFECT, but it would certainly pass close inspection by a layman as "stock". I give it a B for looks, and an A+ for dramatically improving my CPU load temps