Case mods & airflow

Merlin · Post by **Merlin** » Thu Jul 15, 2004 8:25 am

I figured I had better start a new thread since the subject has changed. I have been thinking about an idea and wanted to bounce it off you guys. My thoughts are that the connectors to all,or most, of the ICs attached to a MOBO protrude out the back side of the board and have solder points on them but there is almost no air circulating between the MOBO tray and the MOBO. I thought if it were possible to have a funky funnel made out of plexiglass that would basically be flat like a book and thin enough to line up with the front of the MOBO and have a 40mm, or so, fan attached to the other end that would circulate air thru the 1/4" gap between the MOBO and its tray. You could then Drimmel or cut several slits in the back of the tray that would provide an exit for the hot air and vent it out of the case via another fan on the right rear of the case door. I don't know if this has been tried or not but I have a friend that owns a custom plexi shop and he can fab almost anything out of plexi (the router table I spoke of is his). Do you think that any benefit can be had by moving cool air behind the MOBO and would the setup I described move enough air to help?

Post by **Apoptosis** » Thu Jul 15, 2004 9:04 am

When I was in Taiwan I saw a lot of R&D (research & development) that dealt with cooling the motherboard from the backside.

A prime example of companies seeing how well it works is ASUS. ASUS has come out with Stack Cool which is basically another PCB with nothing on it attached behind the board. There is a small gap between it and the motherboard and heat sensitive parts (MOSFETS, Capacitors, & so on) have been soldered to it.

ASUS Stack Cool:

Close-up Of Stack Cool:

So after seeing companies start to use methods like this to cool the motherboard by drawing heat out to the rear I believe cooling the backside of the board should prove succesful if done correctly.

Merlin · Post by **Merlin** » Thu Jul 15, 2004 12:30 pm

I also thought about removing as much of the metal that makes up the tray as possible without weakening it too much. I guess its a matter of trying it out and seeing what works. I have to get my temp monitoring problem fixed first so I can document any temp changes.

Post by **Apoptosis** » Thu Jul 15, 2004 2:43 pm

yeah.. you'd almost have to do something like ASUS to help pull the heat away from the board by attaching something. I'm sure that by openeing the back up and providing air circulation would help some & actually maybe more than one would think. Maybe put a thin case fan blowing in from the right side panel onto the back directly?

infinitevalence · Post by **infinitevalence** » Thu Jul 15, 2004 3:37 pm

One of the features of the case that Capper bought, the Coolmaster Stacker, is the "Cross flow blower" a fan that is set to blow air across the front and back of the motherboard to cool it.

LVCapo · Post by **LVCapo** » Thu Jul 15, 2004 7:16 pm

Actually Infinite, it is only set up to blow across the front, the complaint with it is that it just blows onto one side of the ram. But there has to be a way to mod it so it can hit the back

Merlin · Post by **Merlin** » Thu Jul 15, 2004 8:02 pm

Maybe one of those PCI slot blowers mounted to the drivebay chasis. How much airflow do you think would be needed in terms of CFM?

Post by **Apoptosis** » Fri Jul 16, 2004 10:33 am

20-30cfm would be my guess... otherwise you'll get a lot of noise

infinitevalence · Post by **infinitevalence** » Fri Jul 16, 2004 10:40 am

That would be plenty because your not going to get that much of a drop in tempretue with out some kind if sink any way.

Merlin · Post by **Merlin** » Fri Jul 16, 2004 11:08 pm

Hey Capper, I don't remember, in the coarse of our conversations, if you responded to my idea of the fan shroud in the front of the Wavemaster as well as drilling out the front holes in the case to inprove air intake. What do you think?? I am trying to get more air into the case without adding any externally visible holes if it is possible. I will cut holes if you think that is the only way but I don't really want to.

LVCapo · Post by **LVCapo** » Mon Jul 19, 2004 10:29 am

Sorry Merlin, busy this weekend working on a case.
As to the wavemaster. Instead of cutting holes, if thats important. I would replace the stock fans with good fans, to me the stock fans just ddin't move anything. I would also replace the top I/O port with a fan to pull the warm air out the top..
After doing this, if you found that you case temps still weren't good, then I would consider cutting a hole and mounting a fan on the case side panel. Just do it in steps, getting a little more extreme each time until you get the desired results.

Merlin · Post by **Merlin** » Mon Jul 19, 2004 11:34 pm

Hey Guys,
If I have my door off will the temp that I read this way basically be the absolute minimun temp I can reach with the heatsink/fan combo no matter what I do to the case?

LVCapo · Post by **LVCapo** » Tue Jul 20, 2004 3:48 am

For the most part, yes. The only other thing you can do that might help is to somehow mount a fan which forces air onto the board.
For example, I ran my Cooler Master with the door off, and felt that there were a few hotspots on the board I was worried about. So I drilled two holes in the PSU cage and mounted a 92mm fan which blew air onto the heatsink/fan as well as the mosfets. Did it help? yes. Was it a big difference? Who knows. I think that working with the case door off is the best possible scenario in that it will give you as much cool air as possible

Merlin · Post by **Merlin** » Tue Jul 20, 2004 6:02 am

As you had said earlier I wanted to see what temp I would be able to get with case mods. I'll wait till I can get an accurate temp reading then I'll let you know where I go from here. If my system/case temp only goes up a few 'C when I put the door on then holes and fans are pretty useless.

LVCapo · Post by **LVCapo** » Tue Jul 20, 2004 6:39 am

I agree, make sure you test it under load, not just at idle. i think you'll find 5-7C is about normal. It is an appreciable difference. I just finished putting together an AMD 2500+ mobile. It idles at 43C/24C running 2.5GHx. If anyone is looking for a great O/C chip. i highly recommend the Barton 2400-2600+ mobile CPUs, unlocked multipliers, and they run real cool.

Bio-Hazard · Post by **Bio-Hazard** » Tue Jul 20, 2004 7:22 am

When I was air cooling my system, my CPU ran 1-2c hotter with the case door off. Removing the case door interupts the air flow within the case. If set up right, your case and CPU temps will be cooler with the case in one piece...........

Capper,
Glad to see that you've taken a walk on the wild side.........

with AMD. What are you cooling your XP-M with, your temps seem to be a little high. My second system (also 2500 locked) runs pretty cool on air, Thermalright SLK800 with Thermaltake Smart Fan. Temps are case-25c, CPU Scoket-37c, CPU Diode-47c. The system will be getting my old Corsair Hydrocool as soon as my other system is finished.......

infinitevalence · Post by **infinitevalence** » Tue Jul 20, 2004 8:12 am

Thats a little high but not unusual for an overclocked xp, plus he is runing almost a ghz over stock at +.5v.

Bio-Hazard · Post by **Bio-Hazard** » Tue Jul 20, 2004 9:00 am

My air cooled system is running a slight OC of 11x200 @ 1.7 volts. The temps are load running 24/7, running folding @ home and being used as my internet server and file server for home use........... :D It's also me back-up gaming system for when I've got my main system taken apart for one reason or another........

Specs are:
X-Dreamer case (Cheap) 6 case fans
Asus A7N8X
AMD 2500 XP
2x512 Kingmax Super Ram
Thermalright SLK800A, Thermaltake SF II
ATI 9500Pro (Modded to 9700Pro) Artic Cooling VGA Silencer
Lite-On CD
Maxtor ATA133 60 Gig

LVCapo · Post by **LVCapo** » Tue Jul 20, 2004 1:04 pm

I'm using that Thermaltake Volcano. I didn't have the chance to order a Thermalright. This is going to be one of my review systems, so I'll be switching coolers on it frequently. As to the rtemps, it varies alot. If I run no side cover, it runs at 42C, with the cover on it is at 47C. My temps seem about avg for where I'm O/Cing at, and I have to say I'm really impressed with the AMD chip, $80 !!!!! and this thing runs sweet. Still have the memory issue, I have even tried switching out the Kingston with my Corsair (both DDR 500) It doesn't want to boot at anything less than 3-3-3-8....
I have poured over the net looking for help and answers, as this is my first AMD, and they O/C a bit differently.
I also finishe my review on the Thermaltake Tsunami, awesome case, I would definitely recommend it to anyone looking for a midtower, I would also recommend it over the Waver Master case. Hopefully Nate will post the review shortly.

Bio-Hazard · Post by **Bio-Hazard** » Tue Jul 20, 2004 5:25 pm

You need to get some good highend PC3200 that will do 2,2,2,5 and your problems will go away for the most part. AMD likes tight tight timings and doesn't play well with all that high speed stuff with loose timings. PC3200 or at the most PC3500 will bring you the most good.............