Big Heatsinks

[Mustang]

Re: Big Heatsinks

Here's a few more things to consider in order to drop temps a bit. Lap the mating surfaces of the cpu and the heatsink. They're not very flat (in most cases) from the factory and can net you at least a few deg C in temperature drop. It's also very important to use a minimum of thermal compound when both surfaces are flat and smooth. I go from 400 to 1500 grit wet or dry automotive sandpaper lapping wet with a bit of detergent. It really helps a lot. Also, moving cables and wiring out of the way really helps airflow and decreases turbulence.

On the aside, there's 2 silly designs in most modern tower cases that should be rectified. 1st, the power supply should be mounted at the bottom of the case so it doesn't have to suck in hot air as well as generating it's own. 2nd, video cards are mounted upside down IMHO. All that heat from the GPU gets spread out along the bottom of the card heating it up unnessesarily. There's not to much that can be done about those issues though.

[Per Hansson]

Re: Big Heatsinks

Mustang; Yes there are such cases, the Lian-Li PC-V1000 for example;



(Picture stolen from this review; http://www.dansdata.com/pcv1000.htm)

[Mootsfox]

Re: Big Heatsinks

But at what voltage? And is it prime stable? I know my QX9650 I had to fight it to get it to 4GHz, and this is with a Vapochill LS. I had to slightly exceed Intel's VID value for the chip! Yes, you can overclock 'em to obscene speeds, but you need IMHO dangerous voltages to do it, especially with 45nm.

Get this... 1.25v!

They seem to do about 3.7-3.8 on stock voltage, which I believe is 1.125v. Keep in mind that these chips have a spec'd range that goes up to 1.3625v.

I have a Q6600 myself, and while I can do 3.3 on stock voltage, I can't get over 3.64 with 1.575v. I'm on air, though.

[starfury1]

Re: Big Heatsinks

Thats borrowed Per and you paid him by giving him a link

BTW anyone got some comment on have the psu at the bottom of the Case..?

[acstech]

Re: Big Heatsinks

Get this... 1.25v!

They seem to do about 3.7-3.8 on stock voltage, which I believe is 1.125v. Keep in mind that these chips have a spec'd range that goes up to 1.3625v.

I have a Q6600 myself, and while I can do 3.3 on stock voltage, I can't get over 3.64 with 1.575v. I'm on air, though.

It seems kind of hit or miss. Most I've seen take more than 1.25 to do 4GHz with stability. See here:

http://www.xtremesystems.org/forums/...d.php?t=173999

Also keep in mind that a lot of those guys go for the suicide shot and never bother with stability, or if they do it's very short duration, so you kind of have to weed some of them out.

[gonzo0815]

Re: Big Heatsinks

I think PSU on bottom is the way to go, so any heat producer can just cool themselves, without interfering air streams.

The Arctic Cooling cases are designed in the same way and are very good cases (apart the custom made PSU).

[Mootsfox]

Re: Big Heatsinks

It seems kind of hit or miss. Most I've seen take more than 1.25 to do 4GHz with stability. See here:

http://www.xtremesystems.org/forums/...d.php?t=173999

Also keep in mind that a lot of those guys go for the suicide shot and never bother with stability, or if they do it's very short duration, so you kind of have to weed some of them out.

http://www.overclock.net/tankguys-pr...c-testing.html


Keep in mind that these chips are rated to 1.3625v. Just like the 65nm's are rated to 1.5v.

[acstech]

Re: Big Heatsinks

Nice engineering sample. See the first pic in the link I posted.

[davmax]

Re: Big Heatsinks

Great CPU-Z pics. Overclock is great (19.6%) but memory speed and timing is slow and limiting for CPU. eg See my signature the DDR2 800 is 4.4.4.12 and will overclock to 960 reliably. The E6420 runs all day cool at a similar 20% overclock it appears that it could be pushed much harder but I feel that I have good value and I want it to last.

[grss1982]

Re: Big Heatsinks

A bit OT, but I've got a generic case that has:
2x80mm@front
1x80mm@side panel (center of side panel to be exact)
1x80mm@rear

Now I was wondering what's the ideal set up for this kind of a case? (Take into consideration that I have a Dual Fan Enermax PSU with 92mm & 80mm fans.)
OPTION A = 2x80mm@front as intakes
1x80mm@side panel intake
1x80mm@rear exhaust

OPTION B = 2x80mm@front as intakes
1x80mm@side panel exhaust
1x80mm@rear exhaust

Any ideas on which of the two would be optimal???

[acstech]

Re: Big Heatsinks

Davmax: So you're running about 320 for the FSB then? You'll get better performance if you can lower the CPU multiplier, set your mem to FSB ratio to 1:1, and raise the FSB. You may however be limited on how far your CPU will accept a high FSB.

Keep in mind also those pics I linked are not my own. Mine (the QX9650) is running 445x9, DDR2-890, 4-4-4-12 2T, on Kingston value ram, at 2.0v. And it will go higher. I need to experiment with lowering the CPU multiplier, loosening the timings, and raising the FSB some more. Right now I think it's kind of a bottleneck for the quad core.

The thing I've found over the years is that Kingston value ram will usually clock just as high, with the same timings, as their Hyper-X stuff, if you give it the same voltage.

Edit: You posted while I was typing! I favor Option A, since then the side duct fan wont be fighting the CPU fan.

[grss1982]

Re: Big Heatsinks

Edit: You posted while I was typing! I favor Option A, since then the side duct fan wont be fighting the CPU fan.

That's what I thought as well. Although I'll be modifying it a bit by using a 120mm to 80mm fan adaptor on the 80mm hole at the side panel. :-)

Sucking in air using the power of a 120mm fan.

[gonzo0815]

Re: Big Heatsinks

The problem with those Enermax dual fan design is, that they put the most air back into the case.
So either some modding or extra exhaust fan are required.

[starfury1]

Re: Big Heatsinks

Thanks Gonzo for your thoughts on the bottom mounted PSU.

[grss1982]

Re: Big Heatsinks

The problem with those Enermax dual fan design is, that they put the most air back into the case.
So either some modding or extra exhaust fan are required.

How about we cover those vents opposite the exhaust fan? would that help prevent hot air from being re-introduced into the case?

[PCBONEZ]

Re: Big Heatsinks

Duct tape.
Electric tape.
Piece of sheet metal with rivets, screws, liquid nails, (or soldered as like used for copper pipe or radiators.).

[Bookworm]

Re: Big Heatsinks

To respond to one of the first questions.

Board warping: This generally isn't that much of an issue, but if you're concerned about it, put in some rubber standoffs.

I have several bags of them from when my mother worked at Compaq.

[willawake]

Re: Big Heatsinks

Mustang; Yes there are such cases, the Lian-Li PC-V1000 for example;

and the Cooler Master CM 690
http://techgage.com/article/cooler_master_cm_690/1
http://www.virtual-hideout.net/revie...90/index.shtml

[willawake]

Re: Big Heatsinks

and the
Lian-Li PC-A70B
http://hardwarelogic.com/news/135/AR...007-08-21.html
with option at top or bottom or both





*wants

[PCBONEZ]

Re: Big Heatsinks

I've actually put feet on the top of a case and flipped it upside down.
Then cut and stained a piece of oak to make the bottom look pretty on top.
-
It gets the PSU on the bottom but that wasn't my goal.
I like the optical drives below eye level when the case is on the desk.
.