Lian li PC-75 case mods. Should I or not.?

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Hello, I'm planning to purchase a Lian Li  PC-75 tower case for my new
system that I'm planning to build. I will include the following.

1. MSI K8N Neo4-SLI motherboard
2. AMD Athon 64 3500+ cup (Winchester core)
3. Corsair XPERT TWINXP 1024 3200XL DDR 400 1Gig
4. 2x Chaintech SE6600 Geforce 6600 GT PCIe video cards
5. Silverstone Zeus ST65ZF 650 w PSU
6 2x Western Digital 74D Raptor 74 Gig HDD (Raid 0)
7. Western Digial caviar 74 gigabyte 7200 rpm data backup HDD
8. Plextor PX-716A DVD Writer

I need to know about whether or not I should get certain modifications such
as a blowhole for a 120mm fan in the top of the case. and also whether or
not it would be advisable to get a cutout for a UV fan in the clear acrylic
side panel. Of course I'm concerned about heat build-up inside the case
running a SLI game rig but I've heard that aluminum cases such as the Lian
li PC-75 are good heat dissipaters by themselves so please give me your
input regarding this matter. Your prompt replies will be appreciated.

Thank You

Re: Lian li PC-75 case mods. Should I or not.?

On Tue, 17 May 2005 21:42:26 GMT, "Nospam"

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Probably not, it among the least effective ways to go.
Moving air in or out without it passing by hot components
will alter the flow rate in other areas.  If it were exhaust
it significantly reduces PSU and rear case exhaust.  If it
were intake it significantly reduces front HDD & video card
cooling.  It's not impossible for it to help BUT is best
left as an option in conjuction with (only after) other mods
are done first, which would be more signficant and likely
eliminate any further cooling issues.

On the other hand, if it's not expensive you could have the
hole and shut off the fan or seal it later... your call.

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No it'd be advisabe to get a cutout for a good-quality
regular fan in the clear acrylic side panel.  That is,
unless suddenly a decent fan manufacturer has started making
clear fans.  Ideal would be a Panaflo with voltage-reduction
to reduce noise/wear/dust.  That fan's placement should be
low enough and far enough towards the rear to get some flow
under/inbetween the video cards.  When using a side-intake
fan it's even more important to have good front intake so
the increase in pressure from the side fan doesn't
excessively decrease intake through the front.

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No, that's a an unfounded urban legend.  Aluminum only
impacts cooling across significantly higher temp
differentials, and in this situation the only high-contact
area is with the air.  Cooling is dictated by removal of
heat by immedate contact of metals to the heat-producing
objects and the flow rate across them, plus the temp of the
air (oversimplified but Google can provide plenty of info
more than a usenet post).

The biggest different in case construction as it effects
cooling is the allowance for large unobstructed intake and
exahaust areas, especially IF the case is sturdy enough that
the fan mounts can be almost (if not) entirely open and
using at least 92mm, preferribly 120mm and thickest possible
fans.  You can get by with smaller diameter fans, it'll just
be quite a bit louder per same flow rate.

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Same situation as most cases, have front bottom intake
that's as unimpeded as possible.  Same with rear.  If rear
exhaust rate isn't high enough and you can't open up the
front intake any further then a front fan is needed.  A
front fan may be needed regardless if the drives are densely
stacked.  Take temp readings and touch-test parts where
possible.  When considering specific cases it's good to post
links to pictures of the interior & rear for those not
acquainted with particular model(s).

Re: Lian li PC-75 case mods. Should I or not.?

While I normally defer to kony's expertise, my personal experience with a
Lian Li PC65 case through 3 builds has been that the 80mm blow hole in the
top of the case has been helpful (though it definitely adds noise to the
system). My present system is an AMD64 3200 w/ 2 X 512MB PC3500 @ 2.6V, an
ATI 9800 Pro, 2  X 36GB Raptors (Raid 0), and an IBM IDE Deskstar storage
drive. Additionally, there is a Unibrain Firewire card, a Crystal Fontz LCD,
Plextor DVD/CDRW, a card reader and floppy. The PSU is an Antec 430W. Plenty
of stuff to produce heat. I don't have the side window or any side panel
fans. Two front intake fans (in front of the hard drive cage), one exhaust
fan in the back, the PSU fans (2), and the blowhole.

Everest Home list the CPU temp at 46C, the motherboard at 44C, and hard
drive at 29C.

These temps are fairly constant, and don't increase significantly under
greater loads (like games). One thing I have noticed is that failing to keep
the dust filters in the front of the case clean will raise the system temp.

Re: Lian li PC-75 case mods. Should I or not.?

On Sun, 22 May 2005 21:52:42 -0800, "Fitz"

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Perhaps I didn't word what I wrote well...

Adding fans can certainly lower temps, but the remaining
question is still whether the particular subsystems needing
cooling, are cooled most effectively (and at best cooling vs
noise and dust ratios) with any particular fan placement.  

So long as the overall case pressurization is kept at the
desired level one can add fans to their heart's content...
but the specific system and case must be considered if one
is to maximize cooling to noise ratio... anytime I mention
adding fans it is always within the context of their being
especially low RPM and not adding significantly to the noise
of the system (unless stated otherwise).

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