Here's my latest iteration of a quiet PC.
I was getting bored with my PIII-S rig so I decided to see how quiet I could make a P4 800MHz Canterwood system. I wanted a fast, stable sytem to use as my everyday computer. I went with an Intel MoBo for stability.
- Intel D875PBZ Motherboard
- P4 2.4C CPU
- Thermalright SLK900U heatsink + 92mm Panaflo L1A "BX" rpm monitoring fan @ 8 volts via Zalman Fanmate
- 2 x 512MB of Mushkin Level II Dual Pack PC3200 RAM @ 2-3-3-6
- ATI Radeon 8500, fanless
- Seagate Barracuda IV, 80GB
- Toshiba SDM1612 DVDrom
- Nexus 3000 PSU
- Antec SLK3700 case with 120mm "OEM" Panaflo @ 5 volts as case exhaust fan, 92mm L1A @ 5 volts as HDD cooling fan
Here's some pics:
All IDE cables and wiring routed neatly for maximum airflow and minimum clutter. Fans mounted with elastomer fan mounts:
Wiring details. Main PSU wire bundle is covered with gray Flexo-pet from SVC.com. Other PSU wiring is covered with black Flexo-pet from Fry's:
MoBo wiring details. All wiring run as neatly as possible for maximum airflow. Note the unusal shape of the fan blades on the 120mm OEM Panaflo:
Back panel fan mount details. Grill cut away for best/quietest airflow. Rubber molding applied to clean up edges. Fan mounted with elastomer grommets for lowest possible noise. This is a special (non-catalog, as far as I can tell) OEM version of a Panaflo L1A. It is quieter than an L1A at 12, 7 and 5 volts and seems to flow as much air. Case temps stay the same whether I use this fan or a real L1A. (Maybe the funny blade shape has something to do with this??):
My plan was to try and make this as quiet as possible but keep CPU, case and HDD temps well within a safe range. I started with the SLK900U for three reasons. First, it seems like this is the King Of The Cooling Hill for P4 heatsinks. Second, it bolts to the MoBo for the best possible contact and safest mounting technique. Third, you can swap fans to achieve the best cooling vs. noise ratio. I wanted to use a 92mm fan so that it would overlap the heatsink and blow air on the MoBo and RAM. I figured whatever extra cooling I could get for free could only help. I chose the 92mm Panaflo L1A as a starting point and got myself one of those "BX" (rpm monitoring) versions so I could monitor it's speed by plugging it into the MoBo header. I put the fan on a Zalman Fanmate so I could adjust the voltage on the fly for the best possible noise vs. cooling ratio. Default fan speed at 12V is around 2100 rpm. I set the Fanmate to give me 1700 rpm to start. This knocked the edge off of the noise of the L1A. I used 2xPrime95 to load the CPU(s) to 100% so I could check the temps at full load. I monitored the temps with Motherboard Monitor. Idle and load temps at 1700 rpm were quite low so I turned the fan speed down to 1500 rpm and tried again. Temps were perfectly suitable at this setting so this is where I stayed, for now. It's been getting up into the mid 90°F range inside my house over the last few weeks and my system temps get fairly warm in those temperatures.
Here's my final (for now. When it cools down again I'll set the CPU fan speed lower) temps:
Ambient temps in my computer room range from the mid 70°F to mid 90°F range during this time of the year. All temps wil reflect this spread.
- Mobo temp ranges from 28°C to 36°C at idle, 31°C to 41°C at load.
- CPU temp ranges from 30°C to 39°C at idle, 41°C to 51°C at Prime95 load.
These are perfectly safe temps and this computer runs super quiet at these settings. Even when the temps are at their hottest, the PSU fan does not increase it's speed. I guess it's still below it's 200W/38C threshold.
I'm super-impressed with how this rig turned out. It's just a tiny
bit louder than the PIII-S rig that previously resided in this case but is a waaay more powerful system. I've gained lots of performance at the cost of only a tiny bit of added noise (from the 92mm L1A CPU fan running at apprx 8 volts. Come winter I'll turn it down some more and be back where I was with my PIII-S system). I'd consider this new P4C rig a complete success.