Updated VGA Card/Cooler Test Platform

Cooling | Graphics Cards | Reference|Recommended
Viewing page 2 of 4 pages. Previous 1 2 3 4 Next

UPDATING THE TEST PLATFORM

The table below details the old platform on the left column, and the new platform on the right. The fundamentals have not changed; it's still a lean, clean machine with a fairly hot processor and very low airflow. But it runs cooler and more quietly under all conditions.

Old VGA Test Platform New VGA Test Platform
LX-6A19 (D8000) case from Cool Cases with all original fans, metal vent grills, and front intake bezel cover removed. Antec P180 case - This is the very first prototype shipped by Antec for me to examine in late 2004. It has many small flaws and it's pretty badly beat up, but it has all the basic features of the latest P182. There are many mods, described later.
Nexus 120mm case fan at 7V (and other voltages) by custom stand-alone voltage controller. Same fan driven through a custom-built "diobus" zener diode voltage switcher as described by cpemma on his DIY Fan Noise Solutions web site. 12V, 10.5V, 9V, 7.5V and 6.75V settings are available.
Intel Pentium D 930 Presler core processor. Official TDP of 95W. Unchanged - This outmoded processor is actually hotter than average now that energy-efficiency is a real objective of CPU makers.
AOpen i945Ga-PHS motherboard - Intel i945Ga chipset with built-in VGA. Unchanged - It's best to keep the motherboard the same as most of the temperature data comes through the motherboard.
CoolerMaster Hyper 48 heatsink, cooled by a Nexus 92mm fan undervolted to 7V. Gigabyte G-Power 2 Pro heatsink, stripped of its original fan and shroud, and fitted with a Scythe Slip Stream 500RPM 120mm fan. This is a far more effective cooler with at least double the surface area and a fan that's twice as big.
Corsair DDR2 RAM, PC2-6400, 1024 MB Unchanged
Antec Neo HE 430 ATX12V 2.01 compliant power supply, with a custom-built fresh air duct to ensure that the internal fan did not ramp up during testing. Seasonic S12-600 ATX12V v2.0 compliant power supply, modified with a Scythe Slip Stream 800RPM 120mm fan @ 5V. The higher power capacity and efficiency, and much bigger heatsinks should help.
Seagate Momentus 5400.2 120 GB, 2-platter 2.5" notebook hard drive, suspended in a NoVibes III just inside the front intake vent. Samsung MP0402H 40GB 2.5" notebook hard drive, floating in a custom clothing elastic suspension in the bottom

PHOTOS & DETAILS OF NEW TEST PLATFORM

The Antec P180 case has two front 120mm intakes — the bottom one feeds fresh air to the hard drive and power supply section while the top one allows airflow into the rest of the system. The stock filter and door over the intake vent for the main chamber were removed. They were replaced with the metal mesh for the top panel 120mm fan. The filter for the lower PSU/HDD chamber was retainted, but its cover door was also removed to reduce airflow impedance. The front door was cast away as well to improve airflow. The top three optical drive bays are covered with a block of open-cell foam which allows some air to flow in but also absorbs much of the internal sound from coming out. You could say almost the entire front panel is an intake vent.


    The Antec P180 provides the housing for our test platform.
    Some modifications made it better for our needs.

The processor is cooled by a modified Gigabyte G-Power 2 Pro without its plastic shroud utilizing a Scythe Slip Stream 120mm 500RPM fan, connected directly to the motherboard's CPU fan header. This solution is more than adequate to cool the CPU and as a bonus, is completely inaudible. A block of foam is positioned on the ceiling over top fan vent, which also draws some air in when the system is running.


The internals of our new testbed.

The only system fan is a Nexus 120mm mounted in the rear exhaust position with silicon rubber nubs made expressly to reduce vibration conduction into the case. It is powered by the PSU through to a customized fan speed controller using zener diodes. A knob protruding from the wall of foam at the front allows the fan voltage to be easily varied.


The back of our homemade fan controller.

The power supply is a Seasonic S12-600 with the stock fan replaced by a Scythe Slip Stream 120mm 800RPM fan, hard-wired to run at 5V. The fan just barely starts up, and spins extremely slowly, at ~400RPM. The limited airflow going through the power supply is not an issue since it is cordoned off at the bottom of the case far from the CPU, and the intake vent/path are extremely open. The temperature of its intake air is that of the room itself. Air expelled from the PSU is only mildly warm, even during long sessions of high power testing.


Power supply and hard drive compartment.

The notebook hard drive is suspended in the lower drive bay with zip ties and cloth elastic with a 2mm round cross-section. No vibration from the drive can be felt on the drive bay. Foam is attached to both sides of the compartment divider as an extra silencing measure. It helped to reduce a touch of lower frequency hum most likely caused by the main fan exciting the resonance of the enclosed air in the main chamber.

The end result is a three fan system, with the system fan @ 6.75V being the loudest component. The system noise level is only about 19 dBA@1m. For comparison, during the quietest moments in our lab with all the computers turned off, the ambient noise level is around 17 dBA. As the comparison table below shows, the new platform gives us superior CPU cooling (a 10°C improvement) and a noise level reduction of approximately 2 dBA. Not too shabby.

VGA Test Platforms Compared (no external VGA card)
System State
System Fan Speed
Updated Test Platform
Original Test Platform
CPU Temp
SPL
System Power
CPU Temp
SPL
System Power
CPUBurn
7V
39°C
19 dBA
144W
50°C
21 dBA
151W
Idle
7V
22°C
19 dBA
73W
24°C
21 dBA
80W
Idle
9V
n/a
21 dBA
73W
n/a
23 dBA
80W
Idle
12V
n/a
23 dBA
73W
n/a
25 dBA
80W
Ambient conditions: 21°C, 17 dBA. System Noise measured @ 1m.


Previous 1 2 3 4 Next

Reference|Recommended - Article Index
Help support this site, buy from one of our affiliate retailers!
Search: