Giga Designs M5D-1213Q G-Celerator DUAL 1.33 GHz in a Digital Audio G4

I. Intro & Installation | II. Temps and Cooling | III. System Tests | IV. Graphics Tests | V. Apps Tests


II. Temperatures and Additional Cooling

Temperatures

Since I planned on installing a Seagate Cheetah 15K.3 on an OEM ATTO UL3D, I wanted to monitor the temps. I placed a temp. probe in the gap between the PSU and optical/zip drives cage to get an idea of the air/case temps before the air gets sucked into the PSU. I used Hardware Monitor for S.M.A.R.T. hard drive temps; there's also the freeware Temperature Monitor for this. The stock Maxtor, located in Bay 2 (middle), didn't yield S.M.A.R.T. temps, so that drive is ignored.

I monitored the DA for hours during normal activity and under load, e.g. Cinebench, FCP3 rendering, cloning, etc., both before and after the upgrade. DA was under a table with nothing behind it; so there was ample ventilation. These are max. readings unless range is given.

Temperatures (°C)	733MHz	2 x 1.33GHz
Ambient	22-23	22
Temp. probe	31	40.6 - 41.4
120GB 7200.7 - bottom U bracket	41-44	46
80GB Cuda IV - top U bracket	38	41
80GB Cuda IV - bay 1	41	41

The jump in temp. probe readings were expected. Not just because of the faster and second Giga 1.33GHz CPUs, but also because the stock heatsink cover with an exhaust fan was removed and not put back, as per GigaDesigns' installation instructions. The heatsink cover in stock configuration probably acts as a heat trap, with the small built-in fan serving to exhaust some of that heat generated by the 733MHz CPU.

Without that cover, some of the (additional) heat generated by the Giga upgrade with two fans can swirl around the case; and the temp probe, close to Giga, was bound to catch it. Some hot air does get pushed out of the vents near the CPU however.

Even with four hard drives in the DA, hard drive temperatures, while higher with the Giga, are well below 60° C max. operating temperature for the Seagate Barracudas.

Additional Cooling

	Digital Audio G4 with GigaDesigns M5D-1213Q and Quicksilver CPU fan housing & fan.

With the Cheetah 15.3K on the horizon, I was curious whether I could lower the temps without using a slot cooler. When I installed the Giga, I was sorry to see the CPU exhaust fan go. Since air was getting forced out the vents near the CPU, I decided to help matters.

While there was the option of cutting out the fan section of the stock plastic heatsink cover, I didn't consider it seriously. I wanted to keep the original parts intact. More importantly, I noticed that the Quicksilvers' rubber CPU fan housing had the same form and size as that section of the DA's plastic heatsink cover. It looked like it would fit. So for US$40 I bought a new QS fan housing and fan (Sunon KDE 1206 PTV1 - 33.5 dbA, 23.5 CFM) and tried it my DA. The 60mm Sunon was part of the deal, and probably not a bad thing since the stock CPU fan was a bit noisy after years of use.

The QS housing fits perfectly where the DA's CPU fan used to be without any case modifications, although different mounting holes and machine screws are used. I reversed the QS fan so it exhausts -- in a QS it's an intake fan. I stuck a piece of tape over the hole on top of the housing to help direct the air out of the case, much like the DA's original heatsink cover which didn't have a hole on the beveled section. The DA's stock CPU fan plugged into the 733MHz CPU daughtercard. So to power the fan I made my own leads that run around the motherboard, just like the Giga M-series 12V leads. One end was tailed with a 2-pin fan connector (male) so the fan's connector plugs right in, which can be seen below. The other end was tailed with a standard 4-pin Molex PATA HD connector. Using the 2-pin fan connectors, rather than splicing, makes it easy to remove the fan for cleaning or replacment.

Left: CPU vents and mounting	Right: Fan modifications and power

I wired the QS CPU fan for 12V, and it dropped both the case (temp probe) and HD temps. But at 12V the fan was little too much like a leaf-blower for my tastes. So I lowered the voltage to 7V (using the standard wiring trick explained here), and it still kept things cooler than no CPU exhaust fan. Here is the complete set of results for easy comparison:

Temperatures (°C)	733MHz DA CPU fan	2 x 1.33GHz No QS CPU fan	2 x 1.33GHz QS CPU fan @ 12V	2 x 1.33GHz QS CPU fan @ 7V
Ambient	22-23	22	22	23-24
Temp. probe	31	40.6 - 41.4	35.6 - 36.4	37 - 37.5
120GB 7200.7 - bottom U bracket	41 - 44	46	42	44 - 45
80GB Cuda IV - top U bracket	38	41	38	39
80GB Cuda IV - bay 1	41	41	38	39

At 7V I can't hear the CPU fan over the case and PSU fans; temp. probe/case temps are still lower; and HD temps are still close to stock temperatures, even with an ambient temperature a tick higher. So I've left the fan at 7V since it hits the right balance between noise and cooling -- and no slot lost to a slot cooler.


Next: Part III: System Benchmarks

I. Intro & Installation | II. Temps and Cooling | III. System Tests | IV. Graphics Tests | V. Apps Tests

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