Dell Optiplex GX240: Photo Essay of a Quiet PC

Complete|Mobile Systems

Editor's note, June 7, 2002: This review of a Dell system by contributor Michael Hipp appeared originally in February 2002 on his personal website. We felt it worthwhile to update and reprint here for those who are seeking ready-made quiet computer solutions. Michael's first line tells you why.

The Dell OptiPlex GX240 is the quietest commercial system I have ever used. This page is a short photo essay to show some of the features that make it so.

The OptiPlex GX240 is available in a range of configurations, including small Small Form Factor and Small Desktop cases. I chose the more traditional Mini-Tower Chassis.

The specifications of my particular model:

  • Mini-tower case
  • Pentium 4 1.7GHz
  • 256M PC-133 SDRAM
  • 40GB 7200rpm ATA/100 hard drive
  • 16X CD-RW
  • ATI Rage 128 video
  • 10/100 3COM integrated network
  • 3 USB ports, 2 serial, 1 parallel
  • 3.5" floppy drive.

Unlike HP, Dell still does not specify noise ratings in its technical specifications for any of their PCs.

The system came with Windows 2000 SP2 pre-installed. Yes, I know it's not Linux, but it is the best Windows MS ever made. And repeat after me: "Microsoft Windows XP: Just Say No."

Front and Rear Views

Note that the steel chassis is completely enclosed in plastic. Even the drive doors as well as the bottom, top and sides. Some suggest that a covering of plastic (or other sound-absorbing material) is the best starting pont for a truly quiet system. I have heard that Dell cases are made by Palo Alto (?) of CA. Any information about this would be appreciated.

The only exposed metal is at the rear, and even the edges of the back are covered in lips of plastic. Although the Dell uses stamped metal grills over both fans, much of it is small enough to cause little turbulence in the airflow (turbulence = noise).

Note the PSU (power supply unit) fan at the top and the processor/case fan below it. These are the only fans in the unit. Both are very quiet.

The processor fan is a 92mm unit made by NMB (Model 3612KL-04W-B66 Minebea Co., Ltd.).

Getting Inside

The case seems extremely well built and has an innovative swing-apart construction. Note the large hinges on top and bottom. This makes every internal component easy to access (drives, motherboard, PSU, memory slots, expansion slots). I believe this system is probably one of the best in terms of ease of access to internal components.


The drives are all mounted using plastic rails that allow them to slide to the rear. These plastic rails likely contribute somewhat to vibration dampening. They certainly make maintenance of the drives easy.

The hard drive is an IBM DeskStar 60GXP (model IC35L04AVER07-0) of 37.2GB formatted. It is a good performer and seems very quiet. IBM's website says it is 30dba at idle.

P4 Cooler

This is it's best feature, IMHO. The green plastic item is a hood that swings over the P4 chip and heatsink. There is no fan on the heatsink.

The large 92mm fan that mounts on the rear of the case draws air up through this hood and across the heatsink. It acts, apparently, not only as a chip cooler but also as a case fan.

Notice the video card (AGP) in the foreground with no fan and also the northbridge chip between it and the processor. It also has no fan.

A bird's-eye view with the hood tilted up (it is hinged). The stamped sheet-metal P4 heat sink is now visible.

Note in the photos above you can see the power supply. It appears to be a standard ATX unit but I have been told that Dell PSUs are not ATX and if you replace it with an ATX unit, it will install correctly but will fry the motherboard. (Note from a helpful contributor: The following link might be of interest. It claims that Dell stopped using standard mobos and psu's in 1998, and details the wiring Dell now uses. Apparently an adapter is available from under "OEM Replacement").

Another lesson: This system with a P4 1.7GHz processor would, as of this writing, still be considered a high-end unit and it has a normal complement of options inside. But the PSU is only rated at 250W according to the label. I do not know why so many sytems are being built with 400 and 500W power supplies (or more) in simple desktop units. Tremendous overkill, surely.

Another view of the rear of the system:

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