Apple released the Macintosh Performa 6400 on August 5, 1996. The 6400 shipped with either a 180 or 200 MHz, PowerPC 603e processor. Our model is a Performa 6400/180. We acquired it in 2008 for $30. The Performa 6400 originally sold for around $2400 US.

The Performa 6400 uses the PowerPC 603e processor, which is soldered to the computer's "Alchemy" main logic board and cooled by a fanless heat sink. As a cost saving measure, the CPU is fixed and thus the Performa 6400 was not originally considered upgradeable. However, later third party upgrades made it possible to upgrade the fixed CPU by use of the Level 2 cache slot. An upgrade installed in the Level 2 cache slot actually overrides the built in CPU.

The Performa 6400 replaced the Performa 6360 and introduced a new tower configuration. The Performa 5400 all-in-one is virtually identical to the 6400, but with a built in monitor. The Performa 6400 uses a very stylized tower case with smooth flowing, rounded curves Apple called "InstaTower". It has a very pleasing look, but it is not the most practical case to use in a tower configuration. To begin with, the thing is difficult to crack open, which defeats the purpose of owning a tower. We challenge anyone to open up a Performa 6400 (without breaking it in the process) in less than five minutes without first studying an instruction manual. The processor board plugs into the case and can be pulled out, so it is clear Apple never intended the Performa 6400 to be like a traditional tower. The ease of getting to the motherboard is small comfort for anyone trying to pry one of these computers open to add or replace a drive.

The Performa 6400/180 shipped with a 1.2 GB IDE hard drive, an AppleCD 600i CD-ROM drive (8x), and a 1.4 MB floppy disk drive. Our 6400/180 has a 1.58 GB hard drive installed. The internal hard drive uses IDE technology, commonly used in DOS-compatible systems of the time, and a standard ATA-2 or IDE interface. The hard drive has a standard 40-pin ATA connector, and a separate 4-pin power connector. The IDE hard drive functions the same as a typical SCSI hard drive. You must replace IDE drives like for like. The IDE drive does not affect SCSI ID selections or SCSI termination schemes. Six external SCSI devices may be daisy-chained through the external SCSI port.

The 6400/180 has a single empty expansion bay located at the top of the computer. The expansion bay includes audio, data, and power connectors for adding a SCSI CD-ROM or other SCSI device. The bay is configured for 5.25-inch devices, but with modification to the carrier, a 3.5-inch SCSI device could be installed. Apple offered an optional 100 MB Zip drive that was installed in this bay. With the optional Zip drive, a different top faceplate with a drive door had to be installed.

The 6400/180 has the following built-in ports, one Apple Desktop Bus (ADB) port, one DB-15 video port, one DB-25 SCSI port, one (RS-232/RS-422) serial printer port, one (RS-232/RS-422) serial modem port (disabled on our 6400), one 3.5 mm sound output port, one 3.5 mm sound input port, and one 3.5 mm headphone jack on front of the computer. Our 6400/180 has the standard 28.8-Kbps modem card installed in the communications slot and an Ethernet card installed in one of the PCI slots. On the front bezel, there is a remote sensor for use with an Apple remote and a toggle button for controlling volume.

The 6400/180 has a variety of slots for expansion. It has two PCI expansion slots (on a riser card), compatible with all PCI 2.0 specification-compliant cards with the addition of Macintosh software drivers. Nubus cards cannot be used in this expansion slot. A communications slot is available for installing a modem or network card. A port actually located off the motherboard at the top of the back of the computer will except an optional TV/FM tuner card. One internal expansion slot is available for video input cards using NTSC, PAL, and SECAM. A 60-pin DAV connector on the video input card supports an optional video card for real-time video display, capture, and overlay. An adapter cable provides backward compatibility with DVA cards designed for the Power Macintosh 5200. The 6400/180 has a Level 2 cache slot. Apple offered an optional 256K Level 2 high performance module. As stated earlier, third party vendors offered CPU upgrades that utilized this slot.

The 6400 shipped with 16 MB standard RAM expandable to 136 MB using JEDEC-standard DIMM devices in two sockets (168-pin fast-paged mode, 70 ns or faster, 2K refresh rate DIMMs). The 6400 has 8 MB of RAM soldered to the motherboard. Our 6400 has 88 MB installed RAM.

The 6400/180 originally shipped with Mac OS 7.5.3 and can support up to Mac OS 9. Our 6400/180 has Mac OS 8.6 installed.

The video capabilities of a run-of-the-mill 6400/180 like ours, one with no special graphic card installed, is unremarkable and somewhat disappointing. The 6400/180 uses 1 MB of system RAM for the video function. The 6400/180 can only produce 16-bit color at 640 x 480 on most compatible monitors and 16-bit color at 800 x 600 on some compatible monitors. 800 x 600 resolution will usually produce 8-bit color unless the monitor has a 60 Hz vertical scan rate. The 6400 will only display 8-bit color at 832 x 624 and 1024 x 728 (that's only 256 colors!). We had to use the ridiculously low resolution of 640 x 480 to get thousands of colors because our Apple Multiple Scan 15AV will display 256 colors at the next highest resolution of 800 x 600 (72 Hz). That is really disappointing and rather pathetic for a tower that originally cost around $2400 in 1996. The 6400 does not have the 2D and 3D built-in hardware graphics acceleration found in its replacement, the Power Macintosh 6500.

The 6400 began life strictly as a "Performa" branded consumer desktop computer, but Apple soon introduced Power Macintosh variants for professionals a few months after its introduction. The Performa 6400 was discontinued on July 12, 1997. It was effectively replaced by the much-improved Power Macintosh 6500, which used the same InstaTower chassis. The Performa 6400 series were the last Macs to use the Performa label. Its successor, the Power Macintosh 6500, was the first personal computer to reach 300 MHz. The InstaTower form factor was retired at the end of the 6500's production run in early 1998.