Upgrading the Power Mac 7500

Originally published 18 July 2000 as a Mac Daniel column for Low End Mac.
Rated "Best of Mac Daniel" (top 15 most-read columns) from six months after its publication until it was pulled from the site.
Revised slightly 31 July 2003.

Q: I have a Power Mac 7500 with 96 MB of memory, 1 GB hard drive, and 120 MHz PPC 604 daughtercard. I want to gradually upgrade it for my daughter to use for educational purposes. What should I upgrade first, particularly to improve CD performance, and where can I get it?

A: You have plenty of memory right now, although you should keep in the back of your mind the old adage, "You can never have too much RAM." The hard drive is a bit on the small side; upgrading this probably won't greatly affect CD-ROM performance, however. The 604 is a plenty fast processor for any educational games at this point.

The two main components that will affect CD-ROM performance most dramatically are (obviously) the CD-ROM drive itself and the video card. The operating system plays a role, too, and if you don't have at least Mac OS 8.1 on that computer, get it. If you can afford it, get 8.5 and upgrade that (with a free download from Apple) to 8.6. You'll thank yourself later.

The 7500 had a decent (for its time) video subsystem, but it's not great. Perhaps the best upgrade right now would be to put an ATI Rage 128-based card in one of your free PCI slots. I recommend the ATI Rage Orion, available from CDW for US$130 plus shipping. It's a reasonably inexpensive card, has 16 MB of video memory (VRAM), and is powered by the wonderful Rage 128 chip, which is the same graphics chip Apple uses in their current high-end desktop machines. The extra cost of the Nexus 128 for twice the VRAM is really only justifiable if your preschooler is going to be playing Quake III or Unreal Tournament, both of which seem a bit inappropriate for her age group. :-)

The CD-ROM is a 4x SCSI drive, unless someone else has already upgraded it. A 4x drive is plenty fast for most CD-based games and such. If you really feel shackled by the slower speed, though, get an 8x or 12x Apple drive,* possibly from eBay (where you'll probably get the best price, even on a new drive). MacResQ, Shreve Systems, or Sun Remarketing might also have the drives available. (They're generally not available at ordinary retail any more, since Apple no longer sells either SCSI-based systems or that slow of a CD-ROM drive.)

* Most third party CD-ROM drives require third party drivers and cannot be used to boot the system. Having a bootable CD-ROM is great if you need to run diagnostics (Norton Utilities, Disk Warrior) or boot from CD so you can replace a damaged system. You can often find Sony 8x and 12x units at MacResQ that are bootable, work with Apple's CD-ROM drivers, and cost less than Apple brand drives.

Once you upgrade the video card, and possibly the CD-ROM, the next upgrade you'll want to look at is a G3 or G4 upgrade. I recommend against trying to upgrade to a faster 604 or 604e simply because they're not a significant increase in performance relative to the money you would put out. You'd be far better off getting a low-end G3 upgrade and spending maybe $50 more. Prices will certainly change by the time you get around to upgrading your processor, because, in my opinion, this is the part of your system that needs the least attention. Right now, you can get a 500 MHz G3 or 400 MHz G4 upgrade for about the same price. My recommendation, knowing that you're not going to be doing heavy number crunching, is to go with the 25% higher clock rate of the G3, because that will give you a noticeable speed boost.

You might need to upgrade the hard drive later, depending on how full it is now and what sort of space those installers for the games and educational software require. The good news is that your 7500 supports a second internal hard drive without too much trouble. You can just order a 50-pin SCSI hard drive and drive rails from any vendor (or eBay), plug it in to the existing cables in the drive bay, format it with Apple's Drive Setup (if necessary), and off you go. I recommend IBM and Seagate mechanisms, but Apple's OEM was Quantum for a while, and those were rock-solid drives. Stay away from Micropolis if you buy used; they had reliability problems.

The very last thing you may want to consider at some point is a memory upgrade. Since this will primarily be a one-application machine for the immediate future, huge amounts of memory are actually unnecessary. As your daughter learns to use the computer more, she may want to run more than just her educational software and games — possibly some email or Web access. I don't know what configuration your 96 MB of RAM is in right now, but if you need more memory later, get a 64 MB chip and put it in an empty slot (or if there isn't an empty slot, remove one of the smaller DIMMs and replace it with the 64 MB chip).

copyright ©2000-2004 by Chris Lawson