Launched in 2003, the Power Mac G5 was the king of Apple's lineup for about three years, moving from single CPU models to an eventual dual core and quad core lineup. The G5 was discontinued in 2006 to make way for Apple's switch to Intel processors. If you get your hands on one or keep one lying around for video or legacy projects, you'll find that it still packs a solid punch for a ten year old computer. Below are some suggestions on how to maximize your Power Mac to extend its life.
If you need to identify your Mac, its stock configuration, and hardware limits, a great website to use is EveryMac.
Last Updated: 4/23/2016
Power Mac G5s are some of the most hands off Macs ever made. A stock G5, with additional RAM, is a solid computer. There are only a handful of upgrade options. Of those, memory and storage are areas to begin.
The first component to upgrade is your G5's memory. You don't need to max out the RAM. After 8 GB or so, performance improvements are negligible unless you work with large video/data projects. Note that each model has different limits and types of RAM. 4 GB - 8 GB is probably enough. All RAM must be installed in pairs, so keep that in mind as you look for deals. I recommend OWC for RAM, hard drives, and other components that are guaranteed to work with your Mac.
Recommended budget here: $50-60 for 4 GB of RAM
The amazing code wizard responsible for TenFourFox has written an exhaustive, detailed guide to maintenance for your G5. It covers a lot of ground and even spends time talking about liquid cooled machines. You will definitely want to bookmark it and enjoy its insightful information. Always good to have a plan.
Viva PowerPC also has a nice write up about cleaning out and refreshing your G5 for the long haul. Read it here.
A new hard drive can significantly improve the performance of your G5. All Power Mac G5s use SATA, instead of the older IDE bus, and most drives of varying sizes will work fine in your Mac. Yes, newer SATA drives should be backwards compatible. Your G5 can support up to two hard drives internally. Your main decision will be whether to go with a regular platter hard drive in a size of your choice or a solid state drive which is faster and typically more expensive in smaller capacities.
Solid state drives provide even faster boot times and application performance with less heat and power usage. SSDs are more expensive and smaller in size, but even a 128 GB drive would be more than enough for Leopard and a lot of applications. Since Leopard (10.5.8) does not have trim support, you'll want to get a drive with garbage collection built-in, meaning that it recycles unused and used blocks to keep the SSD performing at a high speed.
A final option is a hybrid drive which combines a platter hard drive and a small SSD to serve as a cache. These are somewhat similar to what Apple calls a Fusion Drive. Keep in mind that these should work fine, but the SSD portion is usually very small (around 8 GB). You'll tend to see a boost in performance if you use a core set of apps over and over again within that 8 GB of space. Otherwise, performance will be typical of platter drives.
Recommended budget: For a 60 GB - 128 GB SSD, $60-90
For a regular hard drive or hybrid drive (1 TB or more in size), ~$90
Performance Note: Your G5 has a SATA 1.5 Gb/s interface. Your G5 will not be able to take advantage of the full speed of most newer SATA II or III drives. For SSDs, be wary of refurb options; they may have a limited lifespan. A factory reconditioned platter drive will likely be fine. As usual, pay attention to the reviews of the drives you are considering - some companies have less than stellar track records.
The best SSDs for Power Mac G5s are ones with aggressive garbage collection, aimed to keep the drive running at top speed even without TRIM present. In the past, I've been recommended to go with Sandforce drives, but they are not the only option. Below are a list of recommended drives that have been confirmed to work on a G5. This list will be updated.
Do your best to research SATA I compatibility! - Power Mac G5s do use SATA I, but since it is older technology, some SSDs give unpredictable results. Try to figure out whether or not the drive is compatible with your G5. Read reviews, and search for other Power Mac users and their experience with the drive. If your new SSD is not "seen" by your Mac, try placing it in the upper or lower bays. Remove any other hard drives. Consider booting from another Mac to see if a later version of Leopard can see the drive.
Recommended Setup Note: Most SSDs come with some portion of the drive already partitioned to keep performance nominal. You can add to this partition by leaving a portion of your SSD unformatted. In Disk Utility, for instance, create 2 partitions. One partition is for your OS. The other partition, usually around 10-15% of its total size, is left as unformatted space. For more details on the benefits of this, read this article.
As far as I know, there are no CPU upgrade options for Power Mac G5s. There might be a possibility of slotting in a faster model's motherboard into your existing case. If you find resources about that, send them my way so I can post them here.
My Power Mac G5 did not have the Airport/Bluetooth option installed. That hasn't been a problem, since I rely on a wired internet connection. You can dig around for an Airport/Bluetooth upgrade kit on eBay, but this was a recommended install to be done by an Apple certified technician. I've seen varying reports on how difficult it is, so try at your own risk. In the meanwhile, many small bluetooth dongles for USB work just fine as a stand-in, and there are also USB wireless adapters (usually RALink chipsets) that have solid drivers for Mac. Search for RALink on NewEgg or Google to discover your various options.
Recommended budget: $20-40
A Power Mac G5, depending on its model, has some available video card upgrade options. Keep in mind that a video card will only do so much to speed up your Mac. Even the first Power Mac G5's stock video card fills the basic needs of Leopard - Quartz Extreme and Core Image compatible.
A stock video card is not a bad option, especially if you are sticking to basic tasks of writing, browsing, and so on. If you use applications that really need to offload processing to a video card or try to do some gaming on large screens, a better video card comes into play. Figure out a budget and look for options that might work for you. I moved from the stock 6600 card to a 7800 GT. I'll be honest - I haven't noticed much of a difference, even in games.
This great post on MacRumors highlights the available options of video cards for every Power Mac G5.
A seller named AppleMacanix does sell some nice video cards for a range of prices on eBay.
Recommended budget: ~$100 (unless you have cash to burn)
The good folks at Low End Mac do a great job detailing the various tech specs for lots of Macs, old and new. Find your G5 on this page. Then scroll down to find links to articles and resources for getting the most out of your G5.
Check out this interesting thread on MacRumors which answers tons of question for users of PowerPC Macs. There's no point in me repeating what others suggest.
If you end up with one of the quad core Power Mac G5s, you may discover that you will need to repair the liquid cooling system. There have been reports of some G5s leaking, and the repair process looks like it could be tricky. You might check with local Apple repair shops to see if they might help you with a faulty G5. Here is a link to the repair process.
Thanks to some great readers (Shiunbird, in particular) and fellow G5 fans, I have Youtube links to share.