I have a PowerMac G5 (pre-Intel chip) and am looking to upgrade the RAM (memory). The Apple Tech I spoke with recommended I check out MacMall and specifically mentioned Kingston and Crucial as brands.
Does anyone here have any experience with those brands?
ALso, how can you tell which RAM will work with the Pre-Intel Desktops? Or does that even matter?
Hi! Both are good companies but be sure you buy ram made to be compatible with the mac. Another GREAT place is OWC and you can't go wrong with them. Just remeber the G5 has to have matched pairs. Tom
Crucial and OWC (Macsales.com) both have guides to help you select the correct RAM. I personally have always used OWC's memory which has a lifetime warranty, but many on these boards swear by Crucial as well. They will both sell you RAM that is guaranteed compatible with Macs.
PowerMac G5s support anywhere from 4GB to 16GB, depending on the model.
Thanks guys. I got my ram from MacSales. Someone had mentioned there is a downloadable directions for installing RAM into old G5s here on Apple's website. Can anyone point me in the right direction? Thanks!
DDR2 RAM is not backwards compatible with DDR. Check the system profiler or "About this Mac" to see which RAM you have. The G5 quad has DDR2
The frequency of the RAM, e.g. 533, 667, 800 MHz is the certified or maximum speed and it is backwards compatible, e.g. PC2-8000 is backward-compatible for PC2-4200, PC2-5300, and PC2-6400. PC2-4300 is PC-4200 that has been tested at higher than standard rates.
Old memory modules are often more expensive than newer. There is no reason to buy PC-4200 if you can get PC-6400 for the same price. But you increase your chance to be able to use the same RAM in a newer computer. Higher performance DDR2 RAM is compatible with lower performance and the higher performance module runs at the lower module's frequency. Using lower performing DDR2 memory in a system capable of higher performance results in the bus running at the rate of the lowest performance memory in use.
The biggest question might be whether or not to go for Buffered, Fully Buffered, Registered, Unregistered, or ECC nor non-ECC.
EEC adds correcting minor errors and detecting major errors for better reliability. ECC is a bit more expensive but I prefer the reliability. You can use ECC memory even if your system does not support it, but don't mix ECC and non-ECC modules within the same memory pair or memory bank. Modules with ECC are identified by an additional ECC in their designation., e.g. PC2-4200 ECC
Registered RAM means "buffered", and unregistered means "unbuffered". It provides more reliability and scalability but is somewhat slower than unregistered RAM. If you install registered RAM in a memory bus that does not support it than it will not be used. You can save some money here, but some server platforms use registered RAM. You cannot mix registered and unregistered RAM in your system. Unregistered RAM may be identified by an additional U in the designation. PC2-4200R is registered.
Fully buffered modules, which are designated by F or FB do not have the same notch position as other classes. Fully buffered modules cannot be used with motherboards that are made for registered modules, and the different notch position physically prevents their insertion.
The G5 quad supports ECC. However, my G5 Quad shows PC-4200U, which means memory at 533 Mhz, unregistered and non-ECC. It was probably the cheapest at the time.
I'm going to put PC2-6400U ECC into my G5, which is cheaper than PC2-4300U and I can also put it into an April 2008 iMac, and let you know the results if it does not work.
I put in 800 Mhz Ram (Kingston) and it shows up as PC2-3200 (400 MHz). The previous RAM is still in the computer remains as PC-4200 (533 MHz). Actually when using other tools like "Geekbench" it does not show any speed or type of RAM for the new RAM.
Using Geekbench and Xbench I ran tests with only the new 800 MHz RAM or original 533 MHz RAM in the System, and the results were the same, the 800 MHz was perhaps a little bit faster, although still showing up as 400 MHz.
With both type of RAM in the system I see PC2-4200 and PC2-3200. It means that the system is not reading the speed of the new RAM (PC-6400) properly, but it operates according to the system specs - otherwise the PC2-4200 would also adjust to PC2-3200 if the new memory was indeed running at this slow speed.
I conclude that the PC2-3200 reporting is just a bogus, probably because the system does not understand the info of the RAM, but the hardware initialized and works properly. But I agree it does not look good in System Profiler.
