Modern Day PowerPC Hardware Pt.2 --Memory

The easiest upgrade for the 11,2 is upgrading the memory, which will help ensure the system doesn't slow down as you open more applications and files.  Here are my recommendations for choosing the "right" amount of memory:  

• 4 GB:  Normal use, web browsing, playing multimedia, some media creation, most gaming
• 8 GB:  Heavier gaming, audio editing and creation, full length standard definition video or HD video clip editing and creation, heavy multitasking, compiling code, data analysis
• 16 GB:  Heavy data analysis, full length HD video editing, RAMdisk use

Memory Considerations:  

1. Here is the important thing about the memory in an 11,2:  You have to get precisely the correct type. The 11,2 uses PC2-4200 DDR2 memory.  DDR2 memory is supposed to be backwards compatible, so you will see PC2-6400 memory claiming to be compatible with PC2-4200 memory.  But, the 11,2 memory controller seems to be extremely picky, and when anything other than PC2-4200 memory is installed it will run all memory at PC2-3200 speeds.  I've purchased "PC2-4200 compatible" memory before only to see it reduce the system's memory access speed to PC2-3200.  I purchase all my memory from OWC now, and have never had this problem with memory purchased from them.  
2. The 11,2 has 8 memory slots.  Memory is installed starting with the inner-most two slots and then working your way out to the outer-most slots.  Memory must be installed in pairs.  This means you cannot install a memory module on one side without a matching module on the other side.  For example, you cannot install 6 GB by using 3, 2 GB modules.  Instead, you would have to use two 2 GB modules and two 1 GB modules.  
3. It is best to use fewer, higher capacity modules than more, lower capacity modules.  For example, it is better to use four 2 GB modules to equal 8 GB than to use eight 1 GB modules.  This is due to how the memory controller accesses the memory and is different than how x86 systems work.  
4. Do not use ECC memory unless it is absolutely necessary for your type of work.  ECC memory is Error Correcting Code memory and it detects and corrects when data becomes corrupt in the system memory.  This happens at the bit level and normally is imperceptible to the user.  ECC memory only becomes important if you're doing complex scientific or financial calculations.  However, in addition to a higher cost, using ECC memory will slow memory access by 2-3%.  

Installation:  

Its easy!  

(Video courtesy of OWC)

Modern Day PowerPC Hardware Pt.1

If you want a modern PowerPC Linux system, you unfortunately have less options than if you want an x86 system; but you have a few options.  You could buy something from a-eon.  Their upcoming AmigaOne X5000 has pretty nice specs, but their systems are very costly (a dual-core 1.8 Ghz system is around $2,800).   More affordable systems are available from aCube Systems, but they're also much less impressive ($850 for a single-core 1.1 Ghz system).  Considering these specifications and prices, I'd recommend finding and refurbishing a Power Mac 11,2.  The 11,2 models are the highest-end PowerPC machines Apple ever manufactured, coming in at $3,300.  With a few upgrades the 11,2 models can still serve as competitive systems today.  

• The 11,2 has a relatively modern architecture, supporting PCI Express and SATA
• You can install a modern-day PCI Express graphics card (no, it doesn't have to be flashed or open-firmware)
• These systems can fully utilize the benefits of an SSD
• These systems can accommodate up to 16 GB of memory
• The 11,2 processor clock speeds are still competitive with modern-day offerings; dual 2.0 Ghz, dual 2.3 Ghz, or quad 2.5 Ghz - I highly recommend the quad
• These systems come with USB 2.0 and can accommodate USB 3.0 via a PCI Express expansion card
• The 11,2, like other PPC systems, is fully supported by several Linux distributions

In this series, I will lay out my recommendations for how to refurbish a Power Mac 11,2 into a respectable modern-day system.  I will include hardware recommendations and setup/configuration information.  Of course, it is important to understand there are limitations to this system.  

• Memory:  While the 11,2 can accommodate 16 GB of memory, they use DDR2 memory.  Most current systems use DDR3 memory.  You can still find DDR2 memory at retail.  The use of DDR2 memory is this systems greatest bottleneck, but you can help compensate for this by making sure you are using the correct memory type and optimal configuration (matching pairs, non-ECC) and running the OS from an SSD.  
• PCI Express 1.1:  Most modern systems include PCI Express 3.0.  However, the 11,2 has PCI Express 1.1.  PCI Express 1.1 is almost completely compatible with PCI Express 3.0, it just has a slower data-transfer speed per lane.  This limitation can be a non-issue, and you can overcome any speed issues by making sure you choose cards with more lanes.  I'll go into this more in its own post.  

I should also point out that this entire series can also be applied to the YDL PowerStation, which had basically the same specs as the Power Mac 11,2 quad-core.  However, since the PowerStation is much more difficult to find, I'll call out the 11,2 even though the information applies to both.