Can I upgrade my older Mac to OS X 10.6 (Snow Leopard)?
The quick and dirty answer is, if your Mac uses an Intel processor then you can upgrade to OS X 10.6 (Snow Leopard). However, there is much more to know before you make a final decision.
Which Mac Do You Have and What Processor Does It Use?
Before you can decide whether you should upgrade to Snow Leopard, you need to know which Mac and processor you have. To find out, you can use Apple’s System Profiler.
- From the Apple Menu, select ‘About This Mac.’
- Click the ‘More Info…’ button.
- In the System Profiler window that opens (the actual window name will be your computer’s name), make sure that the ‘Hardware’ category is selected from the ‘Contents’ list on the left. Only the word ‘Hardware’ should be selected; none of the Hardware sub-categories should be selected.
- Make note of the following:
- Model Name
- Processor Name
- Number of Processors
- Total Number of Cores
- Memory
- Click the ‘Graphics/Displays’ sub-category, located under the ‘Hardware’ category.
- Make note of the following:
- Chipset Model
- VRAM (Total)
Minimum Requirements
Let’s start by determining whether your Mac meets the minimum configuration requirements for OS X 10.6 (Snow Leopard).
Snow Leopard will only run on Macs that have Intel processors. If the ‘Processor Name’ includes the words ‘PowerPC,’ your Mac isn’t capable of running Snow Leopard. In order to run Snow Leopard, the ‘Processor Name’ must include the word ‘Intel.’
You also need at least 1 GB of memory, but since Intel Macs ship with at least 1 GB of memory, if you have an Intel Mac, you don’t need to worry about Snow Leopard’s minimum memory requirements.
64-bit and Grand Central Dispatch
Even if your Mac meets the minimum requirements for running Snow Leopard that doesn’t necessarily mean it will be able to use all of the new features included in Snow Leopard.
The one thing that will make the most difference in how well Snow Leopard performs on your Mac is whether your Mac supports 64-bit architecture and can therefore run the Grand Central Dispatch technology built into Snow Leopard.
64-bit support requires a Mac’s processor(s) to support a 64-bit architecture. Just because the “Processor Name” has the word ‘Intel’ in it does not guarantee the processor supports a 64-bit OS like Snow Leopard.
When Apple first introduced the Intel architecture it used two processor types: Core Solo and Core Duo (Core Duo is not the same as Core 2 Duo). Core Solo and Core Duo both use 32-bit Intel processors. If your ‘Processor Name’ includes the terms ‘Core Solo’ or ‘Core Duo,’ then your Mac will not be able to run in 64-bit mode or take advantage of Grand Central Dispatch.
Any other Intel processor that Apple has used has a full 64-bit architecture. In addition to fully supporting Snow Leopard, the 64-bit processor architecture also provides direct benefits, including speed, larger RAM space, and better security.
Grand Central Dispatch allows Snow Leopard to divvy up processes across multiple processors or processor cores, which will significantly improve the performance of your Mac. Of course, in order to take advantage of this technology, your Mac must have multiple processors or processor cores. You can see how many processors or processor cores your Mac has by clicking the ‘Hardware’ category and looking at the ‘Number of Processors’ and ‘Total Number Of Cores’ on the right side of the window. The more the merrier!
Even if your Mac can’t run in 64-bit mode and use Grand Central Dispatch, Snow Leopard will still provide a modest performance boost because it is optimized for the Intel architecture and has all of the old legacy code stripped out of it.
OpenCL
OpenCL is one of the features built into Snow Leopard. In essence, OpenCL allows applications to take advantage of a graphics chip’s processor, just as if it were another processor core in the Mac. This has the potential to provide vast increases in performance, at least for specialized applications such as CAD, CAM, image manipulation, and multimedia processing. Even routine applications, such as photo editors and image organizers, should be able to increase overall capabilities or performance using OpenCL technologies.
In order for Snow Leopard to use OpenCL your Mac must use a supported graphics chipset. Apple lists the supported graphics chipsets as:
- ATI Radeon 4850
- ATI Radeon 4870
- NVIDIA GeForce 9600M GT
- NVIDIA 8800 GT
- NVIDIA 8800 GTS
- NVIDIA 9400M
- NVIDIA 9600M GT
- NVIDIA GT 120
- NVIDIA GT 130
If the ‘Chipset Model’ value in the ‘Graphics/Displays’ subcategory (under the ‘Hardware’ category) doesn’t match one of the above names, then your Mac currently cannot use the OpenCL technology in Snow Leopard.
Why do I say currently? Because this list is in flux. It represents the graphics chips that Apple has tested, not all the graphics chips that are capable of supporting OpenCL. For instance, both ATI and NVIDIA have older graphics cards and chipsets that are capable of supporting OpenCL, but it will require someone to produce an updated driver for the Mac to make them work.
A special note for Mac Pro users: Early Mac Pros from 2006 shipped with PCI Express v1.1 slots. All OpenGL-compatible graphics cards need PCI Express slots v2.0 or later. So, while you may be able to swap an OpenCL-compatible graphics card into your early Mac Pro and have it run effectively as a standard graphics card, it may have performance issues when it attempts to use OpenCL. For this reason I consider Mac Pros sold before January 2007 unable to run OpenCL
Snow Leopard and Your Mac
To wrap things up, Snow Leopard will only run on Intel-based Macs that have least 1 GB of RAM installed.
Intel-based Macs that have a 64-bit processor architecture will enjoy even better performance with Snow Leopard, because of their ability to run two of Snow Leopard’s core new features: Grand Central Dispatch, and the memory space, speed, and security that 64-bit brings.
If you have a 64-bit Intel Mac with a supported graphics chipset, you’ll enjoy additional performance improvements via the OpenCL technology, which allows a Mac to use the graphics processors as computational processors when they’re not busy doing other things.
