64 bit capabilities core2 duo vs I5/I7
I am looking at buying a new IMac and expect to keep the system at least 5 years. It will be a family system and, hopefully, more resilient to technical change than a system bought for more demanding purposes. I would expect at least 2 and maybe 3 OS upgrades in that period. Info on the net indicates that 64 bit support will continue to evolve with new releases and I would like to feel that core 2 duo technology will not constrain the functionality of new OS releases for that time period.
I raise the point because of discussions in other places on OS development. I also realize that any such constraints might not be of concern to a 'family' computer. But I'm not an impulse buyer and like to feel like I've thought things through before I buy. There is a lot of different technology in the box and my experience with PC's and Mac's is that things change under the cover much faster than people realize, even when there is no perceived technical evolution.
I raise the point because of discussions in other places on OS development. I also realize that any such constraints might not be of concern to a 'family' computer. But I'm not an impulse buyer and like to feel like I've thought things through before I buy. There is a lot of different technology in the box and my experience with PC's and Mac's is that things change under the cover much faster than people realize, even when there is no perceived technical evolution.
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I am looking at buying a new IMac and expect to keep the system at least 5 years. It will be a family system and, hopefully, more resilient to technical change than a system bought for more demanding purposes. I would expect at least 2 and maybe 3 OS upgrades in that period. Info on the net indicates that 64 bit support will continue to evolve with new releases and I would like to feel that core 2 duo technology will not constrain the functionality of new OS releases for that time period.
I raise the point because of discussions in other places on OS development. I also realize that any such constraints might not be of concern to a 'family' computer. But I'm not an impulse buyer and like to feel like I've thought things through before I buy. There is a lot of different technology in the box and my experience with PC's and Mac's is that things change under the cover much faster than people realize, even when there is no perceived technical evolution.
Other than the basic speed increases and obvious advantage of four cores on the i5 and i7 chips, the only major difference that I know of between the i series and the Core 2 series is the ability to hyper-thread (two virtual cores per physical core), and the ability to use Turbo Boost, which temporarily boosts the CPU's performance as long as the heat/voltage maximums are not exceeded. The i5 will use Turbo Boost, and the i7 will use both HT and Turbo Boost. The Core 2 series will do neither, but also, the Core 2 is no longer expected to be the top-performance processor in Intel's lineup. Both, however, are fully 64-bit capable.
The i5/i7 processors are specifically intended for top-performance users. If you aren't a top performance user, you will likely never notice whether you do or don't have those features. The best rule of thumb? If you don't know you need it, you probably don't.
For reference, My sister just recently upgraded from an iMac G5 that was built in 2004. While the G5 is definitely slow compared to her new MacBook, the degree to which it held up over the five (nearly six) years since it was built is definitely impressive.
Apple doesn't really make any machines that can't last a long time. Five to six years, frankly, is par for Apple's course.
Although this will be a family system that doesn't just mean e-mail and web surfing. As 64 bit software, support for GPU's, changes in hardware for multi-processing, graphics support, and maybe GPU support evolve, it could all lead to OS changes that can't be supported by the core 2 duo. There are a lot of amateur, family photographers that like to take advantage of products like Photoshop.
I don't want to start any arguments, philosophical or otherwise. This discussion can stop here. There are more generic discussions on this issue elsewhere in the forums and I was just trying to narrow the scope.
Discussions elsewhere point out the need for both a 64 bit cpu and 64 bit EFI to enable a 64 bit kernel to default load. A kernel that has dropped 32 bit support will also need 64 bit drivers for all the devices in the box, whether from Apple or anyone else. Speculation is that 10.7 may drop support for core solo and core duo processors.
The reason for this speculation is that Core Solo and Core Duo are 32 bit processors, so if 10.7 is fully 64 bit, it won't run on those processors. I can't see anything similar regarding the Core 2 generation. They are fully 64 bit and there's nothing about the Core iX generation that would mean that an OS supports them but not the Core 2.
Karelia, a few significant advances in the Core iX generation (aka Nehalem) that you forgot:
- Integrated memory controller.
- Quick-path interconnect, vastly improving multi-processor support as CPUs can talk directly to each other.
- L3 cache.
- Can handle about 33% more "instruction in flight" than Core 2.
- Better branch prediction.
- Bigger TLB.
The memory stuff means memory bandwidth is increased slightly whilst latency is reduced dramatically. QPI improves multi-processor performance, and the rest serve to give an increased performance-per-clock.If you can justify the extra $$$, go quad core i5/i7. If money is tight, skip it.