willdenow said:
I don't disagree with many of your points, except to say that the people should understand exactly what they are getting.
I agree, they should. And Apple isn't being misleading about what the i5 750 or i7 860 are. They *are* Nehalem-based processors.
willdenow said:
Lynfields are significantly from different from the original Nehelems, which were intended for the enthusiast segment of the market.
You're mis-using the term Nehalem, as if it is a product itself. Nehalem is nothing more than the underlying microarchitecture, which Intel then readily adapts for various markets. They've been doing this pretty much since the first time where the product lines diverged to provide consumer and server/workstation/etc variants.
The faster interconnect actually does make a difference in some applications that are memory bandwidth starved, even in single core nehelem i7's.
No, what has made the difference in memory bandwidth-intensive applications is the third memory channel. Don't confuse the two. For most performance applications, there's been little shown to support that Lynnfield has suffered because Intel went with a DMI link instead of the QPI link. The QPI links are more critical for multi-socket systems, which is why Intel even *disabled* one of the lanes for Bloomfield - consumer X58-based systems were not going to have multiple sockets, and so the additional QPI link was redundant/not needed.
The issue of the PCIe bus likely won't affect end users for the reasons that you've pointed, mostly because Apple offerings have never been strong on video performance in games.
That's generally been more to Apple's slow support/lack of desire to provide the latest GPU hardware (and yes, I realize it's partly due to GPU manufacturers seeing a limited market for top-end hardware also, so the blame goes to both).
For pretty much every GPU Apple currently offers through its store or via BTO options, the P55 chipset would be more than adequate for SLI/CrossFire if it were available.
And yes, SLI is still not possible, even with Mac Pros which is rather a tragedy because it forces a significant market segment to shun macs.
You realize that one of the biggest criticisms until recently about SLI was its lack of multi-monitor support? How then would a Mac Pro user, many of whom likely utilize dual monitors at least for what they're using it for, benefit from an SLI setup?
SLI and CrossFire combined make up a decent percentage of the gaming market, yes. But the gaming market is largely confined to the Windows PC market, and that's unlikely to change any time soon. Given the other reasons listed above, even if Apple started to support SLI and/or CrossFire, I don't think you'd see it make much of a difference.
My reason for the original post was informational. It is important for people to understand that a 35% boost in performance on a synthetic benchmark simply doesn't reflect actual results on real world software.
That's often the case for *all* new processor releases, however. It has more to do with the fact that benchmarks are designed to stress specific aspects of a hardware's performance under extreme circumstances. The PC enthusiast community often use Prime95 to stress-test an overclocked system's stability for an extended period of time (usually 12-24 hours, sometimes up to 48 hours). Do you really think the standard iMac, Mac Pro or even PC user does anywhere near anything that hardware-intensive? I doubt it.
(It's a shame, but no one has developed the kinds of real world performance benchmarks that are available for the PC.)
Most enthusiasts laugh/scoff at "real world performance benchmarks" though. They're mainly used by hardware review sites to try and provide a visual comparison between products that a user can semi-understand. It's still generally a closed environment, testing specific features, and no where near realistic in terms of what the general user will be doing. Think of all of the applications usually found running in the background on a system, and that alone should give you an idea at just how unrealistic synthetic benchmarks are.
Intel is being disingenious in calling the hyperthreading Lynnfields i7's, given the numerous architectural differences. Every review site that I've read, and I've looked at about a dozen, agrees.
Show me a credible review site that claims it's a dubious distinction by Intel. Most of the reputable hardware review sites that reviewed Lynnfield, never seemed to have an issue with Intel stating that Lynnfield is a Nehalem-based derivative, nor that they used the i7 moniker.
Finally, because this is a brand new iMac design from a number of standpoints, I sincerely believe it is too early to tell if hyperthreading will be more trouble than it's worth. I still remember the mirror door G5 Mac Pros. They were an abomination to the ears and the energy bills. They also acted like space heaters. It seems at least possible to me that the Lynnfield i7 could cause problems.
Why would hyperthreading cause problems? In its original implementation with the Netburst-based P4 architecture, it ended up not being a major issue because there was very little consumer software that made use of multiple cores, and thus the benefits of hyperthreading were generally lost.
Times have changed though, and a lot more software can take advantage of it. Sure, it's still not going to see its full potential *right now*, but each year features more and more multi-core software being released, and so it doesn't hurt for Intel to go ahead and include it.
And I think you lack an understanding of how TDP design works, but the 95W TDP that Lynnfield is rated for, is the *maximum* power consumption you will see it utilize. Thus, even with all four physical cores active and all four hyperthreading logical cores active, you will not see it draw more than 95W TDP.
Along those same lines, an intensive single-threaded application will have TurboMode running at a faster processor speed, and at that time, the processor will still be drawing its maximum 95W TDP. Do you think Apple has not adjusted the 27" iMac's thermal design to account for this?
I can't waste anymore time on this. I've responded three times. Each of you will decide for yourselves in the end. I simply, and humbly, suggest you educate yourself first before pulling the trigger on the top of the line i7. If I'm a jerk for doing, so be it.
You're not a jerk, you're simply uneducated when it comes to Lynnfield and its Nehalem roots.
And there's no way someone can deny that the i5 750 and i6 860 will offer performance increases over the previous Core 2 line, especially since every review of Lynnfield has compared it to the Core 2s and shown that it handily beats them.
Now, if your argument was on the graphical performance of the new 27" iMacs, then you could have made your case, as the mobile 4850 has no business powering intensive graphical applications at that resolution. But that's for another debate.