Intel's Core i5 Analyzed and Tested (150+ Benchmarks)
Intel 2.66GHz Core i5-750

Of the troika of new chips, Intel’s Core i5-750 is likely to be the big hit. With wholesale prices of $200, the average joe or jane can now build a Nehalem-based system for almost as much as a Core 2 or Phenom II box. The key price differentiator is the motherboards. Board’s we’ve seen will likely top out about $225 but many will dip into the $150 range. That makes it significantly different from when Intel’s Core i7-920 launched. Sure it was only $280 (and still a year later) but the boards for the processor all pushed the $300 mark. Even today, it’s hard to get an LGA1366 board for $250.
In performance, the lower clocked Core i5 schools Core 2 Quad Q9550 as well as the Phenom II X4 BE. The Phenom II X4’s massive clock difference actually gets close to the Core i5 in a few benchmarks and surpasses it in two but the cheap Lynnfield is clearly the winner. Against the Core i7, as expected, the Core i5 loses but for many, giving up 10 percent to 25 percent in performance is worth it to save, oh, $300 over the price of the top-end Core i7-870. The performance delta between the i5 and i7 is the greatest in multi-threaded apps. In gaming and apps not optimized for quad cores, they’re a lot closer.
In the final analysis, the Core i5 falls right where Intel’s bewildering branding scheme puts it: faster than Core 2 and Phenom II but slower than i7 and really damned cheap to boot too. Buy this chip is the vast majority of your applications are not optimized for quad-core or more. If, however, your work counts on an increased amount of cores, go the extra mileage for a Core i7 with Hyper-Threading.
Intel 2.8GHz Core i7-860

If you use the Goldilocks formula, this new quad-core, Hyper-Threaded CPU is “just right.” It’s just the right blend of performance to price. At $266 for a 2.83GHz, its most natural enemy is the Core i7-920 in LGA1366. The 920’s primary advantage is increased bandwidth thanks to its tri-channel DDR3 support. But since the vast majority of apps really don’t need that much bandwidth, the 860 is generally faster by five percent thanks to its 5 percent clock advantage. That’s pretty much what we saw in our tests too – about five percent difference in the vast majority of the tests in favor of the 2.8GHz 860. And of course, the 860 also gets a boost from its increased Turbo Boost clocks. A stock 920 will only Turbo as high as 2.93GHz under some loads. The 860 will max out at 3.46GHz under some loads. Why is the Turbo higher on the 860? The 920 was a first generation Nehalem processor and Intel played it very conservatively with the Turbo. With the 860, the company feels more comfortable pushing it higher.
So what should you buy? Both procs are priced the same at $266, but each has its strengths. The 920 has true dual x16 PCI-E 2.0 support thanks to the X58 chipset and discrete PCI-E as well as tri-channel DDR3. Frankly, we think both of those features are pretty minor reasons to choose 920. The main reason to pick a 920 is the upgrade path. In a few months, Intel will introduce a 32nm-based six-coire processor codenamed Gulftown. With Hyper-Threading, you get 12 threads as well as any goodness Intel can squeeze out of the new 32nm process (both the 860 and 920 are 45nm parts). A rig built on 860 will also not see Gulftown and probably will not see a six-core part for quite some time if ever. Again, Intel intends for LGA1156 to be for the mainstream and the 99 percent of mainstream users don’t need 12-threads for their apps nor will they pay out $1,000 for a Gulftown CPU.
That takes us back to the Core i7-860 part. If you save possibly $150 to $200 by building an 860 rig, that can be put toward a faster GPU, a bigger hard driver or a larger monitor. In this economic climate, that’s pretty appealing and really the pick of the litter if you ask us.
Intel 2.93GHz Core i7-870
In this comparison of five CPUs, the 870 was head and shoulders the fastest CPU. Generally, we saw a 5 percent advantage in the 870 – just what you would expect from a 5 percent clock advantage. We did see some interesting results though. The multi-threaded Cinebench 10 actually saw the 870 with a 13 percent higher score. World in Conflict also saw the 870 run away with a 24 percent higher frame rate than the 860. So here’s the real question: Would you pay nearly 100 percent more for that? For most folks, probably not. At $555 for the Core i7-870 and $266 for the Core i7-860, it just makes a hell of a lot sense to give up some of that performance to put towards something else in your machine. And if you really are into being on the ragged edge of performance, it makes a lot more sense to jump in with both feet for an LGA1366 platform and the promise of a six-core upgrade in a few month. So we’re a little ambivalent about the Core i7-870. But make no bones about it, the Core i7-870 is the king of the CPUs that battled today, it’s just not really a “budget” CPU is it?
Intel 2.66GHz Core i7-920

If you haven’t figured it out by now, Intel’s 920 is the chip all three LGA1156 Lynnfield’s were gunning for. A huge hit among the performance budget shoppers, it overclocked well and got you into the Core i7 club without paying through the nose.
With its three new siblings here, the 920 is mostly pushed to the back in performance and pricing competitiveness. The other chips run at higher clocks, automatically Turbo Boost to higher levels and can save you from $150 to $200 in associated building costs. So why bother with the 920? There is still some magic to this old favorite. In this roundup, the 920 was generally in third or second place in the vast majority of the tests. And in some benches, the 920 interestingly bubbled up to the top. Even though its superior tri-channel doesn’t always pay off, it apparently does in Photoshop CS3 where the 920 took top honors and we suspect its superior bandwidth helps keep it in hunt elsewhere too. We had heard early rumors that Intel would axe the 920 once the LGA1156 procs were out but the company has since told us it had no plans to discontinue 920 right now. That’s a good decision too. While LGA1136 is definitely an exclusive club, there’s no reason for Intel to make it even harder to get in. If your only choice to getting an LGA1366 platform was to shell out $500 for a Core i7-950 or $1,000 for a Core i7-975 Extreme Edition, very few people would choose that route.
Of course, the biggest reason to buy 920 is for the path to the Core i9 “Gulftown” CPU that Intel will introduce in a few months. Ideally, you could build a 920 box and use it for a year or so until the Gulftown derivatives drop down enough to become “budget” chips themselves.