Intel’s Second-Gen Core CPUs: The Sandy Bridge Review

Meet Intel’s Second-Gen Core CPUs

New Names, Of Course

There are a total of 14 new desktop CPUs launching today (an additional 15 are being made available in the mobile space). The Core i3, i5, and i7 brands persist, roughly denoting entry-level, mainstream, and enthusiast parts. However, the modifiers are changing. Also, Intel is making more rampant use of suffixes at the end of the model names.

Consistent across the new models is the ‘2’ leading each model designator. Of course, this represents Intel’s second-generation Core processors, and is almost-humorously the only component of Intel’s naming scheme that actually means something. The three numbers that follow are arbitrary performance indicators—exactly what you grew accustomed to from the Nehalem-era CPUs. Intel uses clock rate, L3 cache, Hyper-Threading, and Turbo Boost to differentiate one model from another. It’s a safe guess, though, that -2600 is faster than -2500 and so on.

Some of the model numbers end with four digits. Others are succeeded by a K, S, or T. We already know from the Core i7-875K and Core i5-655K that the K denotes an unlocked clock multiplier. Intel is offering two K-series SKUs—the Core i7-2600K and Core i5-2500K—both hit with a premium over the non-K versions. If you’re an enthusiast planning to overclock, it’s worth ponying up the extra cash for the more flexible parts.

S-series parts should be familiar as well. We’ve seen Intel play games with the S designator in the past, dropping performance on its Core i5-750S to hit an 82 W TDP and simultaneously raising its price. The company isn’t giving out prices on its S-class models prior to launch, claiming these are going to be channel-oriented CPUs that you won't be buying online. We do know these “lifestyle” parts feature lower 65 W TDPs, though, and will still hit the same maximum Turbo Boost levels when the thermal headroom exists.

The ‘T’ suffix is new, denoting a handful of low-power 35 and 45 W desktop processors that employ reduced voltages and base clock rates to hit more aggressive thermal profiles. The only model that defies Intel’s establish nomenclature is the Core i5-2390T, which doesn’t feature four cores, like the i5 would suggest, but instead offers two cores with Hyper-Threading. Why this couldn’t have just been a Core i3, I’m not sure.

A New Interface, Too

This one is bound to rile up anyone who recently spent their Christmas cash on a new Lynnfield- or Clarkdale-based platform. Yes, Sandy Bridge employs a new processor interface called LGA 1155. Yes, that’s one-pin off from the existing LGA 1156 interface, breaking the compatibility of a socket that’s just over one year old. In fact, the actual interface is identical; it’s just keyed differently to prevent you from dropping in a Lynnfield- or Clarkdale-based CPU.

Intel says the move to LGA 1155 couldn’t be helped. Sandy Bridge revolves around the idea of integration. Things moved onto the processor die that weren’t there before. And as a result, pins had to be moved around in response. The folks we talked to at Intel insisted that, had it been possible to make Sandy Bridge LGA 1156-compatible, it would have, as the company doesn’t make any money on an interface transition (that’s only partially true—it’s still selling the chipsets that go onto new motherboards).

But before you jump all over Intel for this one, realize that AMD faced the same challenges with its Bulldozer-based Zambezi, expected later this year. The company has gone on record saying it could have made the next-gen processor AM3-compatible, giving up architectural capabilities in the process. The smart move, however, was to simply transition to Socket AM3+, enabling the architecture’s full complement of features.

Bottom line: LGA 1155 breaks compatibility with the existing infrastructure, necessitating a platform upgrade. Unfortunately, the P67/H67 chipsets don’t really give you any features that weren’t already available on high-end P55-based motherboards, so the value proposition takes a substantial hit if you’re already rocking a decent mid-range machine.