The Sandy Bridge Review: Intel Core i7-2600K, i5-2500K and Core i3-2100 Tested

Intel never quite reached 4GHz with the Pentium 4. Despite being on a dedicated quest for gigahertz the company stopped short and the best we ever got was 3.8GHz. Within a year the clock (no pun intended) was reset and we were all running Core 2 Duos at under 3GHz. With each subsequent generation Intel inched those clock speeds higher, but preferred to gain performance through efficiency rather than frequency.

Today, Intel quietly finishes what it started nearly a decade ago. When running a single threaded application, the Core i7-2600K will power gate three of its four cores and turbo the fourth core as high as 3.8GHz. Even with two cores active, the 32nm chip can run them both up to 3.7GHz. The only thing keeping us from 4GHz is a lack of competition to be honest. Relying on single-click motherboard auto-overclocking alone, the 2600K is easily at 4.4GHz. For those of you who want more, 4.6-4.8GHz is within reason. All on air, without any exotic cooling.

Unlike Lynnfield, Sandy Bridge isn’t just about turbo (although Sandy Bridge’s turbo modes are quite awesome). Architecturally it’s the biggest change we’ve seen since Conroe, although looking at a high level block diagram you wouldn’t be able to tell. Architecture width hasn’t changed, but internally SNB features a complete redesign of the Out of Order execution engine, a more efficient front end (courtesy of the decoded µop cache) and a very high bandwidth ring bus. The L3 cache is also lower and the memory controller is much faster. I’ve gone through the architectural improvements in detail here. The end result is better performance all around. For the same money as you would’ve spent last year, you can expect anywhere from 10-50% more performance in existing applications and games from Sandy Bridge.

I mentioned Lynnfield because the performance mainstream quad-core segment hasn’t seen an update from Intel since its introduction in 2009. Sandy Bridge is here to fix that. The architecture will be available, at least initially, in both dual and quad-core flavors for mobile and desktop (our full look at mobile Sandy Bridge is here. By the end of the year we’ll have a six core version as well for the high-end desktop market, not to mention countless Xeon branded SKUs for servers.

The quad-core desktop Sandy Bridge die clocks in at 995 million transistors. We’ll have to wait for Ivy Bridge to break a billion in the mainstream. Encompassed within that transistor count are 114 million transistors dedicated to what Intel now calls Processor Graphics. Internally it’s referred to as the Gen 6.0 Processor Graphics Controller or GT for short. This is a DX10 graphics core that shares little in common with its predecessor. Like the SNB CPU architecture, the GT core architecture has been revamped and optimized to increase IPC. As we mentioned in our Sandy Bridge Preview article, Intel’s new integrated graphics is enough to make $40-$50 discrete GPUs redundant. For the first time since the i740, Intel is taking 3D graphics performance seriously.

CPU Specification Comparison
CPU	Manufacturing Process	Cores	Transistor Count	Die Size
AMD Thuban 6C	45nm	6	904M	346mm2
AMD Deneb 4C	45nm	4	758M	258mm2
Intel Gulftown 6C	32nm	6	1.17B	240mm2
Intel Nehalem/Bloomfield 4C	45nm	4	731M	263mm2
Intel Sandy Bridge 4C	32nm	4	995M	216mm2
Intel Lynnfield 4C	45nm	4	774M	296mm2
Intel Clarkdale 2C	32nm	2	384M	81mm2
Intel Sandy Bridge 2C (GT1)	32nm	2	504M	131mm2
Intel Sandy Bridge 2C (GT2)	32nm	2	624M	149mm2

It’s not all about hardware either. Game testing and driver validation actually has real money behind it at Intel. We’ll see how this progresses over time, but graphics at Intel today very different than it has ever been.

Despite the heavy spending on an on-die GPU, the focus of Sandy Bridge is still improving CPU performance: each core requires 55 million transistors. A complete quad-core Sandy Bridge die measures 216mm², only 2mm² larger than the old Core 2 Quad 9000 series (but much, much faster).

As a concession to advancements in GPU computing rather than build SNB’s GPU into a general purpose compute monster Intel outfitted the chip with a small amount of fixed function hardware to enable hardware video transcoding. The marketing folks at Intel call this Quick Sync technology. And for the first time I’ll say that the marketing name doesn’t do the technology justice: Quick Sync puts all previous attempts at GPU accelerated video transcoding to shame. It’s that fast.

There’s also the overclocking controversy. Sandy Bridge is all about integration and thus the clock generator has been moved off of the motherboard and on to the chipset, where its frequency is almost completely locked. BCLK overclocking is dead. Thankfully for some of the chips we care about, Intel will offer fully unlocked versions for the enthusiast community. And these are likely the ones you’ll want to buy. Here’s a preview of what’s to come:

The lower end chips are fully locked. We had difficulty recommending most of the Clarkdale lineup and I wouldn’t be surprised if we have that same problem going forward at the very low-end of the SNB family. AMD will be free to compete for marketshare down there just as it is today.

With the CPU comes a new platform as well. In order to maintain its healthy profit margins Intel breaks backwards compatibility (and thus avoids validation) with existing LGA-1156 motherboards, Sandy Bridge requires a new LGA-1155 motherboard equipped with a 6-series chipset. You can re-use your old heatsinks however.

Clarkdale (left) vs. Sandy Bridge (right)

The new chipset brings 6Gbps SATA support (2 ports) but still no native USB 3.0. That’ll be a 2012 thing it seems.

Refer To : http://www.anandtech.com

Best Gaming CPUs For The Money

If you don’t have the time to research the benchmarks, or if you don’t feel confident enough in your ability to pick the right processor for your next gaming machine, fear not. We at Tom’s Hardware have come to your aid with a simple list of the best gaming CPUs offered for the money.

November Updates

With all of the action in the graphics department, November has been a relatively calm month in the CPU world, though we have seen some significant price shifting.

Let's start with Intel's Core i3-540. Now available for about $115 on Newegg, this processor is actually cheaper than the Core i3-530 at the time this column was written. Perhaps Intel is phasing out the 2.93 GHz -530 in favor of its 3.06 GHz -540. In any case, the Core i3-540 inherits the 530's recommendation at $115. Similarly, the 2.66 GHz Core i5-750 favorite has gone up a few dollars, while the 2.8 GHz Core i5-760 has gone down a few, leaving the faster processor with a single $205 recommendation on our list.

AMD's price adjustments are much more notable. The entire Phenom II X6 line seems to have been slashed $20 to $40, with the Phenom II X6 1055T at $179, the 1075T at $200, and the 1090T at $230. While these prices make the X6 line infinitely more interesting from a productivity standpoint, they're only slightly more attractive from a gamer's point of view, since games tend to utilize no more than four CPU cores. The cheaper and higher-clocked quad-core Phenom II X4 processors are a better bet for recreational use, but for a user interested in mixing business with pleasure, the Phenom II X6 prices are a lot more attractive.

On the other side of the coin, the Phenom II X4 is a bit more expensive than it was previously. The $140 Phenom II X4 955 is sadly no more, back up to a more fitting $155 price point. The Phenom II X4 965 and 970 models are now $165 and $185, respectively.

With the end of 2010 so very close, it is now a waiting game for Intel and AMD to release their next-generation products. When the end of the race is so close, the final mile seems to take forever. But it'll be here soon, and we can't wait to see how both companies improve their standing in gaming circles.

Some Notes About Our Recommendations

This list is for gamers who want to get the most for their money. If you don’t play games, then the CPUs on this list may not be suitable for your particular needs.

The criteria to get on this list are strictly price/performance. We acknowledge that there are other factors that come into play, such as platform price or CPU overclockability, but we're not going to complicate things by factoring in motherboard costs. We may add honorable mentions for outstanding products in the future, though. For now, our recommendations are based on stock clock speeds and performance at that price.

Cost and availability change on a daily basis. We can’t offer up-to-the-minute accurate pricing information in the text, but we can list some good chips that you probably won’t regret buying at the price ranges we suggest (and our PriceGrabber-based engine will help track down some of the best prices for you).

The list is based on some of the best US prices from online retailers. In other countries or at retail stores, your mileage will most certainly vary. Of course, these are retail CPU prices. We do not list used or OEM CPUs available at retail.