The Sandy Bridge Review: Intel Core i7-2600K, i5-2500K and Core i3-2100 Tested
by Anand Lal Shimpi on January 3, 2011 12:01 AM ESTThe Lineup
I don’t include a lot of super markety slides in these launch reviews, but this one is worthy of a mention:
Sandy Bridge is launching with no less than 29 different SKUs today. That’s 15 for mobile and 14 for desktop. Jarred posted his full review of the mobile Core i7-2820QM, so check that out if you want the mobile perspective on all of this.
By comparison, this time last year Intel announced 11 mobile Arrandale CPUs and 7 desktop parts. A year prior we got Lynnfield with 3 SKUs and Clarksfield with 3 as well. That Sandy Bridge is Intel’s biggest launch ever goes without saying. It’s also the most confusing. While Core i7 exclusively refers to processors with 4 or more cores (on the desktop at least), Core i5 can mean either 2 or 4 cores. Core i3 is reserved exclusively for dual-core parts.
Intel promised that the marketing would all make sense one day. Here we are, two and a half years later, and the Core i-branding is no clearer. At the risk of upsetting all of Intel Global Marketing, perhaps we should return to just labeling these things with their clock speeds and core counts? After all, it’s what Apple does—and that’s a company that still refuses to put more than one button on its mice. Maybe it’s worth a try.
Check Jarred’s article out for the mobile lineup, but on desktop here’s how it breaks down:
Processor | Core Clock | Cores / Threads | L3 Cache | Max Turbo | Max Overclock Multiplier | TDP | Price |
Intel Core i7-2600K | 3.4GHz | 4 / 8 | 8MB | 3.8GHz | 57x | 95W | $317 |
Intel Core i7-2600 | 3.4GHz | 4 / 8 | 8MB | 3.8GHz | 42x | 95W | $294 |
Intel Core i5-2500K | 3.3GHz | 4 / 4 | 6MB | 3.7GHz | 57x | 95W | $216 |
Intel Core i5-2500 | 3.3GHz | 4 / 4 | 6MB | 3.7GHz | 41x | 95W | $205 |
Intel Core i5-2400 | 3.1GHz | 4 / 4 | 6MB | 3.4GHz | 38x | 95W | $184 |
Intel Core i5-2300 | 2.8GHz | 4 / 4 | 6MB | 3.1GHz | 34x | 95W | $177 |
Intel Core i3-2120 | 3.3GHz | 2 / 4 | 3MB | N/A | N/A | 65W | $138 |
Intel Core i3-2100 | 2.93GHz | 2 / 4 | 3MB | N/A | N/A | 65W | $117 |
Intel is referring to these chips as the 2nd generation Core processor family, despite three generations of processors carrying the Core architecture name before it (Conroe, Nehalem, and Westmere). The second generation is encapsulated in the model numbers for these chips. While all previous generation Core processors have three digit model numbers, Sandy Bridge CPUs have four digit models. The first digit in all cases is a 2, indicating that these are “2nd generation” chips and the remaining three are business as usual. I’d expect that Ivy Bridge will swap out the 2 for a 3 next year.
What you will see more of this time around are letter suffixes following the four digit model number. K means what it did last time: a fully multiplier unlocked part (similar to AMD’s Black Edition). The K-series SKUs are even more important this time around as some Sandy Bridge CPUs will ship fully locked, as in they cannot be overclocked at all (more on this later).
Processor | Core Clock | Cores / Threads | L3 Cache | Max Turbo | TDP |
Intel Core i7-2600S | 2.8GHz | 4 / 8 | 8MB | 3.8GHz | 65W |
Intel Core i5-2500S | 2.7GHz | 4 / 4 | 6MB | 3.7GHz | 65W |
Intel Core i5-2500T | 2.3GHz | 4 / 4 | 6MB | 3.3GHz | 45W |
Intel Core i5-2400S | 2.5GHz | 4 / 4 | 6MB | 3.3GHz | 65W |
Intel Core i5-2390T | 2.7GHz | 2 / 4 | 3MB | 3.5GHz | 35W |
Intel Core i5-2100T | 2.5GHz | 2 / 4 | 3MB | N/A | 35W |
There are also T and S series parts for desktop. These are mostly aimed at OEMs building small form factor or power optimized boxes. The S stands for “performance optimized lifestyle” and the T for “power optimized lifestyle”. In actual terms the Ses are lower clocked 65W parts while the Ts are lower clocked 35W or 45W parts. Intel hasn’t disclosed pricing on either of these lines but expect them to carry noticeable premiums over the standard chips. There’s nothing new about this approach; both AMD and Intel have done it for a little while now, it’s just more prevalent in Sandy Bridge than before.
More Differentiation
In the old days Intel would segment chips based on clock speed and cache size. Then Intel added core count and Hyper Threading to the list. Then hardware accelerated virtualization. With Sandy Bridge the matrix grows even bigger thanks to the on-die GPU.
Processor | Intel HD Graphics | Graphics Max Turbo | Quick Sync | VT-x | VT-d | TXT | AES-NI |
Intel Core i7-2600K | 3000 | 1350MHz | Y | Y | N | N | Y |
Intel Core i7-2600 | 2000 | 1350MHz | Y | Y | Y | Y | Y |
Intel Core i5-2500K | 3000 | 1100MHz | Y | Y | N | N | Y |
Intel Core i5-2500 | 2000 | 1100MHz | Y | Y | Y | Y | Y |
Intel Core i5-2400 | 2000 | 1100MHz | Y | Y | Y | Y | Y |
Intel Core i5-2300 | 2000 | 1100MHz | Y | Y | N | N | Y |
Intel Core i3-2120 | 2000 | 1100MHz | Y | N | N | N | N |
Intel Core i3-2100 | 2000 | 1100MHz | Y | N | N | N | Y |
While almost all SNB parts support VT-x (the poor i3s are left out), only three support VT-d. Intel also uses AES-NI as a reason to force users away from the i3 and towards the i5. I’ll get into the difference in GPUs in a moment.
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karlostomy - Thursday, January 6, 2011 - link
what the hell is the point of posting gaming scores at resolutions that no one will be playing at?If i am not mistaken, the grahics cards in the test are:
eVGA GeForce GTX 280 (Vista 64)
ATI Radeon HD 5870 (Windows 7)
MSI GeForce GTX 580 (Windows 7)
So then, with a sandybridge processor, these resolutions are irrelevant.
1080p or above should be standard resolution for modern setup reviews.
Why, Anand, have you posted irrelevant resolutions for the hardware tested?
dananski - Thursday, January 6, 2011 - link
Games are usually limited in fps by the level of graphics, so processor speed doesn't make much of a difference unless you turn the graphics detail right down and use an overkill graphics card. As the point of this page was to review the CPU power, it's more representative to use low resolutions so that the CPU is the limiting factor.If you did this set of charts for gaming at 2560x1600 with full AA & max quality, all the processors would be stuck at about the same rate because the graphics card is the limiting factor.
I expect Civ 5 would be an exception to this because it has really counter-intuitive performance.
omelet - Tuesday, January 11, 2011 - link
For almost any game, the resolution will not affect the stress on the CPU. It is no harder for a CPU to play the game at 2560x1600 than it is to play at 1024x768, so to ensure that the benchmark is CPU-limited, low resolutions are chosen.For instance, the i5 2500k gets ~65fps in the Starcraft test, which is run at 1024x768. The i5 2500k would also be capable of ~65fps at 2560x1600, but your graphics card might not be at that resolution.
Since this is a review for a CPU, not for graphics cards, the lower resolution is used, so we know what the limitation is for just the CPU. If you want to know what resolution you can play at, look at graphics card reviews.
Tom - Sunday, January 30, 2011 - link
Which is why the tests have limited real world value. Skewing the tests to maximize the cpu differences makes new cpus look impressive, but it doesn't show the reality that the new cpu isn't needed in the real world for most games.Oyster - Monday, January 3, 2011 - link
Maybe I missed this in the review, Anand, but can you please confirm that SB and SB-E will require quad-channel memory? Additionally, will it be possible to run dual-channel memory on these new motherboards? I guess I want to save money because I already have 8GB of dual-channel RAM :).Thanks for the great review!
CharonPDX - Monday, January 3, 2011 - link
You can confirm it from the photos of it only using two DIMMs in photo.JumpingJack - Monday, January 3, 2011 - link
This has been discussed in great detail. The i7, i3, and i5 2XXX series is dual channel. The rumor mill is abound with SB-E having quad channel, but I don't recall seen anything official from Intel on this point.8steve8 - Monday, January 3, 2011 - link
the K processors have the much better IGP and a variable multiplier, but to use the improved IGP you need an H67 chipset, which doesn't support changing the multiplier?ViRGE - Monday, January 3, 2011 - link
CPU Multiplier: Yes, H67 cannot change the CPU multiplierGPU Multiplier: No, even H67 can change the GPU multiplier
mczak - Monday, January 3, 2011 - link
I wonder why though? Is this just officially? I can't really see a good technical reason why CPU OC would work with P67 but not H67 - it is just turbo going up some more steps after all. Maybe board manufacturers can find a way around that?Or is this not really linked to the chipset but rather if the IGP is enabled (which after all also is linked to turbo)?