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.
Facebook
Twitter
RSS
283 Comments
View All Comments
GeorgeH - Monday, January 3, 2011 - link
With the unlocked multipliers, the only substantive difference between the 2500K and the 2600K is hyperthreading. Looking at the benchmarks here, it appears that at equivalent clockspeeds the 2600K might actually perform worse on average than the 2500K, especially if gaming is a high priority.A short article running both the 2500K and the 2600K at equal speeds (say "stock" @3.4GHz and overclocked @4.4GHz) might be very interesting, especially as a possible point of comparison for AMD's SMT approach with Bulldozer.
Right now it looks like if you're not careful you could end up paying ~$100 more for a 2600K instead of a 2500K and end up with worse performance.
Gothmoth - Monday, January 3, 2011 - link
and what benchmarks you are speaking about?as anand wrote HT has no negative influence on performance.
GeorgeH - Monday, January 3, 2011 - link
The 2500K is faster in Crysis, Dragon Age, World of Warcraft and Starcraft II, despite being clocked slower than a 2600K. If it weren't for that clockspeed deficiency, it looks like it also might be faster in Left 4 Dead, Far Cry 2, and Dawn of War II. Just about the only game that looks like a "win" for HT is Civ5 and Fallout 3.The 2500K also wins the x264 HD 3.03 1st Pass benchmark, and comes pretty close to the 2600K in a few others, again despite a clockspeed deficiency.
Intel's new "no overclocking unless you get a K" policy looks like it might be a double-edged sword. Ignoring the IGP stuff, the only difference between a 2500K and a 2600K is HT; if you're spending extra for a K you're going to be overclocking, making the 2500K's base clockspeed deficiency irrelevant. That means HT's deficiencies won't be able to hide behind lower clockspeeds and locked multipliers (as with the i5-7xx and i7-8xx.)
In the past HT was a no-brainer; it might have hurt performance in some cases but it also came with higher clocks that compensated for HT's shortcomings. Now that Intel has cut enthusiasts down to two choices, HT isn't as clear cut, especially if those enthusiasts are gamers - and most of them are.
Shorel - Monday, January 3, 2011 - link
I don't ever watch soap operas (why somebody can enjoy such crap is beyond me) but I game a lot. All my free time is spent gaming.High frame rate reminds me of good video cards (or games that are not cutting edge) and the so called film 24p reminds me of the Michael Bay movies where stuff happens fast but you can't see anything, like in transformers.
Please don't assume that your readers know or enjoy soap operas. Standard TV is for old people and movies look amazing at 120hz when almost all you do is gaming.
mmcc575 - Monday, January 3, 2011 - link
Just want to say thanks for such a great opening article on desktop SNB. The VS2008 benchmark was also a welcome addition!SNB launch and CES together must mean a very busy time for you, but it would be great to get some clarification/more in depth articles on a couple of areas.
1. To clarify, if the LGA-2011 CPUs won't have an on-chip GPU, does this mean they will forego arguably the best feature in Quick Sync?
2. Would be great to have some more info on the Overclocking of both the CPU and GPU, such as the process, how far you got on stock voltage, the effect on Quick Sync and some OC'd CPU benchmarks.
3. A look at the PQ of the on-chip GPU when decoding video compared to discrete low-end rivals from nVidia and AMD, as it is likely that the main market for this will be those wanting to decode video as opposed to play games. If you're feeling generous, maybe a run through the HQV benchmark? :P
Thanks for reading, and congrats again for having the best launch-day content on the web.
ajp_anton - Monday, January 3, 2011 - link
In the Quantum of Solace comparison, x86 and Radeon screens are the same.I dug up a ~15Mbit 1080p clip with some action and transcoded it to 4Mbit 720p using x264. So entirely software-based. My i7 920 does 140fps, which isn't too far away from Quick Sync. I'd love to see some quality comparisons between x264 on fastest settings and QS.
ajp_anton - Monday, January 3, 2011 - link
Also, in the Dark Knight comparison, it looks like the Radeon used the wrong levels (so not the encoder's fault). You should recheck the settings used both in the encoder and when you took the screenshot.testmeplz - Monday, January 3, 2011 - link
Thanks for the great reveiw! I believe the colors in the legend of the graphs on the Graphics overclocking page are mixed up.THanks,
Chris
politbureau - Monday, January 3, 2011 - link
Very concise. Cheers.One thing I miss is clock-for-clock benchmarks to highlight the effect of architectural changes. Though not perhaps within the scope of this review, it would nonetheless be interesting to see how SNB fairs against Bloomfield and Lynnfield at similar clock speeds.
Cheerio
René André Poeltl - Monday, January 3, 2011 - link
Good performance for a bargain - that was amd's terrain.Now sandy bridge for ~200 $ targets on amd's clientel. A Core i5-2500K for $216 - that's a bargain. (included is even a 40$ value gpu) And the overclocking ability!
If I understood it correctly: Intel Core i7 2600K @ 4.4GHz 111W under load is quite efficient. At 3.4 ghz 86 W and a ~30% more 4.4 ghz = ~30% more performance ... that would mean it scales ~ 1:1 power consumption/performance.
Many people need more performance per core, but not more cores. At 111 W under load this would be the product they wanted. e.g. People who make music with pc's, not playing mp3's but mixing, producing music.
But for more cores the x6 Thuban is the better choice on a budget. For e.g. building a server on a budget intel has no product to rival it. Or developers - they may also want as many cores as they can get for their apps to test multithreading performance.
And Amd's also scores with their more conservative approach when it comes to upgrading e.g. motherboards. People don't like to buy a new motherboard every time they upgrade the cpu.