The Sandy Bridge Pentium Review: G850, G840, G620 & G620T Tested
by Anand Lal Shimpi on August 23, 2011 12:11 AM ESTIn 2006 Intel introduced its tick-tock cadence for microprocessor releases. Every year would see the release of a new family of microprocessors as either a tick or a tock. Ticks would keep architectures relatively unchanged and focus on transitions to smaller manufacturing technologies, while tocks would keep fab process the same and revamp architecture. Sandy Bridge was the most recent tock, and arguably the biggest one since Intel started down this road.
At a high level the Sandy Bridge CPU architecture looked unchanged from prior iterations. Intel still put forth a 4-issue machine with a similar number of execution resources to prior designs. Looking a bit closer revealed that Intel completely redesigned the out-of-order execution engine in Sandy Bridge, while heavily modifying its front end. Sandy Bridge also introduced Intel's high performance ring bus, allowing access to L3 by all of the cores as well as Intel's new on-die GPU.
The Sandy Bridge GPU was particularly surprising. While it pales in comparison to the performance of the GPU in AMD's Llano, it does represent the first substantial effort by Intel in the GPU space. Alongside the integrated GPU was Intel's first hardware video transcoding engine: Quick Sync. In our initial review we found that Quick Sync was the best way to quickly transcode videos, beating out both AMD and NVIDIA GPU based implementations in our tests. Quick Sync adoption has been limited at best, which is unfortunate given how well the feature performed in our tests.
Sandy Bridge wasn't all rosy however. It was the first architecture that Intel shipped with overclocking disabled on certain parts. Any CPU without Turbo Boost enabled is effectively unoverclockable. Intel killed the low end overclocking market with Sandy Bridge.
The overclocking limits were a shame as Sandy Bridge spanned a wide range of price points. The low end Core i3-2100 was listed at $117 while the highest end Core i7-2600K came in at $317. While you can't claim that Sandy Bridge was overpriced at the high end, there's always room for improvement.
Despite abandoning Pentium as a high end brand with the 2006 release of Intel's Core 2 Duo, Intel has kept the label around for use on its value mainstream parts. Last year we saw only two Pentium branded Clarkdale parts: the G6950 and G6960. This year, powered by Sandy Bridge, the Pentium brand is a bit more active.
| 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 Pentium G850 | 2.9GHz | 2 / 2 | 3MB | N/A | N/A | 65W | $86 |
| Intel Pentium G840 | 2.8GHz | 2 / 2 | 3MB | N/A | N/A | 65W | $75 |
| Intel Pentium G620 | 2.6GHz | 2 / 2 | 3MB | N/A | N/A | 65W | $64 |
| Intel Pentium G620T | 2.2GHz | 2 / 2 | 3MB | N/A | N/A | 35W | $70 |
The new Sandy Bridge based Pentiums fall into two lines at present: the G800 and G600. All SNB Pentiums have two cores (HT disabled) with 256KB L2 per core and a 3MB L3 cache. CPU core turbo is disabled across the entire Pentium line. From a performance standpoint, other than missing hyper threading and lower clocks - the Sandy Bridge Pentiums are very similar to Intel's Core i3.
Intel continues to separate the low end from the high end by limiting supported instructions. None of the Pentiums support AES-NI or VT-d. Other than higher clock speeds the 800 series only adds official DDR3-1333 support. The 600 series only officially supports up to DDR3-1066.
All standard Pentiums carry a 65W TDP. The Pentium G620T runs at a meager 2.2GHz and manages a 35W TDP. Regardless of thermal rating, the boxed SNB Pentiums come with an ultra low profile cooler:
These Pentium CPUs work in the same 6-series LGA-1155 motherboards as their Core i3/5/7 counterparts. The same rules apply here as well. If you want video out from the on-die GPU you need either an H-series or a Z-series chipset.
The Pentium GPU
When Intel moved its integrated graphics on-package with Clarkdale it dropped the GMA moniker and started calling it HD Graphics. When it introduced the Sandy Bridge Core i3/5/7, Intel added the 2000 and 3000 suffixes to the HD Graphics brand. With the Sandy Bridge Pentium, Intel has gone back to calling its on-die GPU "HD Graphics".
Despite the name, the Pentium's HD Graphics has nothing in common with Clarkdale's GPU. The GPU is still on-die and it features the same architecture as Intel's HD Graphics 2000 (6 EUs). Performance should be pretty similar as it even shares the same clock speeds as the HD 2000 (850MHz base, 1.1GHz turbo for most models). I ran a quick test to confirm that what Intel is selling as HD Graphics is really no different than the HD Graphics 2000 in 3D performance:
All is well in the world.
Where the vanilla HD Graphics loses is in video features: Quick Sync, InTru 3D (Blu-ray 3D), Intel Insider (DRM support for web streaming of high bitrate HD video) and Clear Video HD (GPU accelerated post processing) are all gone. Thankfully you do still get hardware H.264 video acceleration and fully audio bitstreaming support (including TrueHD/DTS-HD MA).
Missing Quick Sync is a major blow, although as I mentioned earlier I'm very disappointed in the poor support for the feature outside of the initial launch applications. The rest of the features vary in importance. To someone building a basic HTPC, a Sandy Bridge Pentium will do just fine. Personally I never play anything in 3D, never use the Clear Video HD features and never use Intel Insider so I wouldn't notice the difference between a Sandy Bridge Pentium and a Core i5 for video playback.
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dingetje - Tuesday, August 23, 2011 - link
AMD Athlon II X3 455 = 80 bucksIntel G620 = 78 bucks
nuff said
kmmatney - Tuesday, August 23, 2011 - link
You can overclock the AMD processor, though. You can get an Athlon X2 560 black edition, plus a motherboard for $89 at Microcenter (and the last one I bought unlocked to 4 cores). The Phenom II processors can often be had for low prices - they should have included at least one Phenom II in the benchmarks.dingetje - Tuesday, August 23, 2011 - link
lol, with nuff said i meant:they are priced the same and with 3 overclockable cores the AMD is way better deal
ET - Tuesday, August 23, 2011 - link
As you can see, it's apparently not obvious that's the better deal. I agree the AMD is better for enthusiasts. It's worse for people who care about power consumption, and it will be worse for gaming (though perhaps not significantly so if you use an inexpensive GPU).yankeeDDL - Tuesday, August 23, 2011 - link
ET, there's a "Best gaming CPU for the money" article on Tom's hardware: go and see that every CPU up to the Core i5 2400 is AMD.This translates into: if you are into gaming on a budget, there's only one choice.
I agree on your comment on power efficiency: Intel is unrivaled and if your highest priority is power consumption, then the Pentiums are unbeatable.
Of course, the differences measured, are completely irrelevant in a home environment: it may make a difference of $3, $4 in one year, if even. The only place this would really matter to the point that it could be a priority, is for large enterprises. Then again, this is not the entry-level PC for Mr Joe Average.
It is absolutely normal for Intel to use its brand name to charge more, for inferior products. I'm sure AMD would do the same if could. This doesn't change the fact though that if you're after getting the most for your hard earned $$$, if you're after the best price/performance ratio, you cannot possibly choose Intel.
frozentundra123456 - Tuesday, August 23, 2011 - link
I think you had better re-read that chart, yankee, or look at toms today and see the new chart. Intel is well represented all the way to the lowest level:85.00: Athlon II x3 455
100.00: Tie, Phenom II x4 840, Pentium G850
125.00: i3 2100
190.00: i5 2400
220.00: i5 2500K
325.00: i7 2600K
I didnt include an "honorable mention" because the article is "best for the money" but at 120.00 AMD did have an honorable mention for one of the quad core phenoms.
But if you only look at the clear winning categories 125.00 and under, AMD has 2 and intel has 2.
above 125.00 it is all intel. So if you are gaming on a budget, you do have a choice. Intel is tied or ahead except at the very lowest price point.
yankeeDDL - Wednesday, August 24, 2011 - link
Hi Frozentundr,I have read the article very well and what you wrote confirms this exactly: like I said, if you're looking for gaming on a budget, you look at the cheapest CPUs that give you the best "bang" for the bucks.
If you read the comment about the G850: "However, it only offers half of the execution cores as AMD's alternative, and it doesn't even have the Hyper-Threading technology needed to logically address four threads".
Translated: you save on power, but the G850 can be set to choke much easier than a Phenom II X4. I hope you would agree.
You're right about the Core i3: I skipped it when posting my note, but the conclusion totally stands: the lowest priced gaming CPU worth recommending, are AMD.
The Core i3 is an option indeed if you're willing to spend some more on CPU, motherboard, and forsake overclocking as well, but we are already talking about a CPU more than 50% more costly than the Athlon II X3, so calling it "entry level" would be a bit of a stretch.
frozentundra123456 - Wednesday, August 24, 2011 - link
All I was saying is that your original statement was not correct. Intel does have processers listed in the lower end. Now it seems you are changing the conditions of the argument to make your point. You are talking about only the "absolute lowest" price. And as every AMD fan eventually brings up, you can get more cores.Personally, I would even agree with you that I probably would prefer a quad core AMD to a Pentium for sure, maybe even to the i3 2100. But that is not the point. The point is that Intel does have competitive processors in the low end, based on what Tom's said, not on my evaluation.
And I would consider the difference between an 80.00 and 125.00 processor not that significant. I mean, that is the price of one game, or one dinner out for a couple of people.
Bottom line, I dont see how you can call intel processors "overpriced rubbish" based on Toms article. And I am not an intel fan. My first real gaming was done on a single core Athlon XP 2600, but I am just getting tired of AMD continuing to push out CPUs using an outdated architecture.
ypsylon - Tuesday, August 23, 2011 - link
Well I want to build super-duper cheap m-ATX/ITX PC. That slowest of them,G620T, running at 2.2 GHz looks like a good deal. 35W is great when you look at modern CPUs. Perfect for small box which will do trivial task like recording audio tracks or downloading torrents through the night. All of that with min. power drain. And most important thing all of those Pentiums are not as useless as Atoms. What is nice in Atoms [and likes] is only power drain, but performance is highly insufficient even for many trivial jobs. I don't need OC, well to be honest I would love to see VT-d, but heck you can always install XP (it still alive and kicking, and I couldn't care less about M$ propaganda) only or Linux!One thing which I'm not too sure about is the testing procedure. Those CPUs are not targeted at gaming or video editing.
Captmorgan09 - Tuesday, August 23, 2011 - link
I built up a WHS box running a G620T along with 4GB of RAM and 4 1.5TB WD black edition drives in RAID 5. It's not the speediest machine in the block but it runs cool and does the job. The only issue I had was the asus board I bought didn't support the G620T out of the box. Had to take the board to work and use an i5 so that I could boot and update the BIOS.