The Sandy Bridge Preview
by Anand Lal Shimpi on August 27, 2010 2:38 PM ESTOverclocking Controversy
It wasn’t until the Pentium II that Intel started shipping multiplier locked CPUs. Before then you could set the multiplier on your CPU to anything that was supported by the line, and if you had a good chip and good enough cooling you just overclocked your processor. Intel’s policies changed once remarking, the process of relabeling and reselling a lower spec CPU as a higher one, started to take off.
While multipliers were locked, Intel left FSB overclocking open. That would be an end user or system integrator decision and not something that could be done when selling an individual CPU. However, ever since before the Pentium III Intel had aspirations of shipping fully locked CPUs. The power of the enthusiast community generally kept Intel from exploring such avenues, but we live in different times today.
Two things have changed Intel’s feelings on the topic. First and foremost is the advent of Turbo Boost. So long as Intel doesn’t artificially limit turbo modes, we now have the ability to run CPUs at whatever clock speed they can run at without exceeding thermal or current limits. We saw the first really exciting Turbo with Lynnfield, and Sandy Bridge is going to expand on that as well. On the flip side, Intel has used Turbo as a marketing differentiator between parts so there’s still a need to overclock.
The second major change within Intel is the willingness to directly address the enthusiast community with unlocked K-series SKUs. We saw this recently with the Core i7 875K and Core i5 655K parts that ship fully unlocked for the overclocking community.
The K-series SKUs, these will be more important with Sandy Bridge
With Sandy Bridge, Intel integrated the clock generator, usually present on the motherboard, onto the 6-series chipset die. While BCLK is adjustable on current Core iX processors, with Sandy Bridge it’s mostly locked at 100MHz. There will be some wiggle room as far as I can tell, but it’s not going to be much. Overclocking, as we know it, is dead.
Well, not exactly.
Intel makes three concessions.
First and foremost we have the K-series parts. These will be fully unlocked, supporting multipliers up to 57x. Sandy Bridge should have more attractive K SKUs than what we’ve seen to date. The Core i7 2600 and 2500 will both be available as a K-edition. The former should be priced around $562 and the latter at $205 if we go off of current pricing.
Secondly, some regular Sandy Bridge processors will have partially unlocked multipliers. The idea is that you take your highest turbo multiplier, add a few more bins on top of that, and that’ll be your maximum multiplier. It gives some overclocking headroom, but not limitless. Intel is still working out the details for how far you can go with these partially unlocked parts, but I’ve chimed in with my opinion and hopefully we’ll see something reasonable come from the company. I am hopeful that these partially unlocked parts will have enough multipliers available to make for decent overclocks.
Finally, if you focus on multiplier-only overclocking you lose the ability to increase memory bandwidth as you increase CPU clock speed. The faster your CPU, the more data it needs and thus the faster your memory subsystem needs to be in order to scale well. As a result, on P67 motherboards you’ll be able to adjust your memory ratios to support up to DDR3-2133.
Personally, I’d love nothing more than for everything to ship unlocked. The realities of Intel’s business apparently prevent that, so we’re left with something that could either be a non-issue or just horrible.
If the K-series parts are priced appropriately, which at first indication it seems they will be, then this will be a non-issue for a portion of the enthusiast market. You’ll pay the same amount for your Core i7 2500K as you would for a Core i5 750 and you’ll have the same overclocking potential.
Regardless of how they’re priced, what this is sure to hurt is the ability to buy a low end part like the Core i3 530 and overclock the crap out of it. What Intel decides to do with the available multiplier headroom on parts further down the stack is unknown at this point. If Intel wanted to, it could pick exciting parts at lower price points, give them a few more bins of overclocking headroom and compete in a more targeted way with AMD offerings at similar price points. A benevolent Intel would allow enough headroom as the parts can reliably hit with air cooling.
The potential for this to all go very wrong is there. I’m going to reserve final judgment until I get a better idea for what the Sandy Bridge family is going to look like.
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wut - Sunday, August 29, 2010 - link
Yep. I bet AMD is really wondering about that right now.greenguy - Saturday, August 28, 2010 - link
I bought basically what is an i5-750 based on Anand's review here. Or at least, the Xeon version with hyperthreading (needed ECC RAM).From what I can tell, you get about a 20%-30% improvement over the i5-750, with the same power consumption. That's pretty good. Not only that, you get some competent entry level graphics... which would have good open source drivers. That's somewhat exciting, though I wonder whether it would do multiple monitors. Any idea on that Anand?
Maybe I'll just stick to the cheapest Nvidia discrete cards I can buy, a couple G210s do the trick (to get 4 1920x1200 monitors). Unless Intel can make those G210s redundant, it represents just an incremental bump in performance, as the only thing that is of interest is the increase in CPU. One thing that is nice is that Intel is reputed to have the best open source support for their GPU drivers, which makes things really interesting now they are producing stuff that will compete with the entry level discrete market. It could be really good for Linux/BSD people like myself.
The other thing of interest for me is in the low power, low cost, high numbers of SATA connections space, with ECC. I wonder if Bobcat will have something there, as AMD don't seek to arbitrarily differentiate their markets like Intel does with the ECC RAM.
Also not really sure what the big thing is with the motherboards and same CPU. I tend to keep the same computer as a build. By the time you want to upgrade the CPU, there is invariably other stuff that needs upgrading, e.g. USB3, graphics, SATA, RAM, whatever. So you end up wasting the old parts for not that much benefit. Better to just re-purpose the old machine, and when you have enough money, buy the most performant parts that are still good bang for buck. A good example was the i5-750 about 8 months ago or so. So I don't fault Intel for this.
wut - Sunday, August 29, 2010 - link
Intel's going after the mid range market, where most of the money is. We'll have to wait and see how good AMD's Fusion mid range ends up being. Even if it catches up all the way and achieves performance parity so AMD can make more money by raising prices, Intel would have their newest gen on the market first. Fusion had better be really, really, good...Hrel - Sunday, August 29, 2010 - link
I'd say if that 2500K is 215 or less it'd be a fair buy. I'd still wait for the price to drop below 200 cause that's my absolute cap on a CPU. I am a little annoyed that it doesn't have hyper threading though, from a moral standpoint, I mean, from a raw material standpoint how much does adding hyperthreading cost? nothing! yeah, that's what I thought.Hrel - Sunday, August 29, 2010 - link
Those are some impressive integrated graphics. I've thought this for a while now, but we really don't need a card any lower than the HD5670, and maybe the 5650 in discrete graphics. Prefferably just the 5670 though. If mobo makers start setting aside a single DDR3 slot for the integrated GPU to use and dedicated GPU only memory, like a discrete GPU, so the integrated GPU doesn't have to share system RAM we really won't need low end graphics in laptops at all anymore.mino - Sunday, August 29, 2010 - link
Adequate.5450 is the LOWEST END card from 2008, A facelifted 4350.
And 780G, it FINALLY manages to out-pace, in 2011, is the mainstream part of 2008 too.
In 2011 there will be a 10W Ontario with 5450-class GPU on 40nm bulk ...
On the other hand it seems Intel is thaking the GPU side seriously. Finally.
But they are still where ATI/NV were in 2004 ...
LuckyKnight - Sunday, August 29, 2010 - link
I would have liked to have seen a better comparison when it comes to idle power consumption? How much has it improved since moving to a 45nm->32nm GPU?Also, has Intel addressed the Clarkdale issue of not outputting industry standard 24fps? (23.976 hz)
Miggleness - Sunday, August 29, 2010 - link
I was planning on purchasing an i5-760 in 2 weeks but looks like I'll have to settle for 2nd hand, low end parts instead and wait for the i5-2400's release.Great job Intel. I for one no longer have that much interest in overclocking when I have Turbo boost to compensate for that.
Hope we hear about the official pricing soon.
jfelano - Sunday, August 29, 2010 - link
Intel could have hit one out of the park with this one if it worked on existing s1155 motherboards....unfortunately it doesn't and it screws over everyone who bought into s1156 or s1366.....yet again.siberian 3 - Sunday, August 29, 2010 - link
Hi everyone i've read the preview and i am not so impresed by the performance of SB.The IGPis great but it make sense only for the mobile section of the pc not the desktop!!
From the preview i understand that this is not a real fusion product but an evolution off clarkdale and arandale products.
So i will wait for Llano to see what Amd has to offer!!!