Why Sandy Bridge Matters for Notebooks

To say that we were caught off guard by Intel’s announcement last Monday of a flaw in their 6-series chipsets would be an understatement. Bad as that was, it’s the OEMs and system builders that are really feeling the pain—not to mention all the money Intel is losing on this “not a recall”. We’ve seen plenty of manufacturer statements about what they’re doing to address the problem, and we’ve also been talking with our notebook contacts trying to find out how the problem will impact availability.

We’ve also had more than a few delayed/canceled reviews while we wait for a fix. While we’ve looked at a generic Sandy Bridge notebook and a few motherboards, there was still plenty more we wanted to discuss. One such notebook came with a “low-end” i7-2630QM processor and a GTX 460M GPU, packed into a 15.6” chassis and sporting a 1080p LCD and RAID 0 hard drives. The manufacturer asked us to hold off on the full review, and we’ve returned the notebook, but not before we ran it through our suite of mobile benchmarks. Rather than complete a full review of a notebook that may or may not be available, we thought it would be interesting to look at what another SNB notebook would do in comparison to the previous generation parts.

Update: We just got word back, and MSI has given the okay to reveal that the notebook in question is the MSI GT680R; we should hopefully see it return to market in a couple months.

In terms of specs, the notebook in question was very similar to the ASUS G73Jw we reviewed last year. Change the CPU to an i7-2630QM in place of the old i7-740QM, use a different battery and chassis, and you’re set. So exactly what can the 2630QM do relative to the 740QM? We’ve added the complete benchmark results to our Mobile Bench area, so you can quickly see how the two stack up.

If you’re only interested in gaming performance, it’s no surprise that we’re mostly GPU limited with the GTX 460M. The majority of titles are 2-8% faster with the Sandy Bridge setup, but we’re also dealing with updated drivers so the performance increase may come at least in part from NVIDIA. That said, there are a couple of outliers: 900p STALKER: Call of Pripyat shows a massive performance increase, as does 900p StarCraft II. How much of that comes from drivers and how much from the CPU? Since we don’t have the G73Jw around to retest, it’s impossible to say for certain, but we can look at the CPU tests to see how much faster Sandy Bridge can be compared to Clarksfield.

PCMark as usual is heavily influenced by the storage subsystem, so RAID 0 versus a single HDD gives the unnamed system an inherent advantage. The use of Western Digital’s Scorpio Black drives versus a Seagate Momentus 7200.4 is another benefit in the storage area—WD has generally come out on the top of the HDD heap with their Black series (though SSD’s are still much faster). Ignoring PCMark, though, we still see a large advantage for the 2630QM. Single-threaded performance is 21% faster in Cinebench 10/11.5, which in our experience correlates well with general Windows use. In the heavily multithreaded tests, the gap increases to 47-58% in Cinebench and x264 encoding.

It’s not just about performance either. While the 2630QM notebook has a larger 87Wh battery, factoring that into the equation we still see relative battery life improved over the G73Jw by 17% at idle, 40% in H.264 playback, and 42% in Internet surfing. Looking at the comparison with 2820QM with HD Graphics 3000, the GTX 460M still clearly takes a toll on battery life (less than half the relative battery life), but it’s good to see more than three hours of mobility from a gaming laptop.

We’re curious to see if anyone is willing to do Optimus with a 460M (or higher) GPU and a quad-core SNB processor, as that will only serve to further increase battery life. Of course, we still see occasional glitches with Optimus that might make OEMs slow to use it on high-end gaming systems. For instance, Empire: Total War won’t let you select higher than “Medium” detail defaults (because it queries the IGP capabilities rather than the dGPU). Left 4 Dead 2 also had some oddities with the latest driver update—you can’t max out the graphics settings and have it run properly with a GT 420M Optimus in our experience; you have to drop the “Paged Pool Memory Available” setting to Low instead of High/Medium or it will exit to the desktop. The result is lower performance/compatibility relative to discrete GPUs, but I’d be willing to deal with the occasional bug for dramatically improved battery life.

So far the Sandy Bridge discussion has been quad-core SNB vs. quad-core Clarksfield, and that’s the other looming question: just how good will the dual-core SNB chips be? We expect better than Arrandale performance and better than Arrandale and Core 2 Duo battery life, but we haven’t been able to test any dual-core SNB systems yet. Unfortunately, the chipset bug/recall/whatever-you-want-to-call-it means we won’t be able to categorize dual-core SNB performance for at least another month, probably two. It appears the revised chipset allocation is going to go first towards big OEMs (i.e. Dell, HP, etc.), and it would seem Intel is focusing first on getting the mobile chipset fixed over the desktop chipset. Several manufacturers have indicated they expect laptops with the revised chipset to hit the market in the late-March to early-April time frame.

A Farewell to the Dell XPS 14
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  • Stuka87 - Monday, February 7, 2011 - link

    I keep having to wait longer and longer to get a notebook. But I don't want to buy a previous generation machine :/

    Thanks for the update though :)
    Reply
  • ajp_anton - Monday, February 7, 2011 - link

    "and multithreaded tasks like video encoding and 3D rendering generally need more floating-point performance."

    The developers of x264 say that it (don't know about other encoders) uses pretty much only integer math.
    Reply
  • JarredWalton - Monday, February 7, 2011 - link

    See above: do they do integer math using MMX/SSE, or do they do it with regular integer instructions? At least one post I read from an x264 developer (http://x264dev.multimedia.cx/archives/51) makes me think they're using SSE/MMX extensions, which would use the FP registers if I'm not mistaken. "Emulating these float ops with complex series of integer ops is far too slow to be worthwhile, so unfortunately we cannot fully abide by Intel’s advisories." If anyone can confirm how much pure integer vs. MMX/SSE video encoding uses, I'm all ears.

    x264 is only one implementation, so we also have H.264 in general, WME, DivX, etc. we could discuss. Given how the GPU people are leveraging their DX10/11 cores to accelerate encoding/transcoding, and GPUs are considered "FP monsters" (even if they're working on INTs in FP registers), again it makes me think the dual-integer core design of Bulldozer might not be ideal for video encoding. We'll find out for sure in the next few months when the CPUs hit retails, of course, so all I can do right now is speculate.
    Reply
  • ajp_anton - Tuesday, February 8, 2011 - link

    I don't know enough to give a good answer, but I think it has something to do with the fact that you can do multiple 8-bit ints instead of one single 32-bit that gives x264 so much speed. No (CPU) "FP monster" can make up for this advantage, as they can only do 32-bit floats.
    You could convert x264 to use floats instead of ints everywhere and get the same result, but you would lose a lot of speed.
    Or something... =)
    Reply
  • LostPassword - Monday, February 7, 2011 - link

    Sad to hear about HP LCD. Main reason I considered an envy Reply
  • jonup - Monday, February 7, 2011 - link

    Why are all Sandy Bridge laptops recalled if the two SATA3 ports are not affected by the recall? Most notebooks utilize only one HDD/SSD and an optical drive. Were most laptops built around the SATA2 controller, or is it that the SATA3 controller is affected by the recall but not as frequently as the SATA2 one? Is the holdup mandated by Intel regardless of which controller is used? Can you elaborate on this? It will be greatly appreciated.
    Thank you!
    Reply
  • JarredWalton - Monday, February 7, 2011 - link

    eSATA, and I think a lot of laptops may have simply used the SATA 3.0Gbps ports even though 6.0Gbps ports were available. Reply
  • jonup - Monday, February 7, 2011 - link

    Thanks! Reply
  • jonup - Tuesday, February 8, 2011 - link

    I just read that Intel allowed partners to ship devices if the partners guarantee that they are not using the faulty controller. So we should start seeing some Sandy Bridge lappy's soon.

    Disclaimer: Intel's announcement came after your response yesterday.
    Reply
  • JarredWalton - Tuesday, February 8, 2011 - link

    Yeah, I would think some of the budget stuff (i.e. Acer where they only have one HDD, one DVD/BRD, and no eSATA) could go out. Hope to see it soon! Reply

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