ABOUT BENCH FORUMS PODCAST LOGIN REGISTER
PC Components
Smartphones & tablets
Systems
ENTERPRISE & IT
GUIDES

The Nehalem Preview: Intel Does It Again

 by Anand Lal Shimpi on June 5, 2008 12:05 AM EST
108 Comments | Add A Comment
108 Comments

The Socket

With an integrated memory controller, Intel needed a new pinout for Nehalem and the first version with three 64-bit DDR3 memory channels features a 1366-pin LGA interface:


LGA-1366 (left) vs. LGA-775 (right)

The socket is noticeably bigger than LGA-775 as is the mounting area for heatsinks. You can't reuse LGA-775 heatsinks and instead must use a heatsink with mounting holes more spread apart. As far as we can tell, the same push-pin mounting mechanism from LGA-775 is present in Nehalem which is disappointing.

With a larger socket and more pins, the CPU itself is obviously bigger. Here's a shot of our Nehalem compared to a Core 2 Duo E8500:


Nehalem (left) vs. Penryn (right)


Nehalem (left) vs. Penryn (right)

Intel will obviously have dual-channel versions of Nehalem in the future, unfortunately it looks like they will use a smaller socket for mainstream versions of the chip (LGA-1160?). We won't have to deal with socket segmentation just yet and it is always possible that Intel will choose to stand behind a single socket for the majority of the desktop market, reserving LGA-1366 for a Skulltrail-like high end but the strategy is unclear at this point.

Not One Nehalem, but Two The Return of Hyper Threading
PRINT THIS ARTICLE
Comments Locked

108 Comments

View All Comments

  • SiliconDoc - Monday, July 28, 2008 - link

    lol- Buddy you are thinking.

  • magreen - Thursday, June 5, 2008 - link

    Thanks for the amazing preview, Anand!

    I hope you and Gary will get us more Nehalem information quick like bunnies.

  • yottabit - Thursday, June 5, 2008 - link

    Great Article Anand! I'm so excited for this new technology. But that socket and triple channel memory archetecture makes me want to puke in my mouth a little bit. It's very reminiscent to me of the Socket 423/RDRAM era. I have the feeling that they are going to release this setup for a lot of the early adopters and then screw them over by dropping the socket completely, when they decide that Dual Channel DDR3 is fast enough. I can't picture two platforms running side by side, with two entirely different sockets. People whant a Nehalem but need 4 gigs of ram will end up buying 6 Gigs of ram... and DDR3 ain't exactly cheap.

    I wish they had plans to through this into the mainstream faster. I'd love to have one of these, in dual channel variety. I'm still running an old early A64, and I'm holding out for these next gen processors in the next year or two.

    Its awesome to see that nice performance per clock increase, but the triple channel memory is a real slap in the face to me. Its like Intel saying "look, we increase clock for clock performance, but we also decided to use some brute force and raise our power consumption and motherboard complexity for no reason by adding another impractical memory channel". I don't see it as elegant at all. I think they are overcompensating for their lack of memory bandwith in recent times. :-

    Maybe AMD will have a chance to jump in with some nicer Phenom's before Nehalem comes out and actually capture some quad core market?

  • npp - Thursday, June 5, 2008 - link

    I'm tired of all those people who just can live with the fact that the world is spinning and the CPUs that were reviewed here are simply far faster than the Penryn or Phenom you just bought yesterday... Get used to the fact, this is how thing happen today. Nehalem will be probably the most advanced x86 (x64) CPU when launched, and it just happened that Intel developed it - it could have been anybody else, say AMD, or nVidia, or whoever you prefer, no difference to me. Things go ahead, and some vendors simply get the job done first, in the grand scheme of things, it is all the same. All those fanboys I see around sound like some 3 year old children fighting for candy to me, It's amusing to see how AMD or Intel PR locked you up, guys.

    Now a brief question, aimed directly at Anand, I guess: I still can't figure out why memory performance is so low even via an advanced controller such as Nehalem's. As far as I can tell, 3-channel DDR3-1066 should be able to deliver up to 25,5 GB/s of bandwidth, far from the figures we see. How does this happen? And once more: you measured some 46ms latency altogether, how was that obtained? Assuming memory clock of 133Mhz, this should yield something like CAS4 (~30ms) latencies for the memory, am I right?

  • fitten - Thursday, June 5, 2008 - link

    30us

    As far as single/dual/triple channel, it seems that Anand and gang were able to test with all three modes (you'll notice the comment about WinRAR being 10% faster with triple channel compared to single channel on the pre-release motherboard)... so you don't *have* to buy 3 sticks of memory... if you want 4GiB, you should be able to get 1x4 or 2x2 and leave the other slot(s) empty.

  • npp - Thursday, June 5, 2008 - link

    It's all nanoseconds, of course, not milli- or micro, my fault. Never mind, I'm still awaiting some reasonable explanation about the "modest" bandwidth measured. 12GB/s copy is by no means little - I can't say if it's achievable via overclocking today, I'm not into that kind of business - but still I would guess no. Still, it seems little compared to the max. theoretical values.

  • Anand Lal Shimpi - Thursday, June 5, 2008 - link

    I think we may have to wait for a final Nehalem platform before we can make any calls on memory bandwidth figures, but do keep in mind that the amount of usable memory bandwidth will depend largely on how it's being measured. If the algorithm is even slightly compute bound we won't see perfect scaling with theoretical memory bandwidth.

    I'm not sure how Everest measures bandwidth so I can't tell you exactly what numbers we should be seeing there, but it is useful for comparing a relative increase in bandwidth between Penryn and Nehalem.

    Take care,
    Anand

  • npp - Thursday, June 5, 2008 - link

    Thank you very much, very kind of you to bother answering my question! Keep up the good work here at Anandtech.

  • NINaudio - Thursday, June 5, 2008 - link

    I'm not sure hwy everyone is so concerned about DDR3 prices being high. A quick check shows that you can get a 2gig kit of ddr3-1600 for under $150 already. By the time Nehalem is out for mass consumption ddr3 will be even cheaper. I would say that it's pretty realistic to expect to be able to get a 3gig triple channel kit for under $100 and a 6gig triple channel kit for around $175 by the time nehalem is available to us.

  • Anand Lal Shimpi - Thursday, June 5, 2008 - link

    What I'm really interested in is why Intel felt that Nehalem needed a three channel DDR3 memory controller. Will it really be necessary for higher clocked Nehalem (or is it Nehalems)? It'd be great for the versions of Nehalem with integrated graphics but I figured those would mostly be pushed into the mainstream, dual channel SKUs anyways. Looks like we'll have to wait at least a few more months before we can find out for sure.

    -A
Copyright © 2024. All rights reserved.
BENCH
TOPICS
FOLLOW
ABOUT

Log in

Don't have an account? Sign up now