What Nehalem is really about
by Johan De Gelas on August 19, 2008 12:00 AM EST- Posted in
- IT Computing general
IDF has started and the first benchmarks of Nehalem are going to start popping up. It is without a doubt an impressive architecture with a much better platform to run on, but this CPU is not about giving you better frames per second in your favorite game than the Penryn family. Let me make that more clear: even when the GPU is not the bottleneck, it is likely that most games will not be significantly faster than on Penryn. We, the people behind it.anandtech.com will probably have the most fun with it, more than your favorite review crew at Anandtech.com :-). And no, I have not seen any tests before I type this. Nehalem is about improving HPC, Database, and virtualization performance, and much less about gaming performance. Maybe this will change once games get some heavy physics threads, but not right away.
Why? Most Games are about fast caches and super integer performance. After all, most of the Floating point action is already happening on the GPU. The Core 2 CPUs were a huge step forward in integer performance (not the least because of memory disambiguation) compared to the CPUs of that time (P4 and K8). Nehalem is only a small step forward in integer performance, and the gains due to slightly increased integer performance are mostly negated by the new cache system. In a previous post I told you that most games really like the huge L2 of the Core family. With Nehalem they are getting a 32KB L1 with a 4 cycle latency, next a very small (compared to the older Intel CPUs) 256KB L2 cache with 12 cycle latency, and after that a pretty slow 40 cycle 8MB L3. When running on Penryn, they used to get a 3 cycle L1 and a 14 cycle 6144KB L2. The Penryn L2 is 24 times larger than on Nehalem!
The percentage of L2 caches misses for most games running on a Penryn CPU is extremely low. Now that is going to change. The integrated memory controller of Nehalem will help some, but the fact remains that the L3 is slow and the L2 is small. However, that doesn't mean Intel made a bad choice. Intel made a superbly good choice by improving the performance where Core (Merom/Penryn) was mediocre to good. Penryn was already a magnificent gaming CPU, but it could not beat the AMD competition in HPC benchmarks, and AMD put up a good fight in database performance benchmarks. Now Intel is ready to fix these shortcomings.
Most Database code cannot use the wide architecture of Penryn very well. The number of instructions per cycle can be lower than 0.5 and waiting for the memory is the most probable cause. SMT or Hyper-Threading can do wonders here: while one thread waits for a memory stall, the other thread continues working and vice versa.
Secondly, quad (and eight) socket performance is going to improve a lot as four Nehalems only have to keep four L3 caches in sync, while a similar Tigerton system has to keep eight L2 caches in sync. That is why the cache system is perfect for server performance, but a little less interesting for gaming performance.
The massive bandwidth that the integrated tri-channel memory controller delivers should also do wonders for HPC code, and the new TLB architecture with EPT will make Nehalem shine compared to its older Core brothers.
No, Nehalem wasn't made for the gaming enthusiasts. Rather, it was made to please the IT and HPC people. So we say bring it to it.anandtech.com; it's just not that interesting for you gamers! ;-)
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mobilecomputing - Monday, February 9, 2009 - link
that much cache is going to make a collosal system. I'll stick with my netbooks for now. http://www.mobile-computing-news.co.uk/features/92...">http://www.mobile-computing-news.co.uk/...rend-in-...Poloasis - Thursday, August 21, 2008 - link
I currently run a E8500 @4.3 W/C and since the Core i7 is not gearing towards gaming, I would not expect intel dropping the Penryn that much unless we all starts running HPC and database @ home.perzy - Thursday, August 21, 2008 - link
This heat wall is really a solid brick wall...I think I will go out and search the bottom of the bargains bins at the shop for height of devolopment: old P4 Prescott 3.8 GHz.
Let's face it, 99% of the software I use are singlethreaded, and like cubic inches, there is no substitute for pure hertz!
del - Friday, October 3, 2008 - link
blah...A 3.0 GHz Core 2 Duo still runs single-threaded apps faster than a 3.8 GHz Pentium 4.
gochichi - Thursday, August 21, 2008 - link
It is ridiculous to wait for desktop parts, particularly for "gamers".ATI just baffled us with a $175.00 very high end graphics card. Memory prices for DDR2 are basically what I would call "free of charge". Seriously, you can get 4GB of good RAM for $75.00...
8GB of RAM for a mere $150.00... that is going to take FOREVER to get to that price-point with DDR3... which means that 8GB of RAM will not go obsolete for a long time.
You can ALWAYS wait, but you have to balance out time and money because they are interchangeable. Computers are consumables, and you gotta eat. You can get a Lenovo X300 for $3k or wait ten years and spend $300.00... but what of your ten years of wait, and the lost utility?
I have a stock-clocked Q6600 (picked up a Dell refurbished desktop for $350.00), 4GB RAM (2 open slots), and Radeon 4850 and I seriously don't see a game worth playing that doesn't run beyond awesome. I hope something much better comes out that makes my system obsolete, that would be so much fun... but in the meantime I'm waiting in comfort and style and yall should too...
Running a single core Pentium is a waste of electricity. What are you using government money or something? You don't have to wait to spend $3k on a desktop and then wait 5 years until it's completely outdated junk... just spend $600 every two years and you'll have a great machine that runs the best software of its time.
In terms of laptops... I AM being a total hypocrite and waiting for LED displays to enter lower price points(one-two weeks now)... but that's because they are truly different than what's out there. I want to be able to see my laptop screen better... so I wait. But massive desktop performance is available right here and right now... waiting while you use outdated and slow junk is just weird.
silversound - Wednesday, August 20, 2008 - link
Should this nahelam be much faster like intel claimed last year? Up to 3 times faster than penryn?Only up to 30% improvement in app and no improvement in games does not deserve a tock...
core2 still way better leap from the sucky P4
CanamAldrin - Wednesday, August 20, 2008 - link
I don't think I'm nitpicking to say that this article is so full of grammatical errors I find it hard to read it fluidly. If English is a second language for the engineer/journalist, please have someone edit his writing before it gets posted. I don't think that is too much to expect from a site of AnandTech's stature.cokbun - Tuesday, August 19, 2008 - link
i'll wait till next year when the mature nehalem comes out, 32 nm sounds good.melgross - Tuesday, August 19, 2008 - link
What I didn't get out of this article is whether gaming performance will be slightly better than Penyrn, about the same as Penyrn, or slightly worse.I don't imagine that there will be a big difference.
ryedizzel - Tuesday, August 19, 2008 - link
lrn2read