Intel's Core i7 870 & i5 750, Lynnfield: Harder, Better, Faster Stronger
by Anand Lal Shimpi on September 8, 2009 12:00 AM EST- Posted in
- CPUs
Multi-GPU SLI/CF Scaling: Lynnfield's Blemish
When running in single-GPU mode, the on-die PCIe controller maintains a full x16 connection to your graphics card:
Hooray.
In multi-GPU mode, the 16 lanes have to be split in two:
To support this the motherboard maker needs to put down ~$3 worth of PCIe switches:
Now SLI and Crossfire can work, although the motherboard maker also needs to pay NVIDIA a few dollars to legally make SLI work.
The question is do you give up any performance when going with Lynnfield's 2 x8 implementation vs. Bloomfield/X58's 2 x16 PCIe configuration? In short, at the high end, yes.
I looked at scaling in two games that scaled the best with multiple GPUs: Crysis Warhead and FarCry 2. I ran all settings at their max, resolution at 2560 x 1600 but with no AA.
I included two multi-GPU configurations. A pair of GeForce GTX 275s from EVGA for NVIDIA:
A coupla GPUs and a few cores can go a long way
And to really stress things, I looked at two Radeon HD 4870 X2s from Sapphire. Note that each card has two GPUs so this is actually a 4-GPU configuration, enough to really stress a PCIe x8 interface.
First, the dual-GPU results from NVIDIA.
| NVIDIA GeForce GTX 275 | Crysis Warhead (ambush) | Crysis Warhead (avalanche) | Crysis Warhead (frost) | FarCry 2 Playback Demo Action |
| Intel Core i7 975 (X58) - 1GPU | 20.8 fps | 23.0 fps | 21.4 fps | 41.0 fps |
| Intel Core i7 870 (P55) 1GPU | 20.8 fps | 22.9 fps | 21.5 fps | 40.5 fps |
| Intel Core i7 975 (X58) - 2GPUs | 38.4 fps | 42.3 fps | 38.0 fps | 73.2 fps |
| Intel Core i7 870 (P55) 2GPUs | 38.0 fps | 41.9 fps | 37.4 fps | 65.9 fps |
The important data is in the next table. What you're looking at here is the % speedup from one to two GPUs on X58 vs. P55. In theory, X58 should have higher percentages because each GPU gets 16 PCIe lanes while Lynnfield only provides 8 per GPU.
| GTX 275 -> GTX 275 SLI Scaling | Crysis Warhead (ambush) | Crysis Warhead (avalanche) | Crysis Warhead (frost) | FarCry 2 Playback Demo Action |
| Intel Core i7 975 (X58) | 84.6% | 83.9% | 77.6% | 78.5% |
| Intel Core i7 870 (P55) | 82.7% | 83.0% | 74.0% | 62.7% |
For the most part, the X58 platform was only a couple of percent better in scaling. That changes with the Far Cry 2 results where X58 manages to get 78% scaling while P55 only delivers 62%. It's clearly not the most common case, but it can happen. If you're going to be building a high-end dual-GPU setup, X58 is probably worth it.
Next, the quad-GPU results from AMD:
| AMD Radeon HD 4870 X2 | Crysis Warhead (ambush) | Crysis Warhead (avalanche) | Crysis Warhead (frost) | FarCry 2 Playback Demo Action |
| Intel Core i7 975 (X58) - 2GPUs | 25.8 fps | 31.3 fps | 27.0 fps | 70.9 fps |
| Intel Core i7 870 (P55) 2GPUs | 24.4 fps | 31.1 fps | 26.6 fps | 71.4 fps |
| Intel Core i7 975 (X58) - 4GPUs | 27.0 fps | 57.4 fps | 47.9 fps | 117.9 fps |
| Intel Core i7 870 (P55) 4GPUs | 24.2 fps | 50.0 fps | 36.5 fps | 116 fps |
Again, what we really care about is the scaling. Note how single GPU performance is identical between Bloomfield/Lynnfield, but multi-GPU performance is noticeably lower on Lynnfield. This isn't going to be good:
| 4870 X2 -> 4870 X2 CF Scaling | Crysis Warhead (ambush) | Crysis Warhead (avalanche) | Crysis Warhead (frost) | FarCry 2 Playback Demo Action |
| Intel Core i7 975 (X58) | 4.7% | 83.4% | 77.4% | 66.3% |
| Intel Core i7 870 (P55) | -1.0% | 60.8% | 37.2% | 62.5% |
Ouch. Maybe Lynnfield is human after all. Almost across the board the quad-GPU results significantly favor X58. It makes sense given how data hungry these GPUs are. Again, the conclusion here is that for a high end multi-GPU setup you'll want to go with X58/Bloomfield.
A Quick Look at GPU Limited Gaming
With all of our CPU reviews we try to strike a balance between CPU and GPU limited game tests in order to show which CPU is truly faster at running game code. In fact all of our CPU tests are designed to figure out which CPUs are best at a number of tasks.
However, the vast majority of games today will be limited by whatever graphics card you have in your system. The performance differences we talked about a earlier will all but disappear in these scenarios. Allow me to present data from Crysis Warhead running at 2560 x 1600 with maximum quality settings:
| NVIDIA GeForce GTX 275 | Crysis Warhead (ambush) | Crysis Warhead (avalanche) | Crysis Warhead (frost) |
| Intel Core i7 975 | 20.8 fps | 23.0 fps | 21.4 fps |
| Intel Core i7 870 | 20.8 fps | 22.9 fps | 21.5 fps |
| AMD Phenom II X4 965 BE | 20.9 fps | 23.0 fps | 21.5 fps |
They're all the same. This shouldn't come as a surprise to anyone, it's always been the case. Any CPU near the high end, when faced with the same GPU bottleneck, will perform the same in game.
Now that doesn't mean you should ignore performance data and buy a slower CPU. You always want to purchase the best performing CPU you can at any given pricepoint. It'll ensure that regardless of the CPU/GPU balance in applications and games that you're always left with the best performance possible.
The Test
| Motherboard: | Intel DP55KG (Intel P55) Intel DX58SO (Intel X58) Intel DX48BT2 (Intel X48) Gigabyte GA-MA790FXT-UD5P (790FX) |
| Chipset: | Intel X48 Intel X58 Intel P55 AMD 790FX |
| Chipset Drivers: | Intel 9.1.1.1015 (Intel) AMD Catalyst 9.8 |
| Hard Disk: | Intel X25-M SSD (80GB) |
| Memory: | Qimonda DDR3-1066 4 x 1GB (7-7-7-20) Corsair DDR3-1333 4 x 1GB (7-7-7-20) Patriot Viper DDR3-1333 2 x 2GB (7-7-7-20) |
| Video Card: | eVGA GeForce GTX 280 |
| Video Drivers: | NVIDIA ForceWare 190.62 (Win764) NVIDIA ForceWare 180.43 (Vista64) NVIDIA ForceWare 178.24 (Vista32) |
| Desktop Resolution: | 1920 x 1200 |
| OS: | Windows Vista Ultimate 32-bit (for SYSMark) Windows Vista Ultimate 64-bit Windows 7 64-bit |
Turbo mode is enabled for the P55 and X58 platforms.
Facebook
Twitter
RSS
343 Comments
View All Comments
goinginstyle - Thursday, September 10, 2009 - link
What is worthless here is your continued ramblings about subjects you have no actual knowledge of right now. Do you own a P55 system? If so, let's see an article from you. Really, you come over spouting off and calling everyone idiots, yet, you we do not see any articles from you at Toms about the subject matter. In fact, we do not see any comments from you anywhere else about P55. Toms, Tech Report, and AT all came to the same conclusion, presented the same type of information (although AT discussed subjects like PCIE), and yet you do not comment on those other websites.Either you are posting here because you think your negative posts will somehow get you attention that your mother never gave you or you are doing to try and look important to the people in charge at Toms. I hope to God that they never allow you to post another piece of garbage on their site. Really, that article was a straight copy and paste from several other articles on the subject along with Wikipedia information. I am surprised you were not sued for plagiarism, maybe you were and that is why you are over here.
So far, all of your ramblings have only proved your total lack of intelligence when it comes to computer components. Once again, when will we see you making comments on Toms about their similar coverage or when can you expect to see your expert PP article on the site?
eternalfantasy - Tuesday, September 8, 2009 - link
Fully agree up to the AMD part. This is the most biased review I've seen published by Anandtech to date. I think a "Buy me now!" link at the end of the article with an Intel sponsored Ad will complete the article perfectly.Stock clock speed CPU review is what highstreet mags for average Joes write about. Excluding what's importent for readers of tech sites, such as:
Clock for clock comparison
Maximum overclock with similer priced CPU/platform
is just blatent attempt at glorifying Intel's mainstream platform to look like more then what it really is. A cheaper mainstream alternative to the X58 that has been avaliable over a year ago.
PassingBy - Tuesday, September 8, 2009 - link
As released, Core i5 and 1156 Core i7 have no IGP market, so presumably people reading this review will have no interest in using an IGP.In any case, we can safely say that your prognostications like 'a brain dead platform for brain dead people' were total bullshit, as many people tried to tell you. Now, many more people can place a Nehalem-based system on their list of possible purchases. Clarkdale will extend Nehalem/Westmere to even lower price points (and yes, then you can start comparing IGPs, if you like).
TA152H - Tuesday, September 8, 2009 - link
You're really confused.Honestly, anyone who knows anything about computers would be pretty stupid to get this platform. It's fine stock, but when you throw in overclock, the i7 920 is the better choice.
But, here's your hypocrisy. This article was main for mainstream people, since there's no overclocking comparisons, really. The IGP is what makes AMD work, and they do sell their processors into this market. Anand was commenting on how AMD had to lower their prices, so within this context the entire market is applicable. You didn't understand the context, did you?
I didn't say the platform was brain-dead, although you seem to be. I said it was brain-damaged. It's a Celeron. If you look at the reviews from better sites, you can see the Bloomfield running at the same speed is faster than the brain-damaged Lynnfield. Anand really tried to obfuscate this, by using bad comparisons or those meant to show the Lynnfield in the best light, instead of just presenting the most useful information. He fooled you, because you're a moron, but not everyone.
I do like this site, or I did, but I'm really getting unnerved by the way they test to show what they want to show, instead of test and then make up their minds. It's really problematic, and it's going to bite them when more people figure this out.
imperialsoren - Tuesday, September 8, 2009 - link
You have a nasty way of conversing.IdolObserver - Wednesday, September 9, 2009 - link
It's not only his nasty way of conversing. He also doesn't have a clue what he is talking about.Zymon - Tuesday, September 8, 2009 - link
I agree in the main part - there are many aspects which seem to have been completely ignored in this, and many other reviews of Lynnfield.It seems strange that you haven't used a level playing field between compared systems: ALL 3 platforms can use DDR3 - you've used X48 for Core 2 chips, but apparently used different RAM than i5. Why on earth have you used an AM2+ board and DDR2 ram for AMD? I guess it's *only* been 9 months since AM3 became available?
As mentioned, a true clock-for-clock comparison would be VERY interesting, using the same RAM, at the same speeds and timings between platforms.
Anand Lal Shimpi - Tuesday, September 8, 2009 - link
Sorry if this wasn't made clear in the review but the Phenom II X4 965 BE used the same test platform as our review of that CPU: an AM3 motherboard with DDR3 memory.I'm out of the office now but I'll update the test tables later this evening to reflect this.
Take care,
Anand
Zymon - Tuesday, September 8, 2009 - link
Cheers for the clarification Anand!- It seemed unusual for one of your articles, hence the comment!
Laters..
snakeoil - Tuesday, September 8, 2009 - link
i want to know if those benchmarks were with the turbo enabled, which would be cheating, because that's overclocking.for every benchmark turbo must be disabled to be fair.
readers are not stupid.