Core i7 940 Review Shows SMT and Tri-Channel Memory Let-down

[Mr.Guvernment]

Core i7 940 Review Shows SMT and Tri-Channel Memory Let-down


http://www.xtremesystems.org/forums/showthread.php?t=204544

http://www.techpowerup.com/73680/Core_i7_940_Review_Shows_SMT_and_Tri-Channel_Memory_Let-down.html

Core i7 940 Review Shows SMT and Tri-Channel Memory Let-down
As the computer enthusiast community gears up for Nehalem November, with reports suggesting a series of product launches for both Intel's Core i7 processors and compatible motherboards, Industry observer PC Online.cn have already published an in-depth review of the Core i7 940 2.93 GHz processor. The processor is based on the Bloomfield core, and essentially the Nehalem architecture that has been making news for over an year now. PC Online went right to the heart of the matter, evaluating the 192-bit wide (tri-channel) memory interface, and the advantage of HyperThreading on four physical cores. In the tests, the 2.93 GHz Bloomfield chip was pitted against a Core 2 Extreme QX9770 operating at both its reference speed of 3.20 GHz, and underclocked to 2.93 GHz, so a clock to clock comparison could be brought about.







The evaluation found that the performance increments tri-channel offers over dual-channel memory, in real world applications and games, are just about insignificant. Super Pi Mod 1.4 shows only a fractional lead for tri-channel over dual-channel, and the trend continued with Everest Memory Benchmark. On the brighter side, the integrated memory controller does offer improvements over the previous generation setup, with the northbridge handling memory. Even in games such as Call of Duty 4 and Crysis, tri-channel memory did not shine.







As for the other architectural change, simultaneous multi-threading, that makes its comeback on the desktop scene with the Bloomfield processors offering as many as eight available logical processors for the operating system to talk to, it appears to be a mixed bag, in terms of performance. The architecture did provide massive boosts in WinRAR and Cinebench tests Across tests, enabling SMT brought in performance increments of roughly 10~20% with general benchmarks that included Cinebench, WinRAR, TMPGEnc, and Fritz Chess. With 3DMark Vantage, SMT provided a very significant boost to the scores, with about 25% increments. It didn't do the same, to current generation games such as Call of Duty 4, World in Conflict and Company of Heroes. What's more, the games didn't seem to benefit from Bloomfield in the first place. The QX9770 underclocked at 2.93 GHz, outperformed i7 940, both with and without SMT, in some games.






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[DerekT]

I seldom purchase the Intel tick. I will await the data on the second iteration of Nehalem. So far, I am totally unimpressed with the first iteration.

Now is the time where AMD could release a far better processor and take Intel out imo. I don't think they have the architecture, but if they did, it seems as though Intel has stumbled out the gate with Nehalem.

 

[ChinStrap]

*if* i make this move to I7, it's not going to be till tax time with the move coming up i have. it's gonna be really hard to beat my 24/7 setup right now for gaming. the ol' p5e is running very nice and happy right now.

 

[Sgt_Pinto]

basically what we were all expecting yes? These new cores were supposed to not show any real difference in games.

 

[Zurvan]

No benefit for current games, but who knows, SMT will surely benefit multithreaded games

 

[Mr.Guvernment]

yes new game that are multi-threaded will fly on i7 vs c/q2

 

[Shiggity]

Couldn't this be an issue of programs just not being optimized for higher memory bandwidth like programs aren't optimized for more cores?

That's also a shame if Intel can't market tri channel to server buyers better. I'd be interested to see if the memory bandwidth makes more of a difference in virtualization environments.

 

[DragoXT]

High memory bandwidth doesnt do a thing when you dont have alot of on die cache. Right now the c2q have around 2mb of L2 cache per core, granted the cores cant share the data in them, but the core2 arch has shown that the more l2 cache the better the chips perform and as always with intel, high ram OCs do better cause they up the fsb speeds that are bottlenecking their performance, and with large L2's they can suck in more info faster. The new core i7 arch basically has an IMC as the difference between the two. Granted they had to do some sort of messing with the arch to get the IMC in it, but unless they fundamentally changed how the arch works, then the current setup of huge L3 cache and puny 256k L2 per core cache is really going to null out the performance increase of the extra memory bandwidth that intel is usually good for.

Really from where i stand, the core i7 is just a test bed of getting IMC to work and their quickpath stuff working. I would not be surprised at all if the performance gain for real world apps and such doesnt really go up, but goes down till they work the bugs out. The next arch that intel makes that will natively have the IMC and quickpath should be much better than the hodge podge they are throwing together now. Intel has nothing to loose since it has beat AMD pretty bad, but im just glad they are giving AMD a chance to catch up and keep prices competitive, cause without AMD cpu prices would be sky high.

 

[xtkxhom3r]

man i cant wait for some benches with games like Supreme commander,world at war,starcraft 2 ect.... games that will actually make use of extra cores