How Many CPU Cores Do You Need?

[bboysil]

[citation][nom]ImSpartacus[/nom]This is a terrible article.There is absolutely no contest, out of two processors running the same clocks and everything, the one with more cores will win every time (a few weird quirks aside).I want to see a 3.0GHz E8400 versus that puny 2.4GHz quad. Then overclock them both (maybe use a more modern quad to be fair) as far as you can go stably. When the E8400 tops out at 4.2GHz and the quad at 3.8GHz then bench them again.Then we will see which is the best value.[/citation]

That is not true, the application has to be built to take advantage of multiple cores.

 

[dman157]

Honeslty I think this core race is very stupid. At first it was great and everything, and it gave us a great boost in performance, then Intel came with its quad cores, and now its been a fight for the most cores. You can only get up to so many cores, and I doubt any programmer would like to program for an 8 core beast probably. That's lots of parallel programming. What happened to NASA having a CPU being able to withstand 500C or something like that? This is what companies should be doing. 4 cores should be the max, because anything over that is overkill, and then you just have a waste of power. Both companies (AMD & Intel) should be doing R&D on how to get the frequencies higher and make the processors withstand the heat, or make them cooler. I think that what is also holding back the frequencies are these die shrinks. As the dies get smaller, you have this one big area of heat on a chip, and there is less and less surface area to take away heat, and heat will conduct faster in a smaller area than a bigger area. I think if we had a 90nm 6 GHz CPU it would be a lot cooler than a 35nm 6 GHz CPU. So if you guys at AMD and Intel read this somehow 😛 please consider Moore's Law. I bet he has his hands in his face wondering what we have come to with this core thing. Frequency matters most, forget about cores, because it all comes down to the number of operations you can do per cycle!

 

[Guest]

I think this test is flawed. They should be using a Corei7 and not a dualdual core nature of the core 2 quad. Since its a two dual cores then the third core will have all of the cache available when one is disabled.

 

[Guest]

You should really try this on an AMD or i7 platform. I'm pretty sure that when you see the performance drop from 3 to 4 cores it's because the memory bandwidth is saturated and the cores can't get the information fast enough, I see the same thing in cluster benchmarks.

 

[cleeve]

We are planning a follow-up within the next few months where we will use Phenoms and the i7 to minimize cache impact on the results. Stay tuned!

 

[TechMata]

Thank you very much for this very informative article. I guess I should be worried if whether or not the application supports multi-core. Otherwise, multi-core would be useless.

 

[Tindytim]

[citation][nom]TechMata[/nom]Thank you very much for this very informative article. I guess I should be worried if whether or not the application supports multi-core. Otherwise, multi-core would be useless.[/citation]
Wrong.

If you have a Dual-core, and a game only uses one core, it's performance will be greater then on a single core of the same type, because all the other processes running (the OS, Anti-Virus, etc) can run on the other core, giving a full core to the game.

 

[caribman]

"The other" group of people who read Tomshardware are not interested in gaming but, are interested in how quickly increases in performance will allow them to do their jobs. Non linear video editing, Audio editing/processing, 3D modeling and analysis and server virtualization come to mind. Even just playing around with more than one VM in VMWare or VirtualBox can bring many systems to their knees.

I'd love to see a comparison of a system doing a video transcode operation from within a VM while compiling an application in another VM, running 10 tabs in Firefox and rendering a 3D model all at the same time. I've done two out of the four at the same time on my 1.86Ghz Core 2 Duo and it was a pain. What I want to know is how much an improvement in multitasking performance I could get from one of the Core i7 Quads.

 

[Guest]

I want a laptop with 17 inches screen low power cpu (30w or less)with huge L2 cache (4-6 mb)
Anybody can help?

 

[Guest]

I would now like to see how generations of cpu's have changed such as in efficiency, such as you tested the i7 2.66 quad core, compare that to the quad core 2.66ghz of the 775 skt family Q6800 or what ever the 2.66 quad core was called , also compare them to the athlon x2 and the 2 versions of the phenoms, it would be interesting to see identical clock speed, V's the change in architecture V memory performance

 

[Guest]

Yes, i have to agree with yonef. I was thinking the same thing. Just because Windows only sees 1 core and only schedules accordingly, doesn't mean that other cores are not used.

The cores are not isolated (In this chip and others). If you run a single threaded program it will run on multiple cores. This is done at the underlying hardware level, and cannot be changed by software (say making a change to windows), you would need to find a way to actually disable the core. In this case a thread can be processed between 2 cores. In the case of say a Phenom chip with a native quad core design, a single thread could be processed by all 4 cores.

So actually, in your one core test you could be using up to 2 cores. Also, the two core test could be using 2 or 4 cores depending on which of the two cores are being used by windows. The 3 core test is definitely using all 4 cores. In fact, the only difference between the 3 and 4 core tests is you gave the cpu an extra thread to use. What is actually being tested is more along the lines of hyperthreading vs no hyperthreading.

 

[Guest]

So 18 months later, any additional comments or references?

Great article.

DG12

 

[Guest]

Hey guys, i dont know alot about this, so my question is: Would Call of Duty Black Ops run faster(better) on 1.AMD Phenom II Quad Core N950 (2,1 GHz) or 2.Intel Core i7 2630QM (2 GHz, 6 MB L2). These are from 2 computers im looking to buy, and what about ram, would 8gb make the diffrence from 4gb?

 

[Guest]

Check out the definition of "begs the question". It doesn't at all mean what you think it does.