How Many CPU Cores Do You Need?

[zerapio]

[citation][nom]Tindytim[/nom]Okay, you're kidding.I have a dual monitor setup myself, but I guess I'm one of the few people a bit more mindful of my app useage. Code::Blocks and Bluefish have tabs, so I don't need multiple instances open. I don't understand why you'd need notepad open in addition to an IDE. And what the hell do you need 40 Firefox tabs for? Along with Acrobat?I read documentation while working all the time, but what sort of references do you need to make if you have 40 tabs and acrobat open?Not to mention all of the apps you list take very little processing resources when using them (VB Studio only eats them up when compiling).I'm not trying to make a case against more cores, I can use more cores. However, some of you seem to be spewing bull, and giving a bad name to multitasking.[/citation]
Hey Tindytim, I wish I was kidding. I'm sometimes working on multiple branches of the same project, like when doing regression testing. Other times I can have a solution that I'm using sample open and the code I'm working on. Some coworker might come and ask for help with a compilation error so I go, load up yet another solution and try it out. See? it's easy to have more than one solution open.

Not all the files I change are source code. Some others are scripts. These I normally edit with notepad though I could install Context or Notepad+ at work. I've also at times fire up VS and load the files in there (another VS instance).

With Acrobat I sometimes have multiple technical documents open. They could be specifications, a paper I'm reading, an attachment in an email from some strange country (j/k).

With Firefox I'm just wasteful. Sometimes instead of bookmark something I leave the tab open. Even if FF crashes I recover all my tabs. Other times when I'm researching stuff online I open many tabs while looking for help, code snipets, etc.

None of these apps eat CPU cycles in the background. The ones that do are the AV (big time), the distributed build system and the normal OS stuff. Like you mentioned, during compilation (esp. big projects) you appreciate having as many cores as you want.

 

[Guest]

It would have been useful to include performance of virtual machines running under VMware or MS VPC. It seems to me that VM's represent one of the best uses for a multi-core environment.

 

[Guest]

MP3 conversion in CBR (constant bitrate) mode isn't a parallel task... There's a "bit reservoir" that's carried over from previously encoded frames that were simpler than expected; encoding the subsequent frames requires knowing its size, so the workload can't be split among cores.
Only VBR (variable bitrate) mode is parallelizable, since frames are truly independent from each other and execution units can thus work on different parts of the stream concurrently.
I'm not familiar with the AAC format, but that limitation should apply to it too.

 

[Tindytim]

[citation][nom]zerapio[/nom]Hey Tindytim, I wish I was kidding. I'm sometimes working on multiple branches of the same project, like when doing regression testing. Other times I can have a solution that I'm using sample open and the code I'm working on. Some coworker might come and ask for help with a compilation error so I go, load up yet another solution and try it out.[/citation]
Doesn't change the fact that there is still no need for multiple threads, the mem usage would be the bigger issue.

[citation][nom]zerapio[/nom]Like you mentioned, during compilation (esp. big projects) you appreciate having as many cores as you want.[/citation]
Not always.

You still haven't exhibited why you need more than 2 cores by listing all these applications. Multitasking only matters if these are processor intensive applications. You're just wasting memory.

Here's a couple of my examples:
1. Blender
2. Blender and Inkscape/GIMP
3. Blender, Inkscape, and GIMP
4. Blender and Firefox/PDF
5. Various combination of listed apps.

All of those examples can benefit from multiple cores and threads, and none of them exceed 4 apps. Having those cores would speed up my ability to work, having more cores isn't going to increase how quickly you browse in firefox, scroll in a PDF, or open a header file.

 

[Marcus52]

Nice article, thanks toms! This is the kind of thing I love to link to forums to answer questions and back up my opinion with a little fact.

It might not help your current game to run 4-cores, but what if you run AVG, for example, and the game too? clearly the 4th core will help gamers currently, even if not directly.

Speaking of AVG, I'm glad to see that their latest version has a bit of a reason to be sluggish on my dual-core system. While I still think it's a bit bloated compared to its past versions, being built to take advantage of modern technology is a good thing in software deployment.

 

[enterco]

[citation][nom]Marcus52[/nom]Nice article, thanks toms! This is the kind of thing I love to link to forums to answer questions and back up my opinion with a little fact.It might not help your current game to run 4-cores, but what if you run AVG, for example, and the game too? clearly the 4th core will help gamers currently, even if not directly.Speaking of AVG, I'm glad to see that their latest version has a bit of a reason to be sluggish on my dual-core system. While I still think it's a bit bloated compared to its past versions, being built to take advantage of modern technology is a good thing in software deployment.[/citation]
Almost everyone has an AV on background running, but I never heard of gamers running full system scan task when they play ;-)

 

[Guest]

The comparison I have found valid on my computers is to take the clock speed and multiply by the number of cores to get an equivalent single core speed, which result closely correlates to my subjective user experience. A 2 core 3GHz becomes 6GHz, and a 4 core 2.33GHz becomes 9.32GHz. On single core I would find myself using 2, or sometimes 3, machines simultaneously because they were so slow. So in my experience I would say single core is pathetic, dual core is almost usable, 4 core is nice and I am happily anticipating 16 core.

 

[filip007]

How many 2 is just fine and save power at same time.

Photoshop have all test the same with 1,2,3,4 core/s that is lame.

CPU,HDD,RAM this stuff is at end of speed and GPU will be soon.

 

[shady28]

Ditto the comments about higher clock dual cores vs slower clocked quads, and price comparisons. For what the article is attempting to do, it's done wall, but mention of the price vs performance of duals and quads should really have been given a nod in the article.

It isn't only games where faster clocked duals shine either. Many of the most common applications, like iTunes, will run faster on say an E8400 than on a Q6600.

 

[Guest]

You can disable cores in bios if your board supports it. Also, it's not just about clockspeed either, but about bandwidth.

A Celeron with 128k of processor cache, OC'ed at 3.2 Ghz is going to perform like a whip even compared to a 1st generation P4 (single core, non-hyperthreading) running at half that clock speed. My fiance's computer was running at 3.2Ghz yet the processor wasn't even powerful enough to play 640x480 H.264 video in VLC player. I upgraded to a HT Prescott 3.0Ghz stock speed, and now playing back that same video consumed less than 10% CPU resources.

Clock speed means nothing if the memory, cache, or system bandwidth can't keep up.

 

[Guest]

Today generation of geek is sad. Now when new tech comes out instead of showing awe and discussing possible applications, all you fake enthusiast do talk about how you don't need it.

Do you guys also go to car shows and say "all anyone really needs is a KIA"

We would still be living in caves if were up to you kids.

 

[enterco]

[citation][nom]algk[/nom]... all you fake enthusiast do talk about how you don't need it.[/citation]
The question was: "how many cores do you need?", not "what could you do with all the cores in the world. The answer to that question can be... Seti@home? Folding@Home?

 

[Guest]

@enterco

that's the problem

if it's about what "you need" then answer for "yourself" (like the article request)

not what you guys think the world needs based you what you are doing at your house.

 

[Guest]

@enterco

that's the problem

if it's about what "you need" then answer for "yourself" (like the article request)

not what you guys think the world needs based you what you are doing at your house.

 

[xrodney]

Ok score with lame is really strange as for me 1 vs 2 CPUs was huge difference (ofcourse lame encoder was executed by script to encode more then 1 file at once)
It's not necessary to encode lets say audioCD with lame track by track when you can run multiple tracks at once and save 70% time needed for encoding.

One thing is what single application can gain with 4 cores and another one what smart user can.

 

[xrodney]

Ok score with lame is really strange as for me 1 vs 2 CPUs was huge difference (ofcourse lame encoder was executed by script to encode more then 1 file at once)
It's not necessary to encode lets say audioCD with lame track by track when you can run multiple tracks at once and save 70% time needed for encoding.

One thing is what single application can gain with 4 cores and another one what smart user can.

 

[Guest]

Well, i would say that for normal usage dual core is already enough. Quad core for daily applications is overkill. If you're talking about video encoding, games( new ones like far cry 2 ) then quad core is the way to go. I will just stick to dual core for the time being and upgrade to quad core maybe 365 days from now.

www.techmostwanted.com

 

[Guest]

Erf. To channel Inigo Montoya, I do not think "begs the question" means what you think it means. Begging the question is a logical fallacy. I believe "raises the question" is the appropriate phrase.

 

[robertbradbury]

For the most part you are not trying applications that could *really* use multiple CPUs. For example run a OS that supports virtual machines, such as Xen, then run Windows on one VM, and Linux on another VM and run simultaneous benchmarks on *all* of them. Preferably identical benchmarks, a number of which are available on Roy Longbottom's PC Benchmark web site. You could also "push" on things a little bit by running the benchmarks in emulators (cygwin under Windows and wine under Linux). Now that would be a true test of multi-core abilities.

 

[enterco]

[citation][nom]robertbradbury[/nom]... For example run a OS that supports virtual machines, such as Xen, then run Windows on one VM, and Linux on another VM and run simultaneous benchmarks on *all* of them..... Now that would be a true test of multi-core abilities.[/citation]
It would be interesting to see such benchmarks, but that kind of benchmark would require some other things which the home user (main audience of this kind of article) do not use: workstation/server class computer / SAN / Virtualization etc...

 

[kaigypsy]

This article plus some of the comments helped me decided what to put into my first build. Easy to understand with not too much techno speak for the nearly completely noob. Thanks!

 

[ternovoygarri]

if for example a CPU has 4 cores - it nedded to be a fifth core for multiplexing instructions to the rest of four

and from OS level - it would be a single core

 

[ImSpartacus]

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.

 

[bboysil]

I just want to add that a single core cpu (that was built as a single core from the start) may be faster than a multi core cpu at the same frequency (let's presume they have the same core architecture).
A reason is for example cache hit time is larger on multicore because of the structural hazard (multi core accassesing the same L2 cache) and synchronization between l1 caches...

 

[bboysil]

In my previous post I was referring to the multicore with a core disabled... and of course the difference in performance is little.