How Many CPU Cores Do You Need?

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Hence, the latest AMD X3 CPUs perform very well against C2Q and i7-920 CPUs. The GPU becomes more important... of course, if someone can afford a quad, might as well... it usually doesn't hurt.

But a X3 $120 chip that is able to play a game at 80fps vs a $300~600 i7 CPU with a Mobo that costs x3 times the price gets about 90fps... the return on your "investment"(which computer tech is not) is on the X3. The money saved can go towards a higher end video card where it really matters.
 
True I would agree that the short-term adv goes to X3/AMD in this pricing segment... BUT for long term (if you're like me) and don't upgrade until it's more a necessity vs frivolity: AMD's platform/roadmap is largely unforeseen Vs intel which with C2D, QX, i7Core and more to come, has largely proven that if you invest your money with Intel, you WILL get what you see, and it will stay viable with future upgrades (course new socket will omit this adv).

I'm pulling for AMD to topple Intel, BUT I'm still unsure about their ambiguous performance roadmap. They NEED to keep making truly competitive products in order to re-cement their brand.

Meanwhile I'm on my trusty OC'd XP! 8yrs OC'd, still passing PRIME95. Value?
 
I think a dual core processor is good enough for most people.
If you're a gamer, or use thread optimized heavy applications like a thread optimized photoshop or CADprograms, you hit the sweetspot with 3 cores.
Although using 3 CPU cores probably has a larger benefit due to the shared cache between core 3 and 4?

Eitherway, the way the benchmarks show, if a 3 core costs less than 75% of a 4Core, I'd go with the 3Core for gaming.

With the upcoming processors a 2Core with HT enabled will do about everything, and perform like a 3core.
 
[citation][nom]apache_lives[/nom]yet again - no one uses a fresh install platform (windows) with nothing else running - we all have MSN, Torrents, Antivirus, windows update, web browsers running, steam, ea games manager running etc - all chew up performance!Real life the quads (and better etc - Core i7) would stand out furtherI remember THG had a video - 3.6ghz vs 3.06ghz with HT - unreal tournament 2003 with some other heavy app running showed that with HT is was doable vs non ht - thats the stuff im talking about!Next article - how many apps can run while you game! Phenom 1/II vs Core 2 vs Core i7 etc - find the real benefits of a megatasker etc not just one app at a time like we all DONT do. Oh and also Vista and XP and maybe Win7 somewhere in there[/citation]


I recently did a big upgrade to an I7 box running with a minor O/C of 3.4GHz. Just for laughs I decided to run both Left4Dead (started a game & let bot take over) & Far Cry 2 (demo run) at the same time in windowed mode side by side (both 1024x768) while also buring a DVD & doing some file downloads....
1)I couldn't beleive I could actually do this...
2)When I checked task manager, it said I still wasn't using 75% of avaiable CPU time...

Now if only more games would allow you to switch to the desktop & back without issues you could REALLY multi task...

Seriously, software development seems to be lagging hardware but just how much parallelism can you use on a desktop...?

Where are all the killer multicore apps?

I think it's about time speech recognition made a comeback, either using CPU miltcore or GPU streams?

 
Nice article.

I would have to agree with apache (shocking as it may be) that I would have liked to have seen the performance of Windows XP vs. Vista. Vista handles multi-core better that XP, so how much would 3 or 4 cores affect anything.
 
Vista handles multi-core better that XP
Click to expand...
This is proven by what? The bloat of Vista wipes out whatever SMP advantage it has over XP. Vista WILL always requires at least 4GB to equal a 1GB XP box. Keep in mind that bottom end $350~400 PCs have 3GB.

True I would agree that the short-term adv goes to X3/AMD in this pricing segment... BUT for long term and don't upgrade until it's more a necessity vs frivolity: AMD's platform/roadmap is largely unforeseen Vs intel which with C2D, QX, i7Core
Click to expand...
How often does that REALLY work? Invest PC tech for the future? You can plan for upgrading up to a small point... ie: install a better 3D card, bigger HD. But the CPU/RAM/Mobo... more limited.

The original P4-Socket 423: Some people bought these "for the future" with 1.6Ghz $1000 CPUs that were SLOWER than AMD or P3 @ 900Mhz. Worse, it wasn't a great secret that Socket423 was limited to about 12months. 478 replace it... but as chips got faster, newer motherboards were required. Then the move to Socket 775, etc. Very soon, Intel will have 3 different sockets on the market - completely incompatible. If a person buys a C2 or i5-CPU, they have to replace everything for an i7.

argely proven that if you invest your money with Intel, you WILL get what you see
Click to expand...
The Intel P4 always lost out to AMD32/64/X2 CPUs (except in video encoding and some 3D rendering) Check the benchmarks on this site. The $250 AMD 2.2Ghz CPUs were equal or faster than a $1000 Intel. Ouch, very BAD investment. Look at the uninformed (or people who like to brag about having a 4000Mhz CPU) in early 2006, who spent $2000 investment in an Intel Pentium EE computer when a $600~800 AMD (low-end) was just as fast. Then for Intel to come out with Core2 at about $200 that destoryed any P4/D/EE and knocked AMD off the throne. Had you bought a mobo that was 6~12months before C2D, then it was most likly not compatible and of course owning a Dell or HP meant no upgrade to C2D anyways.

A person can buy an AM2+ board and use an AM2 or AM3 CPU that is 1,2,3 or 4 core CPUs at $40~250. A person who spends $200 for an X2AMD (2.6~2.8Ghz) 4GB RAM and motherboard can pocket the change and get decent performance... more so with an X3 CPU. Vs $650~700 for an i7/mobo/RAM... In 1-2 years, that same $700 setup maybe $200.

I own a Core2Quad... if I was building my own PC today, it'd be an AMD. Buying a new Core2 is fine, but there is NO upgrade from there. If AMD can some make their 6~8core CPUs work in AM3, that would be an amazing feat. AMD is coming out with a 1974 pin socket! Thats for servers. :)
 
dude who is screaming his brilliance if you look at the variety of test and their individual results you should be able to come up with a conclusion. If each type of application is getting significant boost individually as you have more cores consequently using them together on a multi core system vs single core will provide a marked improvement, a superior article I think. I will save my money and go triple core :)
 
[citation][nom]Twoboxer[/nom]Great article. Useful. Some thoughts:- glawk et al need to consider total system cost, ie:In a $1500 E8500 system, the $140 premium for a Q9650 yields an 11% performance increase for a 9.3% increase in cost. No terrific, but the point remains.
[/citation]
If I would use a graphics card which costs $100 more, I would achive a better gaming performance than by using a CPU which costs $100 more.
 
[citation][nom]mikewalker[/nom]Actually I do exactly that, as do many others - don't make such broad generalizations! It's quite obvious that for now and the foreseeable future a fast dual core CPU is the best option for the vast majority of computer users - for example, running an e8400, stock volts overclocked to 3.6 ghz! Try that with a quad core! Fast performance, low price and energy savings - we have a winner folks! In my opinion the best overall values right now are the e5200 and Kuma 2.7GHz, made by Intel and AMD, respectively. Both can be very nicely overclocked and will handle almost any task perfectly.[/citation]

My multitasking and heavy usage makes the E6600 @ 3.2ghz no match for even my Q6600 at stock

Is there a reason why lately people are hating higher performance items like SSD's, Core i7's, Quads, etc?

[citation][nom]jeRrRKKKK[/nom]should have used a phenom 2 for testing instead. the c2qs are not native quad cores, they are native dual cores pressed together... thus the results would be dual core biased.[/citation]

Idiot

[citation][nom]MotifatorEx[/nom]he does have a valid point tho we allways have somthing running in the background.[/citation]

Exactly my point - fresh install is BS when the real world we have 10x the stuff running

[citation][nom]jasonstokes[/nom]This is a great article. and it is great to see that some applications do use all the cores efficiently. I run a AMD 720 with Ubutnu 8.10 the one thing I love about my 3 core systems is if an application only using 1 or 2 core (as some do), I still have head room to run other application. with more cores it just means I can do more things at the same time....[/citation]

And whats wrong with yet another spare core?

[citation][nom]trinix[/nom]I think too many people want to hear, you have to buy a quad core, because they got one.I'm sorry, but the average Joe should buy a dual core. He has no use for more than 2 cores at all.For gamers it's different. They can either go dual or triple, with triple giving the best advantage for today's games.Are you into video editing and other heavy cpu programs that require a lot of cores, yes, a quad core probably i7 is best for you.Next year? Who knows. I can't tell you what we will see next year, but this year I don't really see a lot of changes in software except for win7. If you can get a faster dual core or triple core, you will get better performance than going for a slower quad core in games and desktop application not optimized for 4 cores. You have to know what you use it for. I'm not saying a quad is useless, just think that a dual and triple give more bang for the buck, especially for people who are on a budget.[/citation]

If the average joe can get a quad for a few $$$ more then thats the chip for average joe. 10% slower in single/dual threaded apps (clock speed) vs 50+% faster in multithreaded is better, plus future proofing etc

[citation][nom]rickzor[/nom]omg, does this means that my pentium III tualatin @ 1.32ghz on my bx440board from 1999 isn't good enough for games already? :0[/citation]

BX440 boards dont usually nativity support FSB133 130nm cpus, the 815E series chipsets addresses those issues (modern socket, proper agp/pci ratio for FSB133 etc)
 
You should change the audio program from Lame/Itunes (Itunes is lame) to DBPoweramp. DBpoweramp will successfully make use of however many cores are available, successfully encoded same CD on AMD720BE (stock) 1 min. 22 sec. Ditch the ITunes, this is an enthusiasts site.
 
You forget the Main reason why some of us use more than one core...

!!! MULTI-TASKING !!! (or as apache points out MEGA-TASKING)

With multi-core, goone are the days when I can only do one thing at a time. We're encoding, transcoding, archiving, mirroring, recording, scanning, and syncing IN THE BACKGROUND. None of these tasks affect my computer responsiveness or it's ability to perform it's main duties: e-mailing, printing, researching, etc...





 
You forget the Main reason why some of us use more than one core...

!!! MULTI-TASKING !!! (or as apache points out MEGA-TASKING)

With multi-core, goone are the days when I can only do one thing at a time. We're encoding, transcoding, archiving, mirroring, recording, scanning, and syncing IN THE BACKGROUND. None of these tasks affect my computer responsiveness or it's ability to perform it's main duties: e-mailing, printing, researching, etc...
 
Some other posters made mention of the Q6600 being composed of 2x Core2 Duo dies in one package and having separate L2 cache for each. That results in NUMA (non-uniform memory access). That explains part of the reason the increase from 2 cores to 3 cores is smaller (than 1 to 2 or 3 to 4) on some tests. Windows scheduler is pretty dumb when it comes to scheduling tasks on the same CPU/Core as previously used.

With 1-2 cores on this CPU, the L2 cache is shared and the effect of a task switching between those 2 cores is minimal. However, when you allow that 3rd core, you're also switching to another die and another L2 cache, which will result in a significant performance hit in many situations. Moving from 3-4 can make that issue better or worse depending upon how many threads are active, how much data is shared between the threads, how much data is "typically" used by each thread, how often thread switches occur, etc.

The Core i7/i5 CPUs use a small L2 cache and a large shared L3 cache for their quad core models, so those would likely see better scaling from 2 to 3 and from 3 to 4 cores active.

Of course, smarter scheduling in Windows would help.

Hyperthreading may provide addition performance in certain circumstances, but HT would work best with smarter scheduling, since Intel's implementation of HT results in a type of Asymmetric Multi Processing (AMP), not Symmetric Multi Processing. It's SMP in the sense that any CPU/core can perform any task, however, not all cores are equal in performance, so it's asymmetric performance. Scheduling a thread that needs high performance and/or low latency on one of the "virtual" CPUs, will generally result in lower performance. That makes performance using HT difficult to predict or duplicate.
 
My PC mirrors the results. My Q8300 never gets above 20% normally even when running GIMP, and I have never seen it over 80%. 3 cores take the bulk as you pointed out, with the fourth running some Vista background tasks.
 
I agree with allot of the other postings, an excellent article, very good information, and Don put allot of effort into this work, good job. 🙂
 
I'd like to see how well it can compress files with the 7zip application using LZMA compression. 7zip's website says "Supporting multi-threading and P4's hyper-threading" as one of the bullet points. Here is my result on a lowly Core2 T7300, CPU profile set to Performance in Ubuntu 9.04:

7-Zip 4.65 Copyright (c) 1999-2009 Igor Pavlov 2009-02-03
p7zip Version 4.65 (locale=en_US.UTF-8,Utf16=on,HugeFiles=on,2 CPUs)

RAM size: 2012 MB, # CPU hardware threads: 2
RAM usage: 425 MB, # Benchmark threads: 2

Dict Compressing | Decompressing
Speed Usage R/U Rating | Speed Usage R/U Rating
KB/s % MIPS MIPS | KB/s % MIPS MIPS

22: 2490 153 1586 2422 | 30211 191 1426 2727
23: 2425 152 1620 2471 | 29868 194 1407 2734
24: 2409 156 1657 2590 | 29572 194 1415 2744
25: 2351 154 1741 2684 | 29421 195 1418 2767
----------------------------------------------------------------
Avr: 154 1651 2542 194 1417 2743
Tot: 174 1534 2643

Show me what you can get with newer and faster processors.
 
I have a dual core, but think i'd be happier with a quad.

a high clock dual is ok for games, but it seems a quad is a lot harder to bog down with multitasking.
 
I have a quad Q6700 and was wondering if I disabled 1 core would the cpu use less power and less heat(so I can overclock higher for gaming).
Cause sounds to me like:
3 core 3.4Ghz > 4 core 3.0Ghz
 
I wish they had tested applictions running parallelly also . How would the games be running if some video compression work was going on in background.
plus there is no mention of whether the future games and applications would use benifit from 3 to 4 cores.
 
I'm sorry, but most of the multi-tasking examples here are rather silly.

I can easily see encoding musics will doing something else (watching a movie, listening to music, playing flash games), but adding yet another action on top of that is just unrealistic.

The fact of the matter is, more cores are for multi-threaded applications. However, quite a few mainstream apps now a days are dual-threaded (video and music encoding, games, archive managers, media players, etc). So using a dual threaded app like a music encoder leaves only 2 cores left for you're OS and it's backgroup executables, anti-virus, and whatever you plan to use while waiting for the encoding to finish.

If you multitask and use multi-threaded apps then a Quad-core makes sense.
 
I remember way, WAY back when Intel introduced HT Toms HW ran tests to measure the benefit for users. The tests included running multiple apps at the same time and recording the time, framerate, etc. Why aren't these type of tests performed for this article? It seems that only multithreaded applications were considered and not concurrent applications on a mutithreaded OS. I'd like to see this in a follow-up article.
 
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