Number of CPU's

If you mean cores, they do matter, but they arent the only thing to consider.
In times coming 4 cores has become "baseline" there are 2 core CPUs that are still performing, but technology is moving on.
6+ cores are valuable in certain cases, but not all.

Please elaborate. Are you talking about cores or actual CPU chips in a multi-CPU motherboard system that are sometimes found in servers?

To add to that and make it a little more simple and a little more complicated.

Yes number of cores or CPUs does matter. Two is considered a minimum, while four is considered optimal usually. Sometimes having more than four helps, but how much boost you get from those extra cores isn't as big as when you go up to four.

Also when looking at AMD and Intel there is a difference here, very long story, so if you want to know more you will want to learn about specifically which one you are curious about. To put it simple though, four cores is still usually best.

When talking about multi-core CPUs you also have to look at single core performance. Just because a CPU has 4 cores doesn't mean it is better than every dual core CPU or even single core CPUs - although that also depends on the application and if the user is a heavy multi-tasker. The new Haswell Pentium, for example, is only a two core, two thread CPU and is a faster overall CPU than some of the old Core 2 Quads. There are many low powered quad CPUs as well that are found in phones and tablets from ARM, Nvidia and Intel's new Baytrail Celeron line. Any of those CPUs would easily be beaten by an average dual core desktop CPU and even some of the last single core Pentiums 4's that came out. But those phone and tablet CPUs use something like 1/100th the power and produce about that much less heat.

You should be careful how you say things. There isn't a single core CPU that exists than comes close to the speed of anything made in probably the last 6 years. Simply put more cores are better. Yes there is a lot more to look at when it comes to determining performance, but strictly speaking a quad core will be better unless you are comparing between devices which are not really similar. You are best not to put so much information to avoid confusing the original poster.

So you are confident that not a single quad core mobile CPU made since 2007 such as the Snapdragon S4 could lose to a single core Pentium 4 with hyperthreading in a single threaded benchmark test? What about a current dual core desktop CPU like the Pentium G3258? The OP edited his post and his CPU is a Pentium N3530. The dual core G3258 is double the speed of the N3530 with only half the cores (and threads). You still want to say that "a quad core will be better" "strictly speaking"? Those CPUs are used in similar devices. Both are in computers that are running Windows.

Well going back as far as Pentium 4 single core, yes I am pretty confident any quad core CPU even one meant for a smart phone would out perform it. Those things were painfully slow when they were new. In single threaded benchmark test it might lose, but overall performance I am sure it would win.

As for comparing the Pentium N3530, which is really designed for tablets not PCs, making it a device which isn't similar really, its a completely different field. They get used in laptops and desktops as integrated units but they aren't designed with that environment in mind.

However if you compare any quad core CPU made by Intel be it Sandy Bridge, Ivy Bridge, Haswell, or Broadwell or quad module CPU made by AMD, when it comes from a desktop or from a laptop, against any single or dual core CPU ever made including the Pentium G3258 they will have better performance every single time.
The only time this wouldn't come in as true is when you are looking at a device which is designed for tablets, such as BayTrail devices or AMD Mullins, fake quad-cores like AMDs FX-4300, or CPUs of significant age.

So yes strictly speaking more CPU cores are better. There are exceptions to that, but instead of trying to describe the difference between every CPU and type of CPU made since 2006 and most likely just confuse the OP, it was easier to say more cores are better

This is probably what you need to read: http://en.wikipedia.org/wiki/Multi-core_processor. If you are wondering if four cores is the same as having 4 separate CPUs, it is to your operating system. But, unlike having four separate physical CPU units, your CPU's cores share everything such as cache, RAM, voltage regulation, etc. The significance of having a quad core CPU depends on the applications you use. The apps must be written to take advantage of multiple threads working together at the same time. Most newer apps will take advantage of multiple cores and perform better in a quad-, hexa- or higher core system of the same architecture and clock speed. But, the same app will still run faster on a dual core CPU if that dual core CPU has much faster and more efficient performance of each individual core. The blanket exclamation "all quad core CPUs made after so and so year > all CPUs with less than 4 cores" is simply not true. Your CPU, the N3530, for example is a relatively low powered CPU even for laptops and is also found in desktops. There are many dual core laptop and desktop CPUs that can easily outperform it. Take the G3258 for example which is a dual core, 2 thread Pentium desktop CPU. In passmark's CPU benchmark test, it is a little more than twice as fast as your quad core N3530 (4006 vs 1954). Even looking at a mobile Haswell Pentium dual core, two thread CPU like the 3550M, it too beats your quad core CPU slightly (2135 vs 1954). This is due to the fact that Haswell is clearly a better architecture and that they pump more power into them than the low TDP Pentium and Celeron Bay Trail series CPUs. The only real advantage of your CPU is its low power consumption and low heat produced. If it is a dektop or even a laptop, you can do much better with a Haswell although it will decrease your battery life a bit in a laptop. Some popular applications for a CPU like this is as a low powered file server or a quiet and efficient HTPC. It is by no means, though, a chip capable of playing any halfway demanding games or running editing or rendering software.

The CPU can also assign different tasks that use one single core to run on a different core that is being used less so as to speed up the system. There is more to look at then multi-threaded and single threaded work load, it depends how the system works overall.

No one ever said "all quad core CPUs made after so and so year > all CPUs less than 4 cores" or even something vaguely close. I said any Quad Core CPU will give better system performance than any single core CPU. Again completely not what the user is asking about and completely off topic, but that still is very true. Single core CPUs stopped being used and created majorly after Pentium 4 and Athlon 64 for desktops. Comparing any modern desktop CPU to those things would win even if you disabled all cores but one, let alone given multiple threads. I also never said a dual core can't beat a quad core because an i3 with hyper threading will beat a proclaimed quad core CPU from AMD for almost every situation. The fact you keep trying to throw processors from smartphones and tablets in the mix to defend your point just shows you far off topic you are willing to try and go to prove your point, when this whole thing shouldn't be about arguing it should be about helping the OP.

rahul0201: To answer your question, you have a quad core CPU. The computer looks at it as though it was four CPUs but its just one with four cores. Typically having four CPUs is better. Your computer though uses a quad core CPU meant for tablets and not actually designed for computers. It gets used in laptops and desktops at times because its very cheap, but it isn't designed for it. Which means with the exception of a small handful, any modern day CPU would be faster, if you are looking to upgrade.

What having a quadcore means is there are four CPUs which can do work. If you have multiple programs open the computer will try to run the programs on a different CPU core in order to improve performance. This is where the improvement comes over having only one or two CPU cores. However, because they are low power the CPU cores only get about half the work done as CPUs designed for desktops. So a comparison of a program that uses one thread or using multiple threads all at once will be slower on this system because it is such a low power design.