CPU - Single Core, Dual Core, Quad Core? WTF?

Guys (and girls), I need some info please.

I am sitting with a couple of server specs in front of me (about 8 to be exact). Now, the requirements (for the SW) state:

Single Core CPU: 2-4
Dual Core CPU: 1-2
Quad Core CPU: ?

I cannot imagine that the relationship between the different cores will be a straight multiplication factor, or am I missing the bus here? If that is true, the ? above can be replaced by 0.5-1 ?

Single core CPU: cook an egg in 4 minutes when run without heatsink.
Dual core: cook an egg in 2 minutes....
Quad core: cook an egg in 1 minutes....

I don't understand your question. But I hope you understand my statment above.

I am trying to figure out if there is a linear relationship between the cpus:

If I require 2 X 2Ghz single core CPUs, instead of using that as per the requirement, can I replace it with a 2Ghz dual core CPU? IE will I get the same performance from the Dual core are I would with 2 single cores?

I guess there are many factors which will influence such outcome, such as your server application, platform it's running on .etc. But yes, most of the time you can put it like that to simplify the matter and it will give you more or less similar result....

Let's wait for other expert's opinion.

I would probably work out cheaper to get the dual/quad core with a single socket motherboard, than a dual/quad socket motherboard which cost a lot more due to lower volumes being manufactured, and the performance will be the same...

Ok...Let me explain in "layman's" ( the outjie in the street ) terms
First of all, what does all the "core" stuff mean? Dual core = 2 cpu's in one....Quad Core = 4 cpu's in one. Lets say you buy a Dual core 1.8Ghz....Its like having 2 Dutsan's, both with an average speed of 180km/hour...Lets say i put them together at a starting line...Now, i take the first Datsun, and let it excellerate from 0 to top speed...The top speed will be ( roughly speaking now ) lets say 180km/hour..Now the 2nd Datsun also pulls away reaching 180Km/hour as well...How fast are they driving?...well, STILL only got a speed of 180Km/hour. to explain further, lets asume each car carries 4 people ( Data ). Now i got 8 guys seeking a lift...I can put 4 in the one, and 4 in the other car and ask them to pull away at the exact time...it now takes the people X amount of time from point A to point B if BOTH cars do the job...If i still had 8 people, but only ONE car TO DO THE JOB, itll take them TWICE as long to reach point B...See the diff? BUTTTT...What happens if i only got ONE lane of road? Still going to take them twice as long...And if there were 2 lanes?...obvously half the time to get to B...This is where the "snag" comes in...You still get a lot of software that can only use 1 cpu ( ie 1 lane )...so its better of getting a faster car to move the guys ( data )...BUT, seeing all software will most likely be using more cpu's ( lanes ) to access their data, dual...quad or whatever is best....ie if i have a single core cpu 3Ghz, and compare it to 1 Dual core ( 2x 1.5Ghz each ), it WILL outperform the dual ONLY IF MY SOFTWARE CAN ONLY HANDLE 1 LANE...cause my DUAL can only handle 1.5Ghz per lane...the other cpu of the dual will lay dormant ( well sort off )...Hope this gives you more of an idea?...This is just a VERY basic way of explaining

Maby this will give you an idea why your "buddy's" 3ghz outperforms your Dual 2.4Ghz on older games?
So the answer here is basicly this...If youre running SERVERS ( which i think all uses more than one "lane" ), Quad ( or better ) is the way to go

LandyMan said:

I am trying to figure out if there is a linear relationship between the cpus:

If I require 2 X 2Ghz single core CPUs, instead of using that as per the requirement, can I replace it with a 2Ghz dual core CPU? IE will I get the same performance from the Dual core are I would with 2 single cores?

Click to expand...

Well....more or less...it also depends on the type of technology involved...Personally id say the dual core will outperform the 2x Single core on the LATEST software

...and just to revive it, os/2's multithreading was way better than windows's multithreading

But back to the topic.

The more cores your CPU has, the more work it can do in less the time. The general idea is to build one mongo server with 2 or 4 quad core CPU's - then use virtual PC to run virtual servers on that one server - thereby minimizing server room clutter.

We're moving towards such a setup - and it is good to eliminate several servers in one go and consolidate them on one big server but it reminds myself of the IBM mainframes of old - where one big piece of iron runs everything

Of course the big plus of virtual servers is that you can allocate CPU and RAM resources as needed so you can balance the system quite nicely.

Robin Hood said:

Ok...Let me explain in "layman's" ( the outjie in the street ) terms
First of all, what does all the "core" stuff mean? Duel core = 2 cpu's in one....Quad Core = 4 cpu's in one. Lets say you buy a Dual core 1.8Ghz....Its like having 2 Dutsan's, both with an average speed of 180km/hour...Lets say i put them together at a starting line...Now, i take the first Datsun, and let it excellerate from 0 to top speed...The top speed will be ( roughly speaking now ) lets say 180km/hour..Now the 2nd Datsun also pulls away reaching 180Km/hour as well...How fast are they driving?...well, STILL only got a speed of 180Km/hour. to explain further, lets asume each car carries 4 people ( Data ). Now i got 8 guys seeking a lift...I can put 4 in the one, and 4 in the other car and ask them to pull away at the exact time...it now takes the people X amount of time from point A to point B if BOTH cars do the job...If i still had 8 people, but only ONE car TO DO THE JOB, itll take them TWICE as long to reach point B...See the diff? BUTTTT...What happens if i only got ONE lane of road? Still going to take them twice as long...And if there were 2 lanes?...obvously half the time to get to B...This is where the "snag" comes in...You still get a lot of software that can only use 1 cpu ( ie 1 lane )...so its better of getting a faster car to move the guys ( data )...BUT, seeing all software will most likely be using more cpu's ( lanes ) to access their data, dual...quad or whatever is best....ie if i have a single core cpu 3Ghz, and compare it to 1 Dual core ( 2x 1.5Ghz each ), it WILL outperform the dual ONLY IF MY SOFTWARE CAN ONLY HANDLE 1 LANE...cause my DUAL can only handle 1.5Ghz per lane...the other cpu of the dual will lay dormant ( well sort off )...Hope this gives you more of an idea?...This is just a VERY basic way of explaining

Maby this will give you an idea why your "buddy's" 3ghz outperforms your Dual 2.4Ghz on older games?
So the answer here is basicly this...If youre running SERVERS ( which i think all uses more than one "lane" ), Quad ( or better ) is the way to go

No

Click to expand...

I like this explanation, but I'd like to add to it. You WILL ALWAYS benefit more from a 1.5Ghz Dual Core than a 3Ghz single core CPU. Even if you run 8 / 16 / 32 bit applications, that are not multi core aware. Why? Cause you will most defenately run more than 1 APP on your server at any given time. In a server environment, your SQL DB's will use 1 core, where the web server can use another. If this was a dual core, it will use all 4 cores effectively. Remember, every connection to the server (either from the web, or to shares from the LAN, or email clients, or anything) will create new threads, which will be spread out among the cores. If you can afford it, go quad core. Get at least 800Ghz DDII, OR even DDRIII RAM if the mobo & budget supports it

dont go ddr3

you get a 10% increase but its like 1000% more expensive

price/perforance is totally off

SoftDux said:

Why? Cause you will most defenately run more than 1 APP on your server at any given time.

Click to expand...

Very very very true
Also for multi-tasking this is excellent.