multi core processor performance

[sukesh1090]

guys my question is that, if we take a 2.8GHz dual core processor and a 2.8GHz quad core processor which one perform better?why though they are of same speed?do there will much difference in performance?

 

[coderunknown]

^^ depends on many more factors too. & yes on the kind of use.

 

[sukesh1090]

i didn't understand what you said.can you please explain that which is better and why?

 

[coderunknown]

in gaming:

1. high clock rate. irrespective of dual or quad. a 3Ghz C2D will beat a 2.66Ghz C2Q.
2. higher L2 cache & if possible, L3 cache. Q9550 or of same variant beats C2Q8***.
3. newer generation proccy are faster than old gen proccy even if speed is higher on the old one. eg: Core i3 beats Athlon II X2 as well as Phenom II X2, even if the AMD have high clock.

but if the use is something like encoding or highly threaded apps like animation, quad core or 6core proccy is obvious choice.

 

[sukesh1090]

k i got it.thank you.if we take intel pentium dual core E5500 @2.8GHz and AMD Athlon 620 quad core @2.6GHz which one will give better performance?

 

[coderunknown]

Athlon II X4 will be slightly faster in single threaded apps (cause its clock rate is lower than the DC) & considerably faster in multithreaded apps.

 

[sukesh1090]

but you told high clock rate will be better in your second post.

 

[desiibond]

let me ask you few questions, from which you will find answers:

Take a scenario where 12 bricks, each brick about 5kgs in weight need to be carried from one place to another, distance being 500 mtrs (for example). One person can carry only one brick at a time. Which of these will be fastest way and the speed with which the bricks can be carried depends on person's stamina.

1. one athletic person carrying bricks.
2. Two athletic people carrying bricks.
3. Four athletic people carrying bricks.
4. one kid carrying bricks
5. two kids carrying bricks
6. four kids carrying bricks
7. 20 athletic people carrying 10 bricks
8. 20 kids carrying 10 bricks

 

[sukesh1090]

the 7nth one.but iam too sorry to tell that i didn't understand anything.

 

[ssb1551]

but you told high clock rate will be better in your second post.

Yeah I guess it was a typo on Sam's part.What he meant to type is this :
" Athlon II X4 will be slightly slower in single threaded apps (cause its clock rate is lower than the DC) & considerably faster in multithreaded apps."
Is it ok now for ya?

 

[sukesh1090]

k and what about games?

 

[ssb1551]

@ desiibond - I get the "athletic" & "kids" analogy.Athletic referring to CPUs of higher clock speeds & Kids referring to CPUs of lower clock speeds.Even the 1/2/4 as cores in CPUs but whats with the "20 athletic people carrying 10 bricks"?Whats that supposed to signify?

 

[NainO]

Quad core excels on multithreading...
And for singlethread operations three things comes into consideration
1. Clock speed
2. Bus speed and
3. Cache memory
Higher these things - higher the performance!!7

 

[ssb1551]

k and what about games?

Most of the games we know use 1/2 cores.I think present day games are trying to use 4 or more cores & in future I believe they'll do so.So for gaming CPU should have high clock speeds & higher L2/L3 cache.
Guys please correct me if I'm wrong.

 

[sukesh1090]

@ desiibond - I get the "athletic" & "kids" analogy.Athletic referring to CPUs of higher clock speeds & Kids referring to CPUs of lower clock speeds.Even the 1/2/4 as cores in CPUs but whats with the "20 athletic people carrying 10 bricks"?Whats that supposed to signify?

yes that is where i also got confused.

 

[arpanmukherjee1]

processors are invariably multicore. there r many factors on which the performance is measured

see Computer performance - Wikipedia, the free encyclopedia

>clock speed
>cpu max voltage
>cpu architecture
>cache
>application
>HT support

if ur application can take advantage of multi core processor and HT (hyperthreading) then it will run effectively as clock rates and cores increase.

if application is single threaded more cores will not effect performance

next is cpu architecture. dual core and quad core r different in architecture and will perform differently under different instruction set or commands.

cpu design is complex topic and comparing two cpus on one or two factors is not appropriate.

the best way to find your cpu is to keep the cost factor and your need in mind and refer bench/statistics from Digit or anandTech etc..

 

[coderunknown]

but you told high clock rate will be better in your second post.

BUT, Athlon IIs architecture (derived from Phenom II) is much better/newer than the dual core. so it excels or at least is equal than the DC, even when its 200Mhz slower.

so, a 3Ghz P4 looses to a 2.8Ghz DC. not going into details but this is what should be the end result. what i mean is, other than the clock, cache memories, transistor counts, the architecture plays a major role (better architecture + less transistor = old architecture + lots of transistor).

Yeah I guess it was a typo on Sam's part.What he meant to type is this :
" Athlon II X4 will be slightly slower in single threaded apps (cause its clock rate is lower than the DC) & considerably faster in multithreaded apps."
Is it ok now for ya?

nope. it wasn't a typo

 

[desiibond]

@ desiibond - I get the "athletic" & "kids" analogy.Athletic referring to CPUs of higher clock speeds & Kids referring to CPUs of lower clock speeds.Even the 1/2/4 as cores in CPUs but whats with the "20 athletic people carrying 10 bricks"?Whats that supposed to signify?

that means 10 will be carrying bricks while other 10 will sit idle, not doing anything.

same scenario for apps that dont' use multi cores

 

[ssb1551]

nope. it wasn't a typo

HOLY CRAP!!My Bad!!!