why i5 with no hyperthreading outperforms i3 with hyperthreading?

vikyy17

Estimable
Oct 8, 2015
9
0
4,510
i3 is a dual core CPU with 4 threads i.e two threads per core. i5 also has 4 threads but a quad core CPU, one thread per core. then how is i5 faster?
 
Solution
because hyperthreading is not a true core. it is a way to ensure that the single core is fully utilized. so essentially hyperthreading makes sure the dual cores run as close to 100% as possible, thereby improving performance.

the cpu does things in series. meaning one at a time. if there is a break in the commands sent to it, then it waits idle until it gets a new command to carry out. hyperthreading keeps extra stuff waiting and fills in these breaks keeping the cpu busy.

a true 4 core cpu has exactly that, 4 full cores each doing as much work as possible. which is twice as much works as is possible for a dual core of the same type. an i7 adds hyperthreading to the i5's 4 cores and improves the performance the same way. ensuring all...

Quixit

Estimable
Dec 22, 2014
62
0
4,610
Hyperthreading is just a hardware feature that manages threads, it doesn't add additional processing units. Those are called cores, because of this a quad core should outperform a dual core with the same architecture and frequency regardless of how many hardware threads it supports.
 

Math Geek

Estimable
Herald
because hyperthreading is not a true core. it is a way to ensure that the single core is fully utilized. so essentially hyperthreading makes sure the dual cores run as close to 100% as possible, thereby improving performance.

the cpu does things in series. meaning one at a time. if there is a break in the commands sent to it, then it waits idle until it gets a new command to carry out. hyperthreading keeps extra stuff waiting and fills in these breaks keeping the cpu busy.

a true 4 core cpu has exactly that, 4 full cores each doing as much work as possible. which is twice as much works as is possible for a dual core of the same type. an i7 adds hyperthreading to the i5's 4 cores and improves the performance the same way. ensuring all 4 cores run as close to 100% as they can with the same technology.
 
Solution

zeke15

Estimable
Jan 27, 2016
10
0
4,570
To put it simply, Cores are better than threads. THe i3 has 2 cores and 4 threads, the i5 has 4 cores and 4 threads. i5 has more so it is better. This is a very simple way of saying it, but to this situation it applies.
 

firefoxx04

Distinguished
Jan 23, 2009
40
0
18,590
Both have "4 threads" but the i5 has 4 real cores while the i3 only has 2 cores.

Also consider that the i5 might have a higher clock speed and more l3 cache. Hyperthreaded cores are not faster than real cores.

The question is kind of silly, one might think that both chips would perform the same.. not think the i3 is faster. Both have 4 threads, if hyper threading was capable of delivering 100% more performance per core, then they would be very close in performance and an i7 would be twice as fast as an i5, which is NOT the case.