How much faster is a desktop i7 than a mobile i7?

[Casper Traberg-Larsen]

I am having a discussion. How much faster is, say a, 4790k than a i7-4500u? or i7-2620m?

How many "years of performance" are mobile CPU's behind? Like, WHEN approx. will a mobile i7 be faster than the desktop 4790k? 🙂

thanks for inputs!

 

[Undying89]

Mobile i7's are more or less fast as desktop i5's. That being said, desktop i7's are on their own. No mobile CPU can be fast as desktop.

 

[Casper Traberg-Larsen]

Mobile i7's are more or less fast as desktop i5's. That being said, desktop i7's are on their own. No mobile CPU can be fast as desktop.

So.. a i7-4500U is as fast as a i5-4670?

 

[Undying89]

Mobile i7's are more or less fast as desktop i5's. That being said, desktop i7's are on their own. No mobile CPU can be fast as desktop.

So.. a i7-4500U is as fast as a i5-4670?

No, not even close. i7 4500u is a dual core with HT at 3Ghz. Its even slower than desktop i3.

 

[Casper Traberg-Larsen]

Mobile i7's are more or less fast as desktop i5's. That being said, desktop i7's are on their own. No mobile CPU can be fast as desktop.

So.. a i7-4500U is as fast as a i5-4670?

No, not even close. i7 4500u is a dual core with HT at 3Ghz. Its even slower than desktop i3.

Allright! But you're telling me, that there are quad core mobile i7 CPU's out there, which can beat a i5-4670 (example)?

 

[Sakkura]

The Core i7-4500U has 2 cores and runs at 1.8-3.0 GHz. The Core i7-4790K has 4 cores and runs at 4.0-4.4 GHz. Overclocking it to something like 4.6 GHz is realistic.

That means it has up to a 33-144% single-threaded performance advantage, or 53-156% at 4.6 GHz. The extra cores make that a 167-389% multithreaded performance advantage, or 207-412% at 4.6 GHz.

 

[Undying89]

i7 4700QM would be around 4670k performance. Even so i7 4700qm is 2.4-3.4ghz while 4670k is 3.4-3.8ghz. More or less they will perform the same but in singlethreaded applications or even gaming desktop i5 will be somewhat faster.

 

[Sakkura]

Allright! But you're telling me, that there are quad core mobile i7 CPU's out there, which can beat a i5-4670 (example)?

In singlethreaded performance, the fastest laptop CPUs more or less match a Core i5-4670. They will have 20-30% more multithreaded performance because of hyperthreading.

But bear in mind you can get hyperthreading with a Xeon E3 for only slightly more money than a Core i5. And vastly cheaper than anything in laptops.

 

[Casper Traberg-Larsen]

Thank you both! I get i now 🙂 One last question though. I just googled a 4810mq which has amazing performance. It beats desktop i5s pretty good and is not far behind desktop i7's. How long time until there will be a mobile CPU (maybe like 5xxxmq) which will beat a 4790k?

 

[Sakkura]

Probably 2-3 years before something like a 7940MX or 8940MX beats the 4790K.