2011 iMac VS 2012 Macbook Pro (Non-Retina)

[godzillinois]

Forgive me for my ignorance, but I had some questions about Quad-Core VS Dual-Core and Geekbench Scores.

So I currently own a 2012 13" Macbook Pro and am looking to add a desktop as well, but one that is 'faster' than my laptop. If I understand correctly, having double the amount of cores should theoretically make a computer twice as fast as one with a similar chip/processor? Yet when I compare the iMac I want to my Macbook the Geekbench scores are faster, but not anywhere near twice as fast. Am I missing something? Does having a previous generation Intel i5 chip make that much of a difference even with double the cores? (please ignore the 3rd Mac listed in the screenshot below, Everymac lets you compare 3 different Macs and it's just the default.)

I want to have a desktop that's much faster than my Macbook Pro, does that mean I at least have to get one with the same year/processor for the quad-core to show that much difference than the dual-core?

 

[smallcoffee]

Double the cores does not necessarily mean double the speed.

What is your use case? What do you do with your Mac? What is your budget? Why buy a really old computer?

 

[smbu2000]

In this case I think that the scores are also influenced by the presence of Hyper-threading as well as the IPC improvements of the IB cpu in the 2012 mbp compared to the SB cpu in the 2011 imac.

The 2011 imac cpu has 4 cores and no hyper-threading.

The 2012 mbp cpu only has 2 cores, but hyper-threading gives it a total of 4 threads and while the HT is not as good as having 4 real cores it does help especially on synthetic benchmarks. The newer Ivy Bridge cpu also gives roughly 10% better performance at the same clock speed as the Sandy Bridge cpu in the 2011 model helping to bridge the gap.

I'm not sure how much of a performance boost you will get from the older system compared to your 2012 mbp. If it had an i7 (4 cores with HT) then the difference would probably be more significant.

I'm currently using a late 2011 15" mbp, in clamshell mode connected to 24" monitor, and although it has a lower clocked 2.2ghz (turbo to 3.1) SB quad core i7 with HT the Geekbench 3 MC 64 score for it is 9423 compared to the 5689 of your 2012 mbp and the 7237 of the higher clocked iMac.

 

[kschendel]

If only it were as simple as cores and base Ghz! At the CPU level, you also need to consider:
- max turbo clock if any
- heat disposal capability of the system (excess heat -> thermal throttling)
- cores vs hyperthreads
- application ability to use multi cores vs single threaded "straight line" code
- instructions per clock
- cache and cache effectiveness
and that's just the obvious stuff.

I trust your choice of 2011 iMac was just for pedagogical purposes? because IMHO that machine is in a bit of a tight spot, given that it has Thunderbolt 1 (rare and expensive periperals) and USB 2 instead of 3 (slow). Just for myself, if I were buying retro, I'd either go older like an early 2009 which would be cheap and is easy to get into for internal SSD (even if SATA II), or newer, at least late 2012 which brought in USB 3 and the possibility of reasonable speed external SSD. Note that I don't necessarily recommend either, but the 2011 iMac is best lovable if you already own one.