It has been a long time since I've posted on this board, and probably even longer since I've posted anything worth reading. I was actually just doing some research for college and stumbled onto something that left me wondering. I know that this is an old debate, but it always seemed that the advice coming from this board was: just buy the i5 if you are building a gaming machine (or whatever other apps may apply), because the i7 is getting the bulk of its performance gains via hyperthreading. I started to read this article and this is what made me think of this:
"It's one of the primary reasons that the Core i7 is faster than the Core i5 in some tasks: it has 30% more cache! Hyperthreading may not always be an advantage but having a larger cache is almost always an advantage. I specifically mention this because this advantage of the Core i7 over the Core i5 is often overlooked."
I am just wondering why I generally did not see this mentioned in the past here. I'm sure it was mentioned before here, but generally, the conventional advice usually seemed to be don't even bother wasting the extra money on i7, get the top i5.
But it's still not a big factor. You'll have to first exceed the i5 cache to justify the purchase of 30% more cache. And so in terms of performance, there's no good way to compare them, especially since most of the performance differential depends on the application. It's like buying 16GB of RAM when you won't use up 8GB. Where's the advantage in that? You just wasted money. The i7 is $100 more than its respective i5 here in the USA. So $100 for 30% more cache is a poor validation for purchase if that is the only reason. I'd rather buy something else for $100.
I believe the reason is that modern day CPU's are generally not the bottle necks in systems at the I5 level. Those looking to improve performance will generally see much bigger increases with more and faster RAM, SSDs or graphics cards whereas CPUs are not yet being fully utilized by the majority of applications.
The L1 and L2 caches are identical between the i5 and i7. The i7 has a ~30% larger L3 cache as previously pointed out, which is likely because it is capable of handling more simultaneous processing than the i5 (since it has hyperthreading) and Intel designed it that way. Having a smaller L3 cache does not necessarily make the i5 "slower", in fact, some would argue that making the caches too large would indeed slow down the computer.
Usually what I see around here is that most people don't bother with the i7 unless they have some money to blow that wouldn't really do any good anywhere else. I will say however that for normal daily use an i7 is a better choice. If you're going to be running a lot of programs at once and processing a lot of stuff, the i7 is definitely better and the i5 will bog. But for light use and gaming, you are literally wasting your money with the i7. IMHO Intel screwed up by making the i5 so powerful relative to the i7. When I upgraded from my i7-920 to my i5-4670k system, the difference was astounding. It just goes to show you that single-threaded performance is always the bottom line, justifying the popularity of the i5-4670k right now.
Up until now with the new consoles coming out there was never really a need for the extra cores, while they are only logical cores they will require the extra hardware.
Now with the upcoming consoles there will be a lot of cloud compute going on along with the growing number of physical cores which in the future will be a big part of gaming. Having those extra resources for upcoming games will be a huge plus.
Have we all been paying attention to the recommended requirements for watchdogs and other next gen games for pc?
more cores the better and the i7 will offer a better gaming experience in the not so distant future.
It has more to do with the realistic usage scenarios, sure the CPU might have more cache, hyperthreading or new instructions, but there needs to be software to utilize this advantage.
Right now, this paper advantage is really hard for developers to make use of, that's why currently I5 is a better choice, since it's the same real life performance for more value.
All the advantage of I7 is that if MAYBE in the FUTURE devs will pick their shit up and start utilizing advanced CPU options in a more efficient way, then you are covered. In my opinion - fat chance of that happening, just use logic - most of the gamers don't own I7, so there is no incentive to design with I7 in particular in mind.
People point to new "8 core" consoles as some sort of messiahs for multi-threaded CPU's, but in reality, the new console CPUs are very weak and a decent desktop CPU will simply be able to push through more tasks in the same time, just by the grace of the fact that every task will take a fraction of time to complete compared to console's CraPU.
The only saving grace for I7 here is the fact that if you game AND use additional applications at the same time like streaming such, then you will get more performance, but other than that, not really.