First of all, i am sorry to bring this topic again, but sadly after going through many internet articles and this forum as well, i still cannot find clear answer for my question.

 

I want to upgrade my computer so i have to choose new components.

My computer is to be done as machine made for FSX exclusively.

 

I do not mind "Ivy Bridge", "Haswell" or any other family - finally differences are really minor as i read.

As i have found, right I5 have same 4 cores as I7.

I5 can run overclocked same speed as I7 ( 4.2-5 GHz is not a big problem )

L3 cache amount between I5 and I7 is different by 2MB if that matters ...

 

So my question is : do i really need to buy I7 to have top FSX performance ?

Is it possible that I5 will give same performance as I7 ?

To be clear - we are still talking about FSX only, no other application to be used ( of course apart AS2012, PFPX, RC4, FSReal Time )

 

Appreciate all opinions

Since HT is absolutely useless to FSX, and the main diff between an i5 and i7 is HT and the 2bm CPU L1 cache, I'd say go with the i5 and use the money saved elsewhere, I am going to do so this Fall when I upgrade.

Since HT is absolutely useless to FSX, and the main diff between an i5 and i7 is HT and the 2bm CPU L1 cache, I'd say go with the i5 and use the money saved elsewhere, I am going to do so this Fall when I upgrade.

+1

If you have the budget for it, go for the i7.

 

Sure FSX may not make use of HT, however it will make use of the extra cache. NickN recommends in his FSX Bible thread/Guide (over on the flight1 forum) the use of an i7 for this exact reason.

 

You can also see some results here:

 

http://forum.avsim.net/topic/412162-cpus-compared-clock-for-clock-fsxmarkcpu/

 

Whether you go for an i5 or an i7 I'm sure you'll be happy either way.

 

In your position I would be going for a Haswell i7 4770K, which is exactly what I'm running now.

Budget is not a big issue here, difference between I7 and I5 is around 100 USD.

I want to buy something which will be spot on, no sense to buy things which will give me a bunch of useless assets ...

 

Thx for discussion.

Generally in games, the 2MB of extra cache makes no difference. I have seen claims, but no proof that FSX is any different. In the benchmark linked above, there's no difference between Sandy Bridge and Sandy Bridge-E, despite the -E having more cache.

 

The i5 will allow you to reach higher clock speeds since it doesn't have HT (adds 5-10C in stress tests). You can of course disable HT with the i7, but why pay $100 for something you're going to turn off?

I apologize for hijacking this thread but while we're on the subject I would like to ask, what difference in performance does one expect to see in an OCed i5 vs no OC'ed. I am also looking to upgrade in the coming weeks.

The i5 will allow you to reach higher clock speeds since it doesn't have HT

 

Sorry but that simply just isn't true.

 

Just because it's an i5 and doesn't have HT does not mean it will reach higher clocks. It's a lottery as far as how high you will be able to clock your chip, regardless if whether it's an i5 or i7.

 

I've seen quite a few posts on overclock.net having trouble getting their i5 4670K past 4.2Ghz, where as my 4770K is quite happily chugging away at 4.5Ghz with HT on and others have theirs higher.

 

Don't want to give people the false impression that an i5 will allow higher clocks, because put simply it's incorrect information.

 

I'm not sure if this still holds true, but in the past I've read that the i7's are higher binned chips and for the most part will actually achieve higher clocks.

 

I do however agree that HT can add to your temps and disabling this can in SOME circumstances allow you to clock higher due to reduced temps.

With regards to the FSXmarkCPU test above I'm starting to believe that the IvyBridge i5 result is possible run with the CPU at stockspeed and it will most likely be removed shortly. I'm at the moment analyzing a Haswell i5 result and it looks very much the same as the Haswell i7. So when it comes to FPS in a complex aircraft, an i5 seems to be the same as an i7.

 

To remember tho is that flightsim CAN use HyperThreading to load photoscenery textures quicker. Personally I wouldn't want a quad core without HyperThreading. (that's why I'm using a 6core with HT on and still wish I could have more threads=)

 

Haswell is a large improvement clock for clock vs SandyBridge and IvyBridge, so it's the chip to get if you are building a new system. Even accounting for the lower overclock attainable Haswell is still faster.

 

i5 4670K is very much the best bang for the buck CPU at the moment, but the i7 4770K offers hyperthreading that FSX CAN use for specific purposes, and the SandyBridge-E has another specific use case where its offering better performance over the Haswell i7. But you pay a premium for the i7, and an even greater premium for the Ivy-E. and in the Ivy-E case you actually give up FPS but gain texture loading.

Just a note about HT and o/c:  the only issue with HT enabled when o/c is the increased CPU heat.  On my i7, that equates to about a 20C difference so I leave HT off on my o/c rig.