2.7 (i5) vs. 2.8 (i7)

[chris1987]

Been lurking for a good few months since deciding i wanted an iMac back in March (i guess everyone has been) and thought i'd finally get involved in the forum!

Quick question - first of many no doubt. Is the performance boost of the CPU's in the title substantially different? I know it's for the current iMacs but it's a good guess that the spec jumps will be of an equivalent (relative) amount with the new iMacs. Seems £160 is a little steep for a 0.1GHz increase, guessing it's the i5/i7 change that is the difference. Would it be a blatantly noticeable upgrade? Is it worth it? Would i be better off investing £160 in upgrading RAM instead? Also, does replacing the RAM void the warranty (assuming the new RAM isn't soldered)?

Been slugging away on my Macbook Polycarbonate since 2008.. it can't handle Xcode, Firefox, Skype and Photoshop at once anymore.. really can't wait to get a decent machine.

Hopefully in 34 hours time this forum will be buzzing with excitement!

 

[richest]

Replacing Ram is fine, Apple allow it and class it as user upgrade able. Provided you use the correct type and choose a decent brand such as crucial.

 

[cyclotron451]

Hi, there was an excellent resumé of the processors in this article https://forums.macrumors.com/threads/1146818/ otherwise Anandtech is your friend!

I had personally ordered the 27" iMac Quad i5 2.7 (based on the brilliant Turbo Boost figure) but until we see what tomorrow excatly brings I'm not sure what my favourite choice will be. I might still get a Mac Mini + big screen.

RAM is just about the only part that IS considered user upgradeable by Apple. A slight quirk about the RAM & warranty is that in the past machines have been refused a diagnosis/repair because it contains non-apple supplied RAM. This is simply solved by buying new RAM from anyone except Apple, but if your machine needs a repair then put your original sticks back-in. On the past & current iMacs it is a very simple to get access to the SODIMMs - single screw - under the chin to remove, you'll need a high quality (not made of cheese) screwdriver - philips size 0.

 

[Thessman]

The i7 2600S 2.8 differs from the i7 2500S in only three things, apart from the measly 100MHz (~4%) that is. The 2600S has 2 more MB's of level 3 cache for a total of 8MB instead of 6 for the 2500S, the second thing being a faster clock for the on-chip graphics (Intel® HD Graphics 2000), max clock 1.35 GHz instead of 1.1 GHz for the 2500S.
Probably the most significant difference is that the 2600S supports hyper threading, which will give you about 5% to 15% more processing power depending on the app, when you have all your cores full.
You are probably better off with more ram...

 

[chris1987]

Hi, there was an excellent resumé of the processors in this article https://forums.macrumors.com/threads/1146818/ otherwise Anandtech is your friend!

I had personally ordered the 27" iMac Quad i5 2.7 (based on the brilliant Turbo Boost figure) but until we see what tomorrow excatly brings I'm not sure what my favourite choice will be. I might still get a Mac Mini + big screen.

RAM is just about the only part that IS considered user upgradeable by Apple. A slight quirk about the RAM & warranty is that in the past machines have been refused a diagnosis/repair because it contains non-apple supplied RAM. This is simply solved by buying new RAM from anyone except Apple, but if your machine needs a repair then put your original sticks back-in. On the past & current iMacs it is a very simple to get access to the SODIMMs - single screw - under the chin to remove, you'll need a high quality (not made of cheese) screwdriver - philips size 0.

Cheers for the link.

The performance boost seems pretty significant judging by those benchmarks.. upgrading from a 2.7 i5 - the 0.1GHz i7 boost is more noticeable than a upgrading a 2.7GHz i5 to a 3.1GHz i5.

I take it that Apple haven't implemented any 'flags' that tell if the user has upgraded the RAM then? Whether it's a software flag or some tape in the iMac itself for example.

 

[One Still Sheep]

i7 processors have hyper-threading while i5 processors do not. Depending on the software in use this could prove more important than clock speed numbers.