I'm looking at replacing a 2.5ghz quadcore G5 with a 27" iMac. I am debating between the i5 and the i7 mainly. I am just wondering what how much a performance difference over the G5 there will be, and if the i7 is really worth the extra $. Price isn't a huge issue, but value is. I am leaning towards the i7 as of right now. The computer won't have heavy use, but will occasionally be used with some decent size FCP projects.
Does anyone have any input on the G5 versus the i7?
I'm in a similar position. Here are the things I've been pondering.
Disclaimer: You can easily add bigger HDDs to your G5, and even (if you are so inclined) some nice, fast SSD's. $2000 worth of upgrades to your G5 will make a
big difference to its perceived speed.
Some things to consider:
Storage: Extra HDD space on the iMac will rely upon external disks using FW800, which is considerably slower than SATA-I as used by the G5. The internal drive on the iMac, however, is SATA-II and theoretically much faster than the internal drives in your G5. Internal upgrades to the iMac storage are difficult, and involve removing the glass. Unless a new revision of the iMac comes along with E-SATA, you're going to see a bottleneck.
Memory: I don't know how much RAM you have in your G5, but I have more in mine than the iMac comes with. You get 4Gb from Apple, and I have 6Gb in mine. RAM makes a big difference to the perceived speed of your Mac, and you're better off in many cases getting $200 extra RAM than a $200 speed bump to your processor. That said, $126 spent at OWC will get you an extra 4Gb RAM, making 8Gb in total so it's not the biggest issue, unless you want to put 16Gb in, at which point you'll pay well above $600.
Cores: How often did you get CPU usage above 200% on your Quad? The i5 and i7 have 4 cores each, just like your G5. If you never pushed the G5's capabilities, then along with the increased efficiency of the Intel chips, the i5 will be more than enough. The i7 appears as 8 cores to OS X and will be more use to you if you do 3D rendering or video. It also has a small speed advantage over the i5, but not a huge one.
Screen: That's a nice big screen. It is, however, glossy. If that's an issue for you because you are light sensitive, or doing colour-accurate work, maybe a different Mac would suit you better,and you can bring your own monitor.
Software: How much software do you need to replace when you move forward an OS revision and move to a new processor? For me, Creative Suite is the first thing, and that will add $700 to my purchase price. My 2004 version of MS Office? Another $130 to replace that. Moving to Toast 10? another $80-ish. Essentially, check all the software you need is Snow Leopard
and Intel ready, or you might get bitten.
Peripherals: The same goes for peripherals. That Tiger-compatible scanner may not have new drivers for Snow Leopard and Intel.
Do a little research to be sure, but if you've decided and just want to choose between i5 and i7, Bare Feats recorded the i7 as getting 15-30% better results on average over a bunch of real-life tests. That's got to be worth 10% more cash, because you won't be able to replace the chip later.
Me, I'm hanging on till the revised versions arrive later this year. I'd really like to see E-SATA on the 27" iMac.
