Mac Pro 2.8 (Octa) vs iMac 2.8 i7

Discussion in 'Mac Pro' started by OatmealRocks, Nov 6, 2010.

  1. OatmealRocks macrumors 6502a

    Jul 30, 2009
    Hi. Currently I have an iMac 27 i7 which I love. However I have an opportunity to get a Mac Pro 2.8 Ghz Octa for a pretty good price. I'm wondering if this is worth me switching over?

    One thing is I have an external drive that I use for my data files and getting the mac pro would mean I can add additional drives.

    I guess what it boils down to is how is the i7 chip compare to the 2.8 Octa?

    I do mainly CS5 and LR (photography) and on occasion I do switch into windows to do work. Getting the MacPro would mean I have to buy a comparible size monitor.

  2. firestarter macrumors 603


    Dec 31, 2002
    Green and pleasant land
    I have a 2.8 octa and I have a couple of friends with the i7 iMac.

    The iMac is faster for most tasks that use the CPU. The i7 is a newer generation CPU than the 2.8 octa (which year is this from, last year or Harpertown from Jan 08?).

    Theoretically the Mac Pro could get more work out of each core, as it has 8 proper cores, not the 8 hyperthreaded cores that the i7 has - but the fact is that there isn't much software on the Mac that uses multiple cores well. Lightroom rarely uses even four cores.

    Additionally the i7 can 'turboboost' - that is increase clock speed under load. The 2008 Mac Pro can't.

    My friend and I have tried Handbrake rips on our machines, and his iMac always beats my 08 octa.

    On the other hand, the Mac Pro has 4 drive slots. Direct access to SATA drives internally is a lot faster than accessing an external drive - even if you're using firewire 800.

    A modern 2TB drive might have data read times of say:
    120MB/s internally
    65MB/s FW800
    35MB/s FW400
    25MB/s USB2

    So if you find yourself using a lot of data - then it can be a real advantage having all this local speedy disk space. I have a 10000rpm Western Digital 'raptor' boot drive also - which is a lot quicker than the standard drive shipping in the iMac.

    The bottom line is that I'm glad I have the Pro, since it's definitely fast enough - and will be for another few years - and I really appreciate being able to have four fast disks in there. If I didn't need the disk space, then the i7 iMac would make more sense.
  3. khollister macrumors 6502a


    Feb 1, 2003
    Orlando, FL
    I just went from a 27" 2.66 i5 iMac to a 3.2 quad 2010 Mac Pro, and one of my main uses is photography (CS5, Photo Mechanic and Capture NX2).

    1) The i7 and a Nehalem Xeon Mac Pro processor will be basically equal as far as speed given the same clock. The older Harpertowns are not as the previous poster pointer out.

    2) None of your software will come close to using 8 cores effectively

    3) I went the Mac pro route for RAM capability (32 GB), disk IO bandwidth and flexibility (eSATA, 5 internal drives with the 2nd optical bay, ability to use SSD's, etc), maintainability (replacing drives) as well as a nice little speed bump in my case.

    For a photographer (in fact for most people that aren't running video or rendering jobs or composer running huge numbers of virtual instruments), a faster quad or hex system is a far better starting point. 12-16 GB of RAM, a SSD boot/app drive, a fast HDD for your data/photos and a small SSD for a dedicated scratch/cache drive for CS5 & LR will make a huge difference.

    My 3.2 MP certainly feels faster than my 2.6 i5. Unless you really take advantage of the disk bandwidth and SSD's and or Velociraptor's, a 2.8 octo isn't going to feel much different than a 2.8 i7 iMac. If it is older Harpertown CPU's it will be slower.
  4. OatmealRocks thread starter macrumors 6502a

    Jul 30, 2009
    Thanks for the reply guys.

    I'm not too familiar with the variance in Mac Pro but this model is from 2008 so I suspect it is Harpertown. Harpertown even slower than i7 with same Ghz?

    The MacPro is stock configuration so looks like I would have to buy RAM. Built in wifi and bluetooth right?

    Adding SSD is what I want to do. Debating on getting 64 GB (OS X) only but another SSD for the scratch disk is a great idea. I was not aware of faster transfer speeds when the drives are mounted internally. I want expandability so all your suggestions are great.

    Going to look at the computer tomorrow. If everything is good I'll most likely jump **** and have to deal with selling the iMac and start looking for ram modules, HDs and a new monitor.
  5. Einz macrumors regular


    Feb 14, 2008
    It's the interface, externals (esata) can be as fast as the internals. FW and USB2 are just slower.
  6. firestarter, Nov 7, 2010
    Last edited: Nov 7, 2010

    firestarter macrumors 603


    Dec 31, 2002
    Green and pleasant land
    Yes. I'm not sure 'even slower' is the right phrase. They're both darn fast!

    No. Neither bluetooth or WiFi. I've never added WiFi - I used a wired connection. I added a generic 'no brand' USB bluetooth for £10 and that works fine.

    You might want to avoid the Apple monitors. That's one real advantage the Pro has - you don't have to have one of Apple's silly shiny screens, and can have a matt one more suited to editing photos. Make sure you get an IPS screen.

    I'm not sure that I would do this if I were you. Consider that you're moving from a fairly new machine to one with up to three years of wear also. As an alternative - have you looked at the latest model of the 27inch iMac - it can take both SSD and a regular drive.
  7. cluthz macrumors 68040


    Jun 15, 2004
    Getting a replacement screen for you iMac will cost you about $900 alone, unless you are willing to downgrade.

    The 2.8 octo is a great machine, but there are some issues:

    1) It came with 320/500GB stock HD. iMac HD is faster and larger.
    2) Ati 2600 graphics (or optional nvidia 8800), the 4850 in the iMac is four times faster than the 2600 and quite a bit faster than the 8800.
    3) Photoshop doesn't really scale well beyond 4 cores, thus the i7 will be faster, but only slightly.

  8. khollister macrumors 6502a


    Feb 1, 2003
    Orlando, FL
    Bluetooth and wifi weren't built in until 2010 I believe. The internal drives are faster than FW or USB, but a $50 eSATA PCIe card gives you 2 external ports that are just as fast.

    BTW, what are you paying for this thing?
  9. OatmealRocks thread starter macrumors 6502a

    Jul 30, 2009

    that's the one concern. Moving from new computer to a used one. However the expandability is great but at the same time it takes quite a bit of room. Which the low factor iMac is great. I don't think I will have an issue selling my iMac or upgrading SSD but upgrading SSD is probably best on the MacPro.

    I will have to get BlueTooth and Wifi but that seems like an easy fix.

    Cluthz.. Not worried about the graphics card but will buy if necessary. I rarely play games and it would mainly be used for CS5 & LR. You are right about the screen. Im debating on getting trying to find a older cinema 30" or buying a 27+ IPS screen from Dell or something..

    khollister ARound $1500 deal?
  10. khollister macrumors 6502a


    Feb 1, 2003
    Orlando, FL
    If you were a musician, I would say do it because most of the music SW doesn't handle hyper threading well. However, as a photographer, you are giving up most everything for disk IO (which is important, but...)

    I'm just not feeling it, even if it turns out to be an even swap (although you are still out the cost of a monitor).

    I really think you want a 2009 0r later MP at this point. And 8 cores is useless for PS and LR at this point.

    I would actually suggest spending some money to increase the memory in your iMac to 16GB ($320 at OWC - helps CS5 from hitting scratch), and getting additional FW 800 drives if you need them for backup, etc. I went from a 2.6 i5 to a 3.2
    Xeon (i7 for all intents and purposes in this discussion) plus SSD and there is a definite improvement. You are not going to be as happy - the i7 is a faster CPU than what you are going to and the cores won't help you much if at all. The only performance improvement will be the ability to get a faster boot and scratch drive. 16GB RAM in the iMac will help avoid the scratch for CS5.

    My recommendation is take a pass and save for a current (or later) MP so it is a clear step up for you.
  11. gpzjock macrumors 6502a

    May 4, 2009
    27" iMac FTW

    I have a 2008 Mac Pro 2.8 octo which I have upgraded over time since buying it new, with 16 GB RAM, 2.4 TB in storage HDDs, a 5870 1 GB card and a SSD for the system drive it returns an Xbench score of around 300.
    Originally with 10 GB RAM a 320 GB HDD and a 8800GT 512 MB card it ran scores around 200.
    If you have a decent Xbench result on your iMac by comparison I would stick with the i7.
    The gorgeous 27" screen is worth any lack of internal expansion in my opinion and its modern chip architecture is superior to the Harpertown server chips from 2 years ago.
    I say save your dosh for a newer Pro in a couple of years time. :D
  12. OatmealRocks thread starter macrumors 6502a

    Jul 30, 2009
    gpzjock & khollister.. 27 iMac screen is beautiful.. you right. I have 4TB external via Firewire. I think I may invest in a SSD instead and perhaps ram in the future. When I am using CS, I only have a few other programs open. It appears my current 8GB is doing well (i think).

    Perhaps I should wait in a year and try to find a Mac Pro that is one model more current. Really can't complain on the iMac now.

    Thanks for your help.

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