Haswell rMBP i5 13" for hammering virtual machines?

Discussion in 'MacBook Pro' started by mrmors, Oct 25, 2013.

  1. mrmors macrumors member

    Joined:
    Jul 29, 2011
    #1
    Hi, I currently have a 2011 MBA with a i5 1.7, and 4gb, 256gb ssd.

    When I bought it, I didn't really intend it for using VM's/Parallels too heavily even though I did install a couple of VM's.

    My usage pattern has now changed for work, and I quite heavily or need to use VM's, and ideally I need to run 2 at a time, probably a 2008 server and some sort of poxy windows client to communicate with it.

    I currently have a 2008 server VM on there with 2gb ram assigned, and 1 or 2 processors, and it runs fine, until I have to start hammering it a bit, then it runs like a dog, starts making my host OSX machine lock up, runs that hot I can cook breakfast off the top left hand corner of the machine, whilst it's fans are running that hard that they'd probably blow the curtains.

    So I know need more memory, but I'm wondering whether I need a new Haswell MBA or a new Haswell MBP?

    Is there going to be any difference really between them for this sort of usage if I spec them out with 8gb of memory? I know I'd probably be better off with 16gb memory, and in that case my hands are tied I'd have to get a MBP. But say I went down the 8gb route, would the MBA be adequate? I'm planning on getting the 13" version, and i5 not i7.


    Are any of you using your MBA or MBP for VM's, possibly 2 at a time, and hammering them? How do they cope?

    In an ideal world, I want a new machine, that I can install 2 VM's on, hammer them, and the laptop not to set fire to my leg if it's on my lap and I don't want the neighbours knowing the fans are on as they're running that hard. Is this possible?



    Thanks for any advice
     
  2. robvas macrumors 68020

    Joined:
    Mar 29, 2009
    Location:
    USA
    #2
    Running 2GB VM with just 4GB of RAM is a recipe for a slow machine. 8GB should be plenty. You should only assign 1 vCPU to your VM as well.

    You want to have a fast disk (SSD) and lots of RAM (8GB) to have a good time running VM's. Especially more than one. I use a 512MB XP VM on my 4GB machine and sometimes fire up a 1GB Linux VM.
     
  3. mrmors thread starter macrumors member

    Joined:
    Jul 29, 2011
    #3
    Hi Robvas, yes, I know my current solution isn't ideal, I never really thought I'd be running VM's on there needing 2gb+ of memory.

    The way I run one of the VM's, it takes the virtual processor usage upto 100% and takes all the RAM I've assigned to it, so it starts cooking.

    I'm wondering whether the rMBP or the MBA will be best suited to my needs.

    Is there going to be any real difference getting a rMBP over the MBA if the memory and disks are the same? Would the chip make a difference? People have mentioned better I/O?

    You mentioned assigning 1 vCPU per VM, so does this mean I could only run a maximum of 3 VM's at any 1 time due to using an i5?
     
  4. magbarn macrumors 68000

    Joined:
    Oct 25, 2008
    #4
    The rMBP 13 isn't that much faster than a MBA when running vms other than the ram difference. If you need to dedicate more cores for your vms, then the only big upgrade for you would be the rMBP 15. A refurb 2012 rMBP 15 right now can sometimes be found around $1599. That's an excellent deal for 2.3/8gb/256. The Haswell version isn't much of an upgrade CPU wise and the lack of the dgpu is actually a downgrade.
     
  5. AlecMyrddyn macrumors 6502

    Joined:
    Dec 5, 2008
    Location:
    Southern Maine
    #5
    Take a look at geekbench scores for your intended builds.

    The current MBA 1.7 i7 is about 14% faster than your 2011 1.7 i5

    Comparing the processors of the Haswell MBA 1.7 i7 vs. rMBP 2.6 i5 the MBA is actually faster for single core tasks, and the 2.6 i5 rMBP is only about 5% faster than the MBA for multicore tasks. So if you are CPU bound and not memory bound, you may not notice a difference between the two.

    The real issue is that both the 13" rMBP and MBA are running dual core processors. They both support Hyperthreading so each core appears as 2, giving you a total of 4 virtual cores. But if you have two VMs, each trying to maximize their CPU usage, you are going to start feeling it.

    What does your memory & CPU usage in Activity Monitor look like with both VMs running when you are noticing the slowdowns? That can help determine if you are having RAM/swap issues, or if you are hitting CPU limits, or both.

    If RAM, then either the new MBA or 13" rMBP with 8GB should help. If it's CPU, since they are so close in speed, you'd probably be better off looking at a 15" as they are true quad-core processors. You could probably get a good deal on a refurb Ivy Bridge 15" rMBP right now is price is a concern.
     
  6. robvas macrumors 68020

    Joined:
    Mar 29, 2009
    Location:
    USA
    #6
    You can run more than three - they'll share the CPU if they are all trying to do something at the same time.
     
  7. miamiboyca macrumors newbie

    Joined:
    Sep 18, 2012
    #7
    I am currently running a Win8 VM using fusion with a Haswell MBA, i7, 8GB - with 4GB/1 Core assigned to each machine While it does work ok, but its not great and frankly I don't hammer it. I tend to run project/visio and other office apps on the VM. I am looking at upgrading yet again - and I would suggest going to a 16GB MBP, whether the 13 or the 15. I am right now looking at doing the same thing. Just put my MBA on ebay to see what I can get for it so I can use the difference to upgrade.

    Really wish Apple would have given the quad core as an option on the 13 as I prefer the portability :(
     
  8. AlecMyrddyn macrumors 6502

    Joined:
    Dec 5, 2008
    Location:
    Southern Maine
    #8
    Me too, but the lowest power Haswell Quad Core Intel makes has a TDP of 45 watts, and it only comes with an HD 4600 iGPU. Everything with the Iris Pro iGPU is 65 watts or more...

    In comparison, the Ivy Bridge 13" rMBP used 35 watt processors, the new Haswell 13" rMBP uses 28 watt processors.

    Meaning, there is no way the 13" has enough battery or cooling capacity to support a quad core.

    As much as I would love one as well, I think Apple's Engineers made the right call.

    If Intel can ever release a quad-core with lower TDP & perhaps Iris Pro... well, then Apple might be able to use it in the 13".
     
  9. mrmors thread starter macrumors member

    Joined:
    Jul 29, 2011
    #9
    Hi Alec, regards to your first link, that seems to be showing on geekbench that the new MBA is about 40% quicker than mine based on the geekbench score? 2150->2974?

    Regards to that second link that's comparing a MBP i5 vs a MBA i7?

    When I'm getting the slowdown, I'm hitting 100% on both CPU and memory, I don't know if this would change if I had the ability to assign more memory?

    I don't want to be in a position where I buy a MBA or rMBP, assign more memory and end up no better off really as I hammer the new processor aswell, and the additional memory doesn't really make a difference.

    To be fair, it's only when I run one particular app that the CPU and memory get hammered, normally it's fairly acceptable if I'm not running it.

    The 15" isn't really an option for me as I really like the portability of the 13" and the cost starts ramping up with the 15", even on a refurb.


    Thanks a lot for your input so far guys
     
  10. AlecMyrddyn macrumors 6502

    Joined:
    Dec 5, 2008
    Location:
    Southern Maine
    #10
    Correct, about a 40% increase from the 2011 MBA to Haswell MBA with 1.7 i7.

    Correct, the 2.6 i5 in the 13" Hasewll rMBP and 1.7 i7 in the Haswell MBA are roughly equivilant.

    Can you share screenshots of both tabs in Activity Monitor when you are hammering the system and it feels slow?

    What does the Task Manager Performance Tab / Resource Monitor (assuming Windows) in the VM look like? It might also help to be able to allocate more virtual RAM to the VM... You only have 2GB allocated now? The heavy process may be swapping inside the VM just as OS X is swapping as well, this will double the amount of access to the SSD and slow things down even more.

    Additional memory will help to some extent, because you won't be swapping active memory to the SSD and back. The SSD is probably around 20 times slower than RAM, and the act of stopping to move data from RAM to SSD and back adds more waiting time before work can begin again.

    Obviously an upgrade from the 2011 to a Haswell system will help too, given that the newer systems are roughly 40% faster.

    The Haswell systems have the new PCIe SSD which is 40% faster too. So anything that does need to access the SSD will get done quicker.

    If I were in your situation, and I had the budget, I'd opt for the 13" Haswell rMBP with at least 8GB and the 2.8 GHz i7. It might be worth getting the 16 GB RAM upgrade as well, but I'd have to see your RAM usage within the VM and OS X to make a better guess. Both of these upgrades put the rMBP a little ahead of the MBA in performance.

    If you don't have the budget, the 2.6 i5 and 8GM of RAM should definitely help, the question is will it be enough...?

    Depending on what amount of storage you get, the i7 and 16 GB does start pushing the 13" rMBP into the same price range as the 15".

    If you don't use this particular application in the VM that frequently...
     
  11. mrmors thread starter macrumors member

    Joined:
    Jul 29, 2011
    #11
    I'm thinking maybe the i5 2.6ghz rMBP with 16gb, I'm not sure what extra a dual core i7 would give? I understand a quadcore i7 obviously giving me 8 virtual cores, but with the dual core i5's and i7's I'd have thought I'm really only making a difference on the clock speed front really, and marginal?

    If only I could put 16gb in the MBA lol
     
  12. AlecMyrddyn macrumors 6502

    Joined:
    Dec 5, 2008
    Location:
    Southern Maine
    #12
    According to current Geekbanch averages, the 2.8 i7 compared to the 2.6 i5 gains you between 2-5%. Other than the clock speed difference, the i7 has a larger L3 cache of 4MB compared to the 3MB on the i5. Everything else is the same.

    In my opinion it's probably not worth it to spend the $200 to go to the i7 on the 13" rMBP. unless you know you are severely CPU bound and that extra few percent will be noticeable, or you want to eek out every last year of service you can from the machine...
     

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