Switching from PC

Discussion in 'iMac' started by xzebra, Feb 20, 2018.

  1. xzebra macrumors newbie

    Feb 20, 2018
    Hello -

    I am looking at the iMac 27 for a new computer switching from PC. My current desktop is PC Windows 7 based. My Lightroom defiantly is starting to go a bit slow with the age of the PC.

    Looking for some advise from current Mac and current LR users on a few subjects:

    1) Is the 27 vs 21.5 inch over kill? When playing with it at BB it tends to have a lot of travel while moving the mouse. Lots of desk real estate needed.

    2) I have heard of LR not working well with the 5k display with some lag at times. Is this old news / has this been corrected or still problematic?

    3) The main question everyone must ask....The Fusion Drive speed. How bad is it??? I love the 1TB drive size and the $300 for 512GB SSD is a lot of extra cash, however reason I love my PC if I was not happy just open up and switch. Not so easy here...hmmmm

    4) iCare for $169 and 3 years of worry free coverage - thoughts??

    5) Any other advise or suggestions for a new Mac user/buyer would be greatly appreciated.

    Thank you all so much for your assistance
  2. anonymous161 macrumors 6502

    Apr 15, 2003
    Where the wind comes sweeping down the plains
    Go for SSD. The cache on the fusion drive is just not big enough to hide the REALLY SLOW spinning disk. Nothing will age the computer faster. Screen size - I've had a 21 for years and it's great. However, if I was buying today I would go for the 27. So much better for the money.
  3. nambuccaheadsau macrumors 68000


    Oct 19, 2007
    Nambucca Heads Australia
    AppleCare+ if you are in the States is essential. No cracking open new iMacs.

    Abandon the 21.5" to its fate. Can't even upgrade the memory so it must come pre-ordered at Apple's prices. 27" user upgradeable with four memory slots.

    Suggest a magic trackpad to go with the Magic Keyboard. No trouble managing a wayward mouse then!

    No matter how much you may be in luuuuv with a 1TB Fusion Drive consider this. It has a mere 32GB of PCI-e Blade Storage, not even enough to store OS X.13 on. The balance goes on the slow old molasses of a 7200 rpm drive.

    Go with SSD.

    This is going to have to last you five years. Awful long time to be unhappy with one's computer.

    If you still need convincing stay with a PC.
  4. OBirder macrumors 6502


    May 13, 2015
    I would recommend the 27 over the 21. For any graphics programs you will enjoy the extra real estate.

    Especially for LR I would highly highly recommend SSD drive. The size should be based on system and applications you load, the LR catalog and especially the Preview Catalog.

    LR speed access to the actual photos is not much relevant. All adjustments are an overlay saved in the catalog and previews.

    The SSD will give you more gain of speed then anything else.

    Otherwise faster processor, more cores, as better. The i7 will be quite a bit faster in rendering than the i5.

    If you buy new, I would add AppleCare, which gives you 3 years worry free.
  5. Fishrrman macrumors P6


    Feb 20, 2009
    Get the 27" model.
    You will NEVER regret having bought it, once you own it.

    DON'T get a 1tb fusion drive.
    Get the 2tb fusion model if you must, but...

    ... you would do much better to spend $100 more and buy the iMac with the 256gb SSD.
    Yes, I realize "it's less storage space".
    But the difference will be one of PERFORMANCE over the life of the computer.
    (the 512gb SSD adds $300 to the buy-in price)

    The SSD is SUPERIOR to the fusion drive in that regard.
    There is no way to understate this.

    If you find yourself needing more storage, get an external USB3 drive and plug it in. Problem solved.

    You CANNOT get an SSD-equipped iMac at BestBuy.
    They MUST be ordered through Apple's "build-to-order" page online.
    A little more time and trouble, but worth the wait.
  6. vkd macrumors 6502a


    Sep 10, 2012
    Yawn, I do get tired of seeing comments like this but I will comment again just to try to help people make educated decisions.

    A Fusion Drive is an SSD + HDD combined in software. The OS sees it as one item and it functions at the speed of the fastest component, the SSD. The speed of the HDD does not affect the overall drive speed.

    Apple designed Fusion Drive technology, it is used on Apple computers. Apple sell it even in the lowest, smallest SSD configurations. It is safe to say that Apple know perfectly well what they are doing. They would not put an SSD that is incapable of fulfilling the design specification. To me this is quite obvious but we see that there are hundreds if not thousands of Apple users out there who think the opposite, that the 32GB SSD + 1TB HDD Fusion Drive will be slow. It will not be slow, it will run at the speed of the SSD. Fusion Drives are an excellent way of having super fast access speeds on high capacity storage at a more affordable price, especially as prices of large SSD, even though they are coming down, are very expensive.
  7. kschendel macrumors 65816

    Dec 9, 2014
    It's fast when you're hitting the SSD. It's slow when the Fusion Drive algorithms guess wrong, or when you rapidly access more data than can fit on the 32 Gb front-side SSD, and you end up accessing the spinner. (It is incorrect to say that Fusion drives always operate at SSD speeds. That only happens when the caching algorithms guess right.) The worst part is that it's extremely difficult to predict when the Fusion will be fast and when it will be slow, and the comparatively small front-side SSD in the 1 Tb Fusion makes it even harder to predict. The 1 Tb Fusion works fine for a wide range of relatively casual usage including what I would call regular "office" work. If you're dealing with thousands of photos in LR I think you are definitely going to want to go all SSD, or at least 2-3 Tb Fusion.

    Contrary to the opinion of some people, just because an algorithm was designed by Apple doesn't make it prescient, and the only way caching algorithms can satisfy 100% of the time is for them to know what you are going to do before you do it. (It's relatively simple to prove this mathematically.) This isn't new. Caching filesystems have been around for decades. Apple's Fusion drives are just a recent iteration, and a pretty good one, but it's impossible to hit the cache (SSD) all the time. Fusion drives have their place, but they're the wrong choice for a lot of more storage intensive workflows.
  8. vkd macrumors 6502a


    Sep 10, 2012
    I find it extremely amusing how some people apply their poor funds of knowledge to things that they have no experience of. No testing whatsoever has been done of the 1TB Fusion Drives by any of these speculators, please be aware of that. So, taking their layman advice, which is pure speculation, as superior to Apple design engineers is a ludicrous idea. Where is any proof of this rationale regarding algorithms tripping out at a certain point? First I've heard of it.

    On the other hand, we have never seen in the history of Fusion Drives ONE SINGLE USER of 1TB Fusion Drive complaining about it. The only ones who complain are those who have never had one and never will have one.
  9. Glmnet1 macrumors 6502a

    Oct 21, 2017
    There are tons of users here that complain that their new iMac with a fusion drive is slow and as soon as they boot from an SSD they're quite happy about the performance.
  10. c0ppo macrumors 65816


    Feb 11, 2013
    Actually, there are a lot of users complaining about FD. And most users on tech forums like these avoid purchasing FD all together. Even Apple released AFPS without support for FD. I guess they forgot their 'magical' algorithms this time :)
  11. kschendel macrumors 65816

    Dec 9, 2014
    This grows tiresome.

    And you know that they have no experience, how?

    And you know that none of the people complaining about FD (and the 1 Tb variant in particular) have actually used it, how?

    I at least am no layman, having 40+ years of software engineering experience in operating systems and database internals. What are your qualifications?

    Surely you jest. The proof is trivial. Here's one: assume a 2017, 1 Tb Fusion (32 Gb front-side SSD). Create 32 1 Gb files. They are written to the SSD (if not, they are written at HDD speeds). Create one more. There's no room on the SSD so it has to write to HDD at HDD speeds. Ok, so let's assume that the FD code flushes the SSD to HDD in the background, making room; in that case instead of creating one more, we read one of the existing files, which is no longer on the SSD, so the read runs at HDD speeds. (If the FD writes the files without clearing them from the SSD we go back to the create-one-more scenario.) There's no way for the FD to always satisfy user I/O requests at SSD speeds, unless it knows ahead of time what the user is going to do.

    Note, I have simplified this example by ignoring the fact that OS/X will likely write to memory first, only flushing to storage when memory is full or during background sync (or on request, etc). That does not invalidate the proof one bit, it just makes doing a real demonstration on a real machine a bit harder due to the extra level of caching (RAM).

    This is blatantly false, pants-on-fire false, unless you assume that all of the many posters on this forum with poor 1 Tb Fusion results are liars. I think it rather more likely that you are just making things up to prove your point.

    By the way, I'll point out that "vkd" has a Fusion with a much larger than standard front-side SSD. It will perform like Apple's 2 or 3 Tb Fusion drives, which are much more likely to give predictable, good results. It's still a caching filesystem, though, and can still be forced to run at HDD speeds by the right sequence of I/O operations.
  12. Jack Burton macrumors 6502a

    Jack Burton

    Feb 27, 2015
    Go all SSD. Everything is faster. Get the biggest SSD you can afford. I splurged on it and went with 1 TB. Now I cannot go back. My former PC with a SATA SSD and 7200rpm media drive feels ancient now.

    I went with a refurb from Apple so I could get Apple care. I saved a few hundred dollars vs new and the refurbs come with 2x the ram direct from Apple (16 instead of 8). They seem to sweeten the deal on refurbs for some reason. I added the another 32 GB for a total of 48. I can swap out the original 2x8 chips for 2x16 down the road if I need to.

    Check out http://refurb-tracker.com and create an alert for yourself when the model you want is available.
  13. xzebra, Feb 21, 2018
    Last edited: Feb 21, 2018

    xzebra thread starter macrumors newbie

    Feb 20, 2018
    Thank you all for taking the time to respond - Much appreciated

    In regards of RAM upgrading, if the Mac comes with 8GB of RAM can I add one strip of 16GB or two 8GB strips or do they all have to match to have similar speed? I have hear that Mac's don't like non-matched RAM quantities?

    Another question I have is referb items. I hear a lot of people recommend them and I have always been a bit leery of the purchase of refurbs. How many here have ordered refurbs from Mac and what has been your experience?

    I was looking at a iMac 4.2Ghz quad core but heard they run really hot - Any truth to this?
  14. Michael Scrip, Feb 21, 2018
    Last edited: Feb 21, 2018

    Michael Scrip macrumors 603

    Mar 4, 2011
    If you go with the 27"... definitely spend the extra $100 for the 256GB SSD. I agree with the others here... SSD or nothing!

    Then save up some more money... and spend $340 on an external 1TB Samsung T5 SSD and keep your Lightroom Catalog and RAW photos on it. (you can get one of those little shelves for the leg of the iMac to hide the drive in back)

    You'd get double the space than Apple offers in that price-range... plus your photos are separate from the main internal SSD. (and it's portable in case you ever want to take your Lightroom catalog and use it with a future laptop)

    I do the same thing with my Windows desktop. I moved all my Lightroom stuff to portable drives... so I can use my actual Lightroom catalogs out in the field. (instead of creating a catalog on my laptop for on-the-road edits... then have to migrate those changes back to my main catalog on my desktop)

    Even if you don't plan on using Lightroom away from your iMac... I still like the idea of keeping that stuff on its own drive.

    And before anyone says it.... yes... the internal SSDs in the iMac are crazy fast.

    BUT... you probably won't notice a difference between the internal SSD and an external SSD over USB 3.0 in Lightroom.

    It'll definitely be faster than a Fusion Drive... :p

    And it's more flexible.
  15. xzebra thread starter macrumors newbie

    Feb 20, 2018

    Really appreciate your assistance.

    Not sure how you specify LR to run the catalog off the USB drive. I have always ran this off the main drive. Could you please help me understand how or what I would need to do this?

    Thank you
  16. aoaaron macrumors 6502

    Sep 4, 2010
    the fact apple still offer the fusion drive is a joke.

    27 inch / ssd /etc.
  17. Michael Scrip, Feb 22, 2018
    Last edited: Feb 22, 2018

    Michael Scrip macrumors 603

    Mar 4, 2011
    I'm glad to help! :D

    There are two basic things in Lightroom:

    - the Catalog file
    - your photos

    The Catalog is simply a database file that references the photos that exist somewhere on a hard drive.

    It is possible to move the Catalog and photos to another drive. You'll have to Google it for the exact procedure... but there are plenty of resources to learn how to move a catalog and photos to another drive.

    I was scared to move my Lightroom Catalog and photos to another drive because I didn't understand how it works. But after some Goolging and watching a few Youtube videos... it was fine. You just have to realize where everything is.

    Once you know where the files are... it all makes sense.

    Your Catalog should be in the "Pictures" folder in Windows. That's probably where your photos are too.

    You'll want to move the Catalog and the photos to another drive.

    I've moved two Catalogs and their photos with no major problems. I already had my photos organized into folders... so I just had to reconnect them in Lightroom once I moved them to the new drive.

    This is how I have my folders set up now:


    As you can see above... I have a folder for the year... then under that a folder for Lightroom (Catalog) and a folder for my photos (sub-folders for each event)

    This way I know where everything is. I know the Catalog is in the same place as the photos that are in that Catalog. It's a nice tidy package.

    NOTE: I always create a folder for each event manually on the drive first and dump my photos from my memory cards into that folder. Then I open Lightroom and use the "Add" import option. That way Lightroom imports the photos into the Catalog but leaves them in the same place. I don't want Lightroom moving my photos since I already have them in the proper folder.

    I, personally, use a different Catalog for each year. It fits my style. And I can access older photos by just opening that year's Catalog file.

    I'm obviously an organizational freak. I like having control of all my files in their proper place. It's nice knowing that the main folder "2018 Photography" has EVERYTHING from 2018 inside it (Catalog and photos)

    You'll probably use a single Catalog. That's fine. But you still need to be aware of where that Catalog file is and where your photos are too.

    Since you're wanting to move from a PC to a new iMac... this is a great time to move your Catalog and photos to an external drive. And then you'll just keep using the external drive for Lightroom.

    And... of course... make sure you have a backup of that external drive. :)

    I hope this helps. Take a look at your files now and see if you can figure out where everything is. Then watch some Lightroom tutorials on Youtube.

    Like I said... I was scared to mess with this because I didn't understand how it all worked. But it's actually not too difficult.
  18. kschendel macrumors 65816

    Dec 9, 2014
    I disagree. There is a place for the Fusion drive when maximum storage for lowest price is needed, with better performance than a straight HDD. That place is not everywhere and it doesn't work well for many use cases. Heavy LR users would seem to be one of them.

    With any sort of luck, SSD prices will drop over the next couple years, and then we won't need spinning rust for anything but specialty usages.
  19. Pangalactic macrumors 6502


    Nov 28, 2016
    I would say get either 27 5k Imac base model or an Imac Pro if you want something powerful.

    The non-5k iMacs are just not worth it my opinion, for around $500 you get a much larger screen with a better resolution and a better GPU.

    Maxing out the 27 5k iMac is also kinda useless, it gets to around $4000k or so, and for a $1000 more you can get the base Imac Pro, which runs circles around the default iMacs with a better processor, miles better GPU, EEC memory starting at 32 gigs an so on.
  20. vkd macrumors 6502a


    Sep 10, 2012
    I would presume that there are deep complications with the new APFS. Case in point, the guy who produces CCC recently posted about sparse file space calculation errors with APFS, procedures that duplicated on HFS+ run perfectly. So not necessarily a problem with FD, which incidentally is command line programming coded specifically for HFS+, so it would have to be completely re-written for APFS.
    --- Post Merged, Feb 22, 2018 ---
    I'd be really happy if you could point me towards them, as all I have seen are tech heads and nerds denouncing them whilst in their sigs we see that they themselves are running big SSDs and so on.
  21. joema2 macrumors 68000


    Sep 3, 2013
    There are lots of users *criticizing" FD who have not done rigorous side-by-side testing with it. That is not complaining, it's uninformed talking.

    I've thoroughly tested my 2013 i7 iMac 27 with 3TB FD vs my 2015 i7 iMac 27 with 1TB SSD, and in most real-world situations there wasn't much difference performance difference attributable to hard drive speed. You can easily contrive a test or look at benchmark numbers but that's not real world usability. In most cases my 2015 SSD iMac didn't boot any faster or start Photoshop any faster or start FCPX any faster than my 2013 iMac with 3TB FD.

    My video editor is editing a 20 terabyte 4k documentary on a 2013 i7 iMac with a 3TB Fusion Drive. It runs just fine and performance is good. In such cases whether the iMac is SSD or FD, most of the data is on an external Thunderbolt array.

    There's a good argument if most of the data is on fast external storage, why not use SSD? No reason why not, and SSD has more consistent performance.

    Then why ever use FD at all? Because there are still fairly common usage scenarios where the user needs more space than, say, 256GB, but they can't afford a 1TB SSD machine and velcroing a portable USB drive behind a 256GB SSD iMac is more complex. In that case they now have two hard drives to back up, which then requires a 3rd hard drive. For that class of user a 3TB FD gives them all the space they'll need for years, good performance and it's a simpler configuration than strapping a portable USB hard drive behind the machine.

    I personally prefer an SSD iMac and all my newer ones are SSD but the 3TB FD iMacs works fine for most real world situations. They can be faster than a bare-bones SSD iMac where most of the user data is on a slow USB portable drive.

    The APFS thing is unrelated to FD. APFS doesn't currently support *any* rotating drive (FD or otherwise) via automatic conversion. You can manually convert a spinning drive to APFS but this is not recommended: https://larryjordan.com/blog/apfs-is-not-yet-ready-for-traditional-hard-drives/
    --- Post Merged, Feb 22, 2018 ---
    It's not that simple. It's technically true a 32GB 1TB 2017 iMac is $3700, and if you count the special deal sometimes available for the base iMac Pro, that's only $4k. In that case the iMP is only $300 more.

    But it doesn't run circles around the top-spec iMac. In some cases such as transcoding 4k H264 video to ProRes in FCPX, the 2017 i7 iMac can be faster, although generally the iMP is somewhat faster. Whether it's *usefully* faster depends on the exact task. The iMP is *quieter* under high load and for many users that's worth $300 or more.

    The OP asked about LightRoom performance. I just tested the latest Lightroom Classic 7.2 on my top-spec 2017 iMac 27 vs my 10-core Vega 64 iMac Pro.

    Time to import and create 1:1 previews for 74 42-megapixel raw stills from a Sony A7R3 was:

    2017 i7 iMac 27: 1:18
    10-core Vega 64 iMac Pro: 00:54

    So for that one test the iMP was usefully faster, but it was 10-core not the base 8-core.

    Re the OP question about whether LR is laggy or slow on 5k iMacs, that's a good question. It definitely has been previously, and LR was so poorly written you could disable GPU acceleration under LR>Preferences>Performance, and it would speed up for certain tasks like using the correction brush. IOW it was faster with the GPU off.

    With the new 7.2 version of LR Classic CC, Adobe has made some significant performance improvements. The correction brush seems more responsive on high-megapixel raw images, and I can't tell any difference in responsiveness between my 2017 iMac and 10-core iMac Pro when *painting* with the correction brush.

    However whether on the iMac or iMP, certain LR actions are still laggy. E.g, paint a region with correction brush, then slide the sharpness slider back and forth. With GPU acceleration enabled that takes three seconds to update the screen on BOTH 2017 iMac OR 10-core Vega 64 iMac Pro.

    If I disable LR GPU acceleration, both 2017 iMac and iMac Pro improve to about 1 second when moving the sharpness slider. So despite the LR 7.2 improvements there are still significant issues with LR performance which no amount of hardware can fix, at least no amount of Apple hardware. On the Windows side maybe you could custom build a cryogenically cooled massively overclocked machine which was fast enough to compensate for Adobe's software.
  22. Glmnet1 macrumors 6502a

    Oct 21, 2017
    The 3TB FD has a lot bigger SSD portion than the 1TB. Usually people complain about the 1TB because they buy it without knowing the it only includes a 32GB SSD.

    While I prefer not having spinning disks at all, I would recommend the 2-3TB FD.
  23. Pangalactic macrumors 6502


    Nov 28, 2016
    That is because it's very badly optimized, surprisingly. Like in the 4k example you mentioned, the CPU/GPU load is something like 30% on the iMac, the multiple cores are not being used to full capability, not even close. So yeah, hopefully Apple will fix this some time soon.
  24. xzebra thread starter macrumors newbie

    Feb 20, 2018

    Thanks a lot Michael for taking the time to detail this out.

    Much appreciated
  25. joema2 macrumors 68000


    Sep 3, 2013
    That particular case is not failure to use cores. Rather the i7 Quick Sync is faster at encode/decode of H264 than AMD's UVD/VCE logic, or at least the way FCPX uses it is faster -- in some cases with some encoding parameters.


    On my iMac when exporting to 4k H264 in FCPX, the CPUs are quit low, yet the same export on Premiere pegs all CPU cores, but is 1/4 the performance. Why? Because software contains myriad "load paths", some visible to monitoring instrumentation and others not so visible. In this case normal monitoring software does not show the Quick Sync hardware is furiously chewing through the data, leaving the CPU cores with less to do -- despite the better performance.

    In the Lightroom case Adobe is doing something highly inefficient when using the GPU. Yet this isn't reflected by low CPU levels. With GPU acceleration enabled, all 10 cores are at about 50% when moving the sharpness slider back and forth on an adjustment brush. With GPU disabled, all 10 cores are at about 10%, but it's 3x faster. Yet another case of lower CPU levels giving better performance.

    They are somehow wastefully burning CPU cycles in *trying* to use the GPU which results in worse performance despite higher CPU activity. When you disable GPU acceleration in LR preferences, it executes the sharpness adjustment using only CPU methods. That may be inefficient judging from the low CPU levels but it's still 3x faster than whatever they are doing wrong in attempting to use the GPU.

    There is setup overhead to copy data from CPU to GPU memory and get it back. If they are doing repeated calls and copying small buffers that can wastefully eat lots of CPU. If they are burning CPU cycles waiting for synchronization in a spinlock (say waiting for the GPU to signal them it's done with a task), this consumes lots of CPU yet doesn't produce anything: https://en.wikipedia.org/wiki/Spinlock

    So while we often equate high multi-core CPU levels with good efficiency, it's more complicated than that.

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