iMac Late 2015 5K 27" 3.2 GHz, 32 GB RAM, Radeon 290 2 GB value?

Discussion in 'iMac' started by CheesePuff, Jul 10, 2019.

  1. CheesePuff macrumors 6502a

    Joined:
    Sep 3, 2008
    Location:
    Southwest Florida, USA
    #1
    Can pick one up today in great condition and with original Magic Mouse and keyboard and box for $900 USD - worth it? Upgraded 32 GB RAM, but has the lowest 3.2 GHz i5 and 1 TB 7200 RPM drive (would use an external USB 3.0 SSD for the boot drive).
     
  2. CheesePuff thread starter macrumors 6502a

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    Sep 3, 2008
    Location:
    Southwest Florida, USA
    #2
    Picked it up for $850, well worth it. Excellent condition. Will be using a USB 3.0 external SSD drive as the boot drive, since this models 1 TB fusion is only 24 GB SSD.
     
  3. mikehalloran macrumors 65816

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    The Sillie Con Valley
    #3
    Give it a really nice speed bump with a 970 EVO. The blade is about 4x faster than the ACHI blade that Apple used as part of the FD and 6x faster than booting from the SATA III SSD in your external.
    https://www.amazon.com/Samsung-970-EVO-2TB-MZ-V7E2T0BW/dp/B07BN217QG/ref=sr_1_2?crid=L5WBZVVEACRY&keywords=970+evo+2tb&qid=1562802873&s=electronics&sprefix=970+evo,electronics,196&sr=1-2&th=1

    There are slower, less expensive NVMe 3 x4 blades such as the 660p but I wouldn't install them in a 2015 iMac. Unlike the 2013–14, this has a PCIe 3 x4 bus and can handle the full speed of the 970.

    No hurries, it's something you can always do. You can remove the SSD from that external housing and install it in place of that HDD if you need additional space.

    Besides the blade, you need the Sintech short adapter ($15) and it's a good idea to replace the NV RAM battery as long as you're in there with a CR2032 medical battery (if keeping the HDD, use a high-heat resistant BR2032 as Apple does). It's a little soon for these (5 years is the recommendation) to be going bad but, as long as you're in there...

    Labor averages $75 from most techs in the Silicon Valley. There are a few necessary tools and an $11 tape kit if you want to do itself.

    When done you'll have an iMac nearly as fast as a 2017 but with TB2 ports. Well worth it and you will absolutely notice the difference in a 2015 no matter what your uses. It will run cooler, too.
     
  4. CheesePuff thread starter macrumors 6502a

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    Sep 3, 2008
    Location:
    Southwest Florida, USA
    #4
    I don't know of any shops in SW Florida that would do this (or that I would trust), and I definitely don't want to try it myself opening her up (even though its out of warranty). I do wish it had Thunderbolt 3 ports, but at least for what I'm using it for, USB 3.0 speeds on a Samsung T5 for instance will be plenty and much better then the internal.
     
  5. mikehalloran macrumors 65816

    Joined:
    Oct 14, 2018
    Location:
    The Sillie Con Valley
    #5
    Says you.

    No Apple techs in South Florida? Actually, a couple of the biggest ones in the country are located there. This is an easy-in/easy out modification. Make an appointment t drop it off, go to lunch and pick it up. Takes me a half hour but only because I’m one-handed (really). A number of Youtube videos, too. Only look at the ones that use what looks like a plastic pizza wheel to separate the screen. Ignore the ones that use a heat gun or guitar picks.
     
  6. Ledgem macrumors 68000

    Ledgem

    Joined:
    Jan 18, 2008
    Location:
    Hawaii, USA
    #6
    I have a Late 2015 27" iMac, almost fully upgraded (512 GB SSD instead of 1 TB) - it's a very nice system that still has a lot of life left in it, and the display is beautiful. Lack of Thunderbolt 3 is kind of a let-down, though, as there are a lot of neat things you can do with it these days. I would have hoped that Thunderbolt 3 would have bottomed out the prices of Thunderbolt 2 peripherals, but it hasn't - they've just become more rare. Seems kind of silly to buy full-price Thunderbolt 2 stuff that won't be able to be carried over.

    For ensuring that the life of the system could be extended a bit further I would have suggested not getting this system, and holding out for an iMac that has Thunderbolt 3 ports. But you have it, and I think it was a good deal, so enjoy!
     
  7. Sensamic macrumors 68030

    Joined:
    Mar 26, 2010
    #7
    Why is Thunderbolt 3 so important for extending the life of the iMac?

    I've got the 2019 model but I'm curious.
     
  8. Ledgem macrumors 68000

    Ledgem

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    Hawaii, USA
    #8
    Thunderbolt 3, similar to Thunderbolt 2, allows you to connect devices as if they're connected directly to the motherboard. However, the increased speed means that these components can sometimes now outperform the speed of components natively installed.

    The two big examples right now are in storage with SSDs, and with external GPUs. The SSD can be upgraded in some models of iMac (I'm not sure about the latest ones), but it requires dismantling the computer and is pretty tricky. The GPUs can't.

    As an example of what I'd use it for, I do heavy photo editing and some video editing. My photo library is pretty large, and I "only" have the 512 GB SSD in my iMac. The latest SSDs are not only faster than the one in my iMac, but suppose I were going to upgrade my iMac now: getting one of larger capacity external SSDs would be cheaper than if I had wanted to upgrade through Apple. In my case, I'd just like to run my photo library off of the SSD for a speed boost... but people are also using these external, Thunderbolt 3-connected drives as their boot drives for a speed boost.

    The external GPU also comes into play. Even though I upgraded the GPU on my iMac (2015), the latest ones run circles around it. And while connecting through Thunderbolt 3 offers a 10-15% performance reduction compared with having the GPU installed directly to the motherboard (which isn't an option for us, anyway), some of these cards are already offering double or more the performance of my graphics chip... and this system is barely four years old!

    Coming from a 2019 system, what I've mentioned may not offer as much benefit to you. Yet it's easy to see that the pace of technology means that our systems are outdated pretty quickly. I'm stuck with Thunderbolt 2 ports, but the 2017 iMacs have Thunderbolt 3 chips and would be able to make use of those benefits. While unproven right now, it's also possible that if your GPU failed you might be able to continue using your system with an external GPU, instead of requiring an expensive repair or having to junk the entire system.

    Oh, and one final, nice benefit of Thunderbolt 3 peripherals: you'd be able to take them with you to your next system. So if you opt for a 1 TB SSD, it's not like our iMacs, where you kiss it goodbye when you upgrade. Maybe it would no longer be the fastest SSD around when you reach the point of thinking to replace it, but you could still utilize it.

    Presumably Thunderbolt 4 (whenever it comes around) will retain backwards-compatibility with Thunderbolt 3, just as TB 3 did with TB 2. So the devices you buy now would still be usable, too.
     
  9. Sensamic macrumors 68030

    Joined:
    Mar 26, 2010
    #9
    Wow great explanation thank you!

    The GPU thing is very interesting indeed. Could any GPU in the future be used that way with a TB3 enclosure? Or is there compatibility requirements? How do you tell MacOS to use the external GPU instead of the internal one if you have one connected?

    I come from a late 2009 iMac. I used an external SSD through FireWire as my boot system, and now I've reused the SSD buying a new USB 3 enclosure for it, so it's nice being able to extend its life even more. It's 10 years old also.

    Can't seem to find external TB3 enclosures to install an SSD one for itself.
     
  10. Ledgem macrumors 68000

    Ledgem

    Joined:
    Jan 18, 2008
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    Hawaii, USA
    #10
    In theory, yes. Right now it seems Apple only supports AMD graphics chips, and even then, only certain models. It remains to be seen if they keep expanding their graphics card support, but it's very likely that they'll continue to add support for at least some new models moving forward. They've been making eGPU usage more seamless and friendly over the past 1-2 versions of macOS, so it does seem to be a priority for them.

    Many users report that the eGPU is used seamlessly. You can force a program to use it through an option in the information panel, but that option seems to only show if you have an eGPU.

    There's a user thread on eGPUs that you might find interesting to peruse, and that might give some sense about how people are using eGPUs and what their experiences are like. eGPU support has come a long way, it seems very usable right now, and it's likely only going to keep getting better.

    I'd guess that your SSD is a 2.5" drive using a SATA III interface. I'd imagine that there are some enclosures that you could use, but USB 3 should be fine; SATA III has a theoretical maximum burst speed of 6 Gbps, while the USB 3 ports on your 2019 iMac support 10 Gbps. (Thunderbolt 3 does 40 Gbps.)

    But modern SSDs don't use SATA, and instead use NVMe. SATA-based SSDs tend to have speeds in the 500 MB/s range, whereas NVMe SSDs are usually in the thousands (up to 3,000-some MB/s). Huge difference, and an example of where Thunderbolt shows its utility. Granted, it's no reason to dump your current SSD, but it goes to show that even SSDs have experienced tremendous development benefits over the past few years. Thunderbolt 3 will allow you to keep pace more easily.
     

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9 July 10, 2019