Computer Advice

[Black Pearl]

I'm about to bite the bullet and replace my five and a half year old iMac with a newer 27" 5k model.

There are a few configurations I can fiddle with and more to the point afford but I don't know where to spend the cash for the biggest gains. It will be used (other than general web browsing and day-to-day stuff) for Lightroom and Photoshop. I don't play games - AT ALL - and I don't really do any video other than a few daft bits from the iPhone.

Best value: Skylake i5 3.2/3.6 - 256GB SSD - M380 2GB GPU - 24GB RAM *
Middle value: Skylake i5 3.2/3.6 - 256GB SSD - M390 2GB GPU - 24MB RAM *

Not sure if there is any real world gain in the AMD RADEON M390 over the M380?

I can pay a bit more and go with a Skylake 3.3/3.9 i5 processor and either the 256 SSD or a 2TB Fusion Drive that includes 128GB of flash memory that the OS uses to optimise the system. Not sure the small (I think) processor speed boost is worth the extra cash but this model has a M395 2GB GPU that might give it a little more speed when rendering and exporting - again I'm not sure as a web search only mentions its gaming performance gains. To this model I can pay an extra £200 for either a Skylake i7 4/4.2 processor - or - a M395x 4GB GPU. Can't afford both those so would the i7 processor or the 4GB of VRAM be better for LR and PS? Or I could stay with the i5/2GB option and spend £200 on a Thunderbolt external drive instead of the USB3 drive I currently have all my LR library on which might speed up the loading times for the library and import/export of images.

Any advice would be greatly appreciated - but - please don't make this a PC v Mac thing as that simply isn't an option.


* I'll be adding the extra RAM myself as its cheaper to buy third party and dead easy to install.

[billtils]

Robin

I can't help with anything specific as I have a MacBook Pro with external monitor, and don't use LR or PS, but, for what it's worth, I have a photo buddy who is a retired software engineer and his experience may ease your concerns. He had a similar configuration to mine but wanted to recycle his MBP into the family user-pool. He eventually settled on a Mac Mini with max RAM and SSD. He was concerned that the current version is very restrictive on CPU options but made the leap. His experience is that for his regular processing the Mini is just as fast as the MBP was despite the CPU "downgrade".

I would seriously consider the Thunderbolt upgrade though, having used both it and USB3.

[Shanghai Steve]

Hi there
From a quick look online, the most important thing to find out is wheher the 380 is an R7 or R9 380 as there is a significant difference in capability between them. TBH, it looks like neither of them are particularly brilliant, although the 390 is a bit better than the NVidia GTX 960M, which these days is kind of lowest acceptable GPU for dedicated gaming. Remember the 390 uses DDR5.
I do not play games either, but that's a bit like saying I'm not a professional Rally driver: modern-day gaming is extremely hard on computers and even a machine with a top-spec Skylake i7, NVidia GTX 980 and 32GB of 2133 MHz DDR5 RAM finds it's limits when set against the most processing-intensive games at the highest resolutions. Of course, at this point, thermal throttling is a major issue. So gaming tests are above the stresses that even DXO Optics Uber-special noise reduction imposes on a machine.

So if it's a choice between only these two machines, I'd buy the 390 and dedicate 8GB DDR5 RAM to the GPU if possible, and 16GB to the CPU.

[Manfred M]

Robin - for the most part, Photoshop uses a bit of GPU power, but not too much (things like rotating the screen) and a few other functions. If you were looking at doing your own video, using Adobe's Premiere Pro, then the GPU upgrade might makes sense as GPU acceleration is used extensively there. As it is, most of the GPU specs are written around 3D gaming and getting reasonable frame rates. As you are not a gamer, the 2GB ram on the lower end GPU is going to be fine. The important bit is the OpenGL support, and any GPU I have looked at supports that. I kept my 4 year old graphics card when up built myself a new desktop and the I mostly use what you do (i.e. photo editing). I put 36GB of RAM on the MB and that works beautifully (up from 16GB on the old machine).

The other part is the processor itself. I just built a new desktop a couple of months ago and went for a 4-core i7 processor (gives me 8 virtual processors), because on desktops, this CPU supports multi-threading. Again, this is more important when running multi-threaded applications (Adobe Premiere Pro and Adobe After Effects fall into that category). I have the Skylake 6700 (nominal 3.4Ghz CPU) although it can run at 4.0GHz.

For me the biggest bang for the $$$ was the 1TB SSD I used for the system drive and the 256GB M2 drive that I use as a working drive when I edit. I've never found a great advantage to the hybrid drives as they do save a touch faster, but the read rate (unless you are pulling a buffered file) is the same as a standard HDD. The 256GB SSD being offered is quite small. I wouldn't go with anything less than 500GB, unless you just use it as a system drive.

Thunderbolt vs USB 3 - I'm not sure about the latest specs, but the last time I looked USB 3 was the faster of the two.

[Black Pearl]

Thanks

I could lift out the standard 8gb of RAM and replace it with 32GB of RAM (4x 8GB) for about £140 which might be a good investment as I have seen the RAM monitor on my current iMac display the limit a few times even with the max 16GB onboard.

I store very little on my current iMac hence the 256GB SSD option for the new one - all my images are on external drives with just day-to-day stuff and a bit of the wife's iTunes music internal. I have a 2TB NAS drive that stores all my media for playing music on the Hi-Fi and watching movies on our TV's via DNLA while all my mobile music is streamed via Apple Music these days as I have a completely unlimited data plan.

Unfortunately I can't stretch to an i7 and a 512MB SSD but if the general advice is i7 over i5 then I might go that route on the M390 2GB GPU model.

Thunderbolt over USB3 is still up in the air - TB2 is faster than USB3.1 at 20Gbps but I can't find much info as to how that translates to HDD use. I get the feeling the drive is the limit not the connection.

[billtils]

Robin

What Manfred says about the hybrid drives fits with the general view on the various mac Forums - all SSD is the best option, and the cost penalty has lessened substantially.

[Manfred M]

Thunderbolt over USB3 is still up in the air - TB2 is faster than USB3.1 at 20Gbps but I can't find much info as to how that translates to HDD use. I get the feeling the drive is the limit not the connection.

The SATA 3.2 spec allows for theoretical transfer rates of 16Gbps, and so far as I can tell only M.2 SSD drives come anywhere close to that (which is why I bought a MB that supports them and installed one; in real life I find it a bit faster than the regular SATA 3 SSD I use as my system drive). Mechanical drives probably top out at speeds well below what either Thunderbolt or USB 3 can handle, so in reality this is probably a moot point, based on how you use external data storage.

I did an unscientific test with my RAID unit and found little appreciable speed gain in using USB 3 over USB 2 ports. I suspect that comes down to both the drive speed and the RAID process on my external storage. I do use NAS as well and that is quite slow as I use a hard wired network for that, i.e. okay for backup, but I bring things across to my M.2 drive for editing work.

[Pippan]

Hi Robin, I've just done exactly what you're planning: replaced a mid 2010 27" i7 iMac with a brand new 5K. Went with the i7, 500Gb SSD, standard graphics card and upped the RAM myself from the basic 8Gb by adding 2 sticks of Crucial 16Gb to the spare slots (not cheap but a lot cheaper than Apple's RAM). Love it and it's very fast (btw despite what Apple's spec sheet says these new iMacs can run 64Gb RAM-mine now has 40). Maybe it's my poor eyesight but I'm less overawed with the 5K screen than I expected to be; nice but not a vast difference. I had to do something though as the HDD in the old one died and I run a business with it as well as doing photography as a hobby.

When I had time I got a Crucial MX300 750Gb SSD + adapter and 2 sticks of 8Gb RAM and put them in the old machine for my daughter (it's now at 20Gb RAM but can take up to 32). All up less than AU$500 and it now runs way better than it did when new. Doesn't get hot like it used to either (it used to run at 60-62C--I live in the tropics with no aircon). I mention this because if money's tight this might be a better value alternative to AU$4K for the new machine + $550 for the 32Gb RAM upgrade.

[Black Pearl]

Thanks for the reply.

I will add extra RAM myself - likely 2x 8GB at first to give 24BB then possibly later swap the two original 4GB sticks out for more if I feel the system needs it. I did read about the 64GB max but I can't see me ever needing that much. I think I can stretch to the slightly faster 3.3/3.9 i5 and still get a 512 SSD and a M395 GPU. I've had a clear-out on my current HDD and got the entire contents down to a little under 400GB so I can Time Machine everything over and still have a bit of wiggle room. I could get it lower but I'd need to start moving my wife 's iTunes and iPhoto libraries to external drives but if for any reason they weren't powered on and ready when she accessed her stuff there'd be hell to pay so I can't get it quite the way I would prefer

[charzes44]

So why don't you leave your wife's stuff on the old one, and let her use it exclusively?

[Black Pearl]

So why don't you leave your wife's stuff on the old one, and let her use it exclusively?

My eldest son is in need of a new computer for his studies so he's been promised it - that and we don't have space for two computers downstairs.

[charzes44]

My eldest son is in need of a new computer for his studies so he's been promised it - that and we don't have space for two computers downstairs.

Been there, done that!