Speed To Create, Capacity To Dream
Storage Wishlist…

64GB Memory Kit for 2017 iMac 5K Works Great: Save $760 vs Apple

View iMac 5K at B&H Photo and see also MPG’s computer gear wishlist. Not sure which Mac to get or how to configure it? Consult with MPG.

The OWC 64GB memory kit for the 2017 iMac 5K worked flawlessly for all the review testing of the 2017 iMac 5K.

It’s a no-brainer—order the 2017 iMac 5K with 8GB memory (not 16 or 32 or 64), and then order 64GB memory for iMac 5K from OWC for a savings of about $760*. OWC also has 32GB memory for the 2017 iMac 5K.

64GB OWC memory for 2017 iMac 5K

* At the time this was written, the upcharge at the Apple Store from 8GB to 64GB was $1400. OWC 64GB memory for 2017 iMac 5K was about $640, for a savings of a whopping $760. Apple’s memory prices are a poor value for customers, but a nice profit center for Apple.

64GB of OWC memory in 2017 iMac 5K

Photo and Mac Computer Deals of Note

Some crazy-good deals here and also deals on prime items:

See also:

Cycling

Get a 5K Display for only $1499 PLUS a FREE COMPUTER

A 5K Display for only $1499 which includes a free computer... well it’s true—it’s called the iMac 5K and I consider it the best display on the market today.

Apple 27" iMac 5K

$1499 Apple 27" iMac with Retina 5K Display (Late 2015) with free expedited shipping

While this model has the 1TB hard drive (no SSD), you can boot it off an SSD like the OWC Envoy Pro EX or some other OWC SSD. and store image files on the hard drive. Add 16 or 32 or 64GB memory from OWC and perhaps some big storage, and you’re 'good'.

Point is, you get a fantastic display with a very fast computer—it’s a no brainer for anyone on a budget. Great for a high school or college student too!

See also:

B&H Deal ZoneDeals by Brand/Category/Savings
Deals expire in 68 min unless noted. Certain deals may last longer.
$2299 SAVE $500 = 17.0% Canon EOS 5D Mark III DSLR in Cameras: DSLR
$2698 SAVE $300 = 10.0% Sony a7R II Mirrorless in Cameras: Mirrorless

Nifty Desk Fan that Runs on USB

This nifty OPOLAR 8 Inch Metal Desk Fan runs off USB power (through desktop or laptop or via any AC wall adapter with a USB port). It could also run a long time on a portable battery.

The OPOLAR 8 Inch Metal Desk Fan is nice and quiet on low, a little louder on high which moves a lot of air. Plus it has a three-speed switch: Off, Low, High—perfect so that it does not need to be unplugged.

I actually run two of the smaller 5-inch OPolar fans aimed at my Comcast router and UPS and couple of laptop servers, for those hot days in my garage—they help significantly.

The OPOLAR 8 Inch Metal Desk Fan is useful for a nice cool breeze in a hot room when working on a computer. I also plan using it as portable fan for my Sprinter photography adventure van on the road when parked where no A/C is operating. It’s small and light enough to just hang off the wall or whatever.

OPOLAR 8 Inch Metal Desk Fan runs off USB power
Blazing-fast PCIe storage for Mac Pro Tower

2017 iMac 5K: Connecting a Display Done Easily with OWC Thunderbolt 3 Dock

Mac wish list •  all 15" Apple MacBook Pro 2017 models •  MPG gets credit if you buy through those links.
MPG tested a fully-loaded 2017 MacBook Pro with 1TB SSD.
Suggested accessories include the OWC Thunderbolt 3 Dock, the 1TB Envoy Pro EX.

The 2017 iMac 5K utilizes Thunderbolt 3 / USB-C ports. These are not directly compatible with most displays (if any as of mid 2017), such as my workhorse NEC PA302W wide gamut professional display.

The Apple Thunderbolt 3 Male to Thunderbolt 2 Female Adapter is non-functional for connecting a display; it only passes data signals, not video. Thus to connect my NECPA3o2W wide gamut display, no adapter that Apple offers will work.

Enter the OWC Thunderbolt 3 Dock. Not only does it provide a Mini DisplayPort port for connecting the display, it provides a host of other ports as well, adding five USB-A ports in addition to the 4 USB-A ports on the iMac 5K itself.

See also 2016 MacBook Pro TESTED: 10-Bit Color With External Display in which I note that the OWC Thunderbolt 2 Dock also works—using the Apple adapter to adapt the 2016 MacBook Pro to the Thunderbolt 2 Dock.

iMac 5K using OWC Thunderbolt 3 Dock to connect via Mini DisplayPort to NEC PA302W wide gamut display
2017 MacBook Pro using OWC Thunderbolt 3 Dock to connect via Mini DisplayPort to NEC PA302W wide gamut display

Seen above, the OWC Thunderbolt 3 Dock neatly solves the display connectivity issue with its Mini DisplayPort port, charges the MacBook Pro, and provides gigabit ethernet and other ports, as shown.

OWC Thunderbolt 3 Dock port layout
ThunderBay 4 - The Speed To Create. The Capacity To Dream.
Storage Wishlist…

TESTED: BatPower USB-C High Speed In-Vehicle Charging of 2016/2017 MacBook Pro and 2015 MagSafe MacBook Pro Too!

The diminutive BatPower CPD 110W PD USB-C Car Charger for MacBook Pro plugs into the cigarrette lighter socket standard in vehicles to directly charge any MacBook Pro with USB-C ports (2016 and 2017 and later models, there is also a high power charger for earlier models).

What I did not realize initially was that BatPower also has the BatPower CCA 110W Laptop Car Charger for Macbook Pro, MacBook Air and MacBook (2006-2015 Mac laptops).

The difference is only which charging cable is plugged into the BatPower charger. So one handy little car socket charger can handle any MacBook or MacBook Pro from 2006 through 2017 models!

Read more...

  • Charges a MacBook Pro at 90 watts (the maximum) via USB-C port.
  • Two high power USB-A ports.
  • Total charging power of 110 watts.
  • The BatPower Laptop PD technology automatically detects and delivers 5V, 9V, 12V, 15V, 20V(Max90W), based on your devices needs.
  • Charges MacBook Pro and many other devices.
  • CPD Car Charger size: 3 inches (L) x 1.8 inches (W) x 1 inches (H) Weight: 3 ounces.
  • Packing list: BatPower CPD Car Charger Adapter, PD USB-C Converter, Type C Charging Cable, Instructions Manual.
  • Warranty: 30 days money back or exchange, free 18 months warranty. (Note: Sold by BatPower only).
 
BatPower CPD 110W PD USB-C Car Charger for either 2016/2017 MacBook/MacBook Pro or MagSafe models
OWC Thunderbolt 2 Dock
Review of Thunderbolt 2 Dock

My Sprinter Photography Adventure Van Project: Computers and Computer Desk

For the genesis of this project, see My Sprinter Photography Adventure Van Project.

The #1 key goal of my Sprinter photography adventure van is to be able to work as efficiently in the van up high in the mountains as I can at home. That means a computer desk with my wide gamut workhorse NEC PA302W 30" display, driven by an Apple iMac (preferred) or Apple Mac Pro or MacBook Pro, with battery power sufficient for two days. Along with OWC peripherals for storage and more. With that in place, I can shoot in the field and publish at downtime (bad light middle of the day, night, etc).

See Sprinter Van: Desk Computer Layout in my Sprinter photography adventure van section.

Below,the table as shown is just a rough mockup for the width I have available (about 44 inches) and depth (about 30 inches), using a real table I already have. The actual installed table might not even have an outer-left leg, or at least it will be inset more, with the inner legs bolted to the van wall to save space and for rigid support (I’ve asked for a table that supports 250 pounds). The front will be shaped in a way that allows ideal positioning and will also round-off the corners. Prior to the upfitting process though, an initial trial run with this rectangular table is what I'll use to check out the fit and placement of things. Then I will design just the curvature I want of the front edge of the table. The chair will of course by a quality swiveling chair, like the Herman Miller Aeron.

* Tip: solar is an expensive non solution the money being far better spent on a bigger battery, or a 2nd alternator or a underbody diesel generator.

Shown under the iMac 5K is the OWC Thunderbolt 3 Dock (highly recommended).

Lloyd Chambers' simulated photography working table for Sprinter photographic adventure van
S
Blazing-fast PCIe storage for Mac Pro Tower

2016/2017 MacBook Pro or 2017 iMac 5K: Connecting a Display Done Easily with OWC Thunderbolt 3 Dock

Mac wish list •  all 15" Apple MacBook Pro 2017 models •  MPG gets credit if you buy through those links.
MPG tested a fully-loaded 2017 MacBook Pro with 1TB SSD.
Suggested accessories include the OWC Thunderbolt 3 Dock, the 1TB Envoy Pro EX.

See the MPG review of the 2017 Macbook Pro.

The 2017 MacBook Pro utilizes Thunderbolt 3 / USB-C ports. These are not directly compatible with most displays, such as my workhorse NEC PA302W wide gamut professional display.

The Apple Thunderbolt 3 Male to Thunderbolt 2 Female Adapter is non-functional for connecting a display; it only passes data signals, not video.

Enter the OWC Thunderbolt 3 Dock. Not only does it provide a Mini DisplayPort port, it provides a host of other ports as well, eliminating the dongle mess.

2016 MacBook Pro using OWC Thunderbolt 3 Dock to connect NEC PA302W wide gamut display

Seen above, the OWC Thunderbolt 3 Dock neatly solves the display connectivity issue with its Mini DisplayPort port, charges the MacBook Pro, and provides gigabit ethernet and other ports, as shown.

OWC Thunderbolt 3 Dock port layout
OWC Thunderbolt 2 Dock
Review of Thunderbolt 2 Dock

2017 MacBook Pro vs My 2015 MacBook Pro

Mac wish list •  all 15" Apple MacBook Pro 2017 models •  MPG gets credit if you buy through those links.
MPG tested a fully-loaded 2017 MacBook Pro with 1TB SSD.
Suggested accessories include the OWC Thunderbolt 3 Dock, the 1TB Envoy Pro EX.

The 2017 MacBook Pro top-end laptop sits here on my desk on loan from B&H Photo. Next to it is my trusty top-end 2015 MacBook Pro.

As the tests show, the 2017 Apple MacBook has little to offer in terms of performance over the 2015 MacBook Pro.

But beyond performance, I prefer my 2015 MacBook Pro:

  • Keyboard on 2015 model vastly better for my typing, versus the chiclet keyboard on the 2017.
  • Trackpad on the 2017 is so large as to be a nuisance.
  • The touchbar remains a useless nuisance.
  • The dongle hassle with the 2016/2017 MacBook Pro is as problematic as ever; the OWC Thunderbolt 3 Dock is highly recommended (picture below).
  • Strange performance hiccups with the 2017 model, but never with the 2015.

Put another way: if it were a free exchange (217 for 2015), I’d keep my 2015 MacBook Pro. It’s just better for my usage, and with the BatPower charger for my car (for 2016/2017 or for 2015/2014/2013), the charging issue of USB-C vs older models is a moot point.

Check OWC used Macs for great deals on used Macs, for example used 2014/2015 MacBook Pro at OWC. The 2014 MacBook Pro is little different from the 2015.

B&H Photo still has new 2015 MacBook Pro models for sale, I recommend 512GB SSD (1TB better but they may be out). But I think buyers are better off getting MacBook Pro with 1TB SSB from OWC.

Thunderbolt 3 Dock for 2016 or 2017 MacBook Pro

If going with the 2016 or 2017 MacBook Pro, the OWC Thunderbolt 3 Dock has been a godsend in hooking up the 2017 MacBook Pro for desktop use (not for out and about, as it requires AC power). Comparing to the cost of a bag full of adapters, its cost is less than it seems, and its functionality much more convenient.

OWC Thunderbolt 3 Dock port layout

Eric L writes:

Thank you for your exhaustive comparisons.

I owned a 2015 15" MBP max specs but sold it because it was too noisy: I like a quiet environment, especially when watching a movie (VLC) or more importantly listen to music (real top hifi).

I also own a 2015 13"MBP: less noisy (though fans kick in fast with VLC app), but Summer in Japan is quite hot and sooner or later the fans rotate faster. What about your experience with the 2017 models? I'm sacrificing speed for silence, I already sold a 5K iMac as well. Fan is OK, but not permanently.

MPG: the 2017 MacBook Pro is much more quiet than the 2015 model.

Robin K writes:

Lloyd, first just a general comment thanking you (again) for your excellent investigative reports. I did buy a 2016 MBP, but returned it shortly after purchase. Hated the keyboard. And I found that my 2012 model was not that much less powerful. So I bought a basic 2015 model - it's terrific. Keep up the good work.

MPG: a common sentiment regarding the keyboard.

OWC Easy SSD Upgrade Guide
MacBook Pro and MacBook Air
iMac, Mac Pro, MacMini, more!

Up to $500 off MacBook Pro At B&H Photo

B&H Photo has up to $500 off Macs. I recommend sticking with models that have 16GB memory.

OWC Thunderbolt 2 Dock
Review of Thunderbolt 2 Dock

Can Companies Like Apple and Facebook and Google do Business in China Ethically?

The Wall Street Journal in China’s Stopchat: Censors Can Now Erase Images Mid-Transmission reports:

BEIJING—China’s already formidable internet censors have demonstrated a new strength—the ability to delete images in one-on-one chats as they are being transmitted, making them disappear before receivers see them.

The ability is part of a broader technology push by Beijing’s censors to step up surveillance and get ahead of activists and others communicating online in China.

Displays of this new image-filtering capability kicked into high gear last week as Chinese dissident Liu Xiaobo lay dying from liver cancer and politically minded Chinese tried to pay tribute to him, according to activists and a new research report.

...

The future of AI (artificial intelligence) is there in plain sight.

The disease of our time is that so-called journalists report on events but are rabidly silent on even rudimentary implications—reporting concretized facts devoid of any conceptual understanding of the implications of those facts/events. Real news, fake intellect.

Can a company like Facebook or Apple or Google or Yahoo ever do business in China without giving their implicit sanction and support to a repressive government which lacks any concept of individual rights? Not speaking out against an evil means supporting it. Yet these companies pander to any dubious statistical allegation of workplace unfairness. Silence speaks volumes, but apparently profits speak louder. Ethics do not have a price, nor can one engage thugs or repressive regimes on any intellectual basis—only brute force is understood, or at the least, refusing to deal. The hypocrisy in objecting to our own government’s policies but remaining silent with repressive countries lays bare the ethical vaccum. Combine that ethical vaccum with AI and the future looks dystopian.

Here in the USA, Google finally stopped spying on user email for marketing/sales purposes. Ponder that versus the “don’t be evil” Google motto long ago abandonded.

USB-C Dock for MacBook

4 USB3 ports, 1 USB-C port, SD card reader, gigabit ethernet, audio ports, HDMK 4K port!

2017 MacBook Pro: IntegrityChecker Verify

Mac wish list •  all 15" Apple MacBook Pro 2017 models •  MPG gets credit if you buy through those links.
MPG tested a fully-loaded 2017 MacBook Pro with 1TB SSD.
Suggested accessories include the OWC Thunderbolt 3 Dock, the 1TB Envoy Pro EX.

See the MPG review of the 2017 Macbook Pro.

The 2017 MacBook Pro performs very well when a highly optimized program like diglloydTools IntegrityChecker is run.

2017 MacBook Pro: IntegrityChecker Verify

The remarkably sluggish 2013 Mac Pro suffers mightily from its aging SSD which is about 1/3 the speed of the 2017 and 2015 Macs—the Mac Pro is I/O bound.

IntegrityChecker verify 209000 files totaling 159.3 GB
ThunderBay 4 - The Speed To Create. The Capacity To Dream.

2017 iMac 5K: XCode Build C++ Project

View iMac 5K at B&H Photo and see also MPG’s computer gear wishlist. Not sure which Mac to get or how to configure it? Consult with MPG. MPG gets credit if you buy through those links.

See the MPG review of the 2017 iMac 5K.

This test uses all CPU cores, which implies an easy victory for the 2013 Mac Pro with its 8 CPU cores, versus the 4 CPU cores of the iMac 5K. But it is not so: the 4-core 2017 iMac 5K 4.2 GHz sails to a clear-cut victory over the 8-core Mac Pro.

2017 iMac 5K: XCode Build C++ Project

SSD speed matters for this test, as does clock speed.

XCode build time for C++ project
OWC Thunderbolt 2 Dock
Review of Thunderbolt 2 Dock

2017 MacBook Pro and 2017 iMac 5K: Convert 50-Megapixel CR2 Raw to JPEG

Mac wish list •  all 15" Apple MacBook Pro 2017 models •  MPG gets credit if you buy through those links.
MPG tested a fully-loaded 2017 MacBook Pro with 1TB SSD.
Suggested accessories include the OWC Thunderbolt 3 Dock, the 1TB Envoy Pro EX.

See the MPG review of the 2017 Macbook Pro.

2017 MacBook Pro: Convert 50-Megapixel RAW Files to JPEG (Adobe Camera Raw)

Speed of various Macs saving 50 megapixel raw files as JPEG
OWC Easy SSD Upgrade Guide
MacBook Pro and MacBook Air
iMac, Mac Pro, MacMini, more!

2017 MacBook Pro: Text Search with grep Versus Other Macs (SSD Speed + CPU Speed)

Mac wish list •  all 15" Apple MacBook Pro 2017 models •  MPG gets credit if you buy through those links.
MPG tested a fully-loaded 2017 MacBook Pro with 1TB SSD.
Suggested accessories include the OWC Thunderbolt 3 Dock, the 1TB Envoy Pro EX.

See the MPG review of the 2017 Macbook Pro.

Be careful what you wish for, because small I/O speed is usually much more important than the peak speed for very large transfers.

2017 MacBook Pro: Grep (Search)

The 2017 MacBook Pro is slower than the 2015 MacBook Pro in this test, just as the 2017 iMac 5K is slower than the 2015 iMac 5K. Seems like Apple has made a change to SSDs that degrades small I/O performance, just as measured by DiskTester in the SSD Speed vs Transfer Size.

Speed of grep textual search
SSD Upgrade for MacBook Pro Retina
Internal SSD Wishlist…

Apple Core Rot: Networking Problems (NFS, Failure to Copy Files, More)

Just yesterday I observed a nasty networking bug in macOS Sierra: the Finder completed the copy of one folder witih one file and one subfolder (a Lightroom catalog folder), but failed to copy a critical file (a Lightroom catalog file)—nasty bug there. I have seen that before (prior to Sierra) and it is deeply disturbing and why using Integrity Checker is a smart move. I had to try again—and then it worked.

Other bugs include:

  • MacOS Sierra wants to mount my Scratch volume as read-only on my other Macs, even though I connect and login as myself. This never happened in prior OS versions. I am forced to use Ignore permissions on this volume to work around the problem.
  • Large copies with many files using the Finder fail almost all of the time with errors about the file already existing. They never with 'cp' at the command line. Such a basic function—and it cannot be used.

Nigel S writes:

I discovered your blog posts on "Apple Core Rot" awhile back after having experienced some of these issues for myself. Since recently "upgrading" to Sierra, I believe I've run into an issue you've yet to document on your site, this one regarding NFS permissions.

Where I work we use a Vagrant/VirtualBox VM for local web development. Part of this environment is the "shared folder" that is mounted in the VM from the host machine. In order to avoid a major performance loss with web apps on the share, it is necessary to use NFS with file system caching enabled. With the upgrade to Sierra, it is now impossible to modify or delete many files from inside the guest VM below the root of the share. Use of bindfs or chmod from the guest have no effect whatsoever. The only workaround is to delete the file from the host or run a command to refresh all NFS links.

Needless to say, this is a major barrier to productivity as even a simple compile of CSS to Sass fails with a permission denied error. More details about the issue on the Vagrant project here: https://github.com/mitchellh/vagrant/issues/8061. According to the most recent comment there, an issue has been filed with Apple for months with no action taken. Of course, one of the reasons we use Apple hardware and software in the first place is because shared folders have a whole different set of permission issues on Windows! Just another example that suggests Apple is no longer interested in supporting developer users of their platform. Thank you for continuing to document this unfortunate trend.

MPG: the lack of attention to detail these days at Apple QA should be deeply disturbing to anyone using the macOS platform for work.

In my experience, Apple takes weeks to months to even look at a bug report, let alone do anything about it. The bugs I have filed have been ignored, nothing done. I‘ve given up wasting my time with Apple bug reporter; there is no adult in charge from what I can tell.

SSD Upgrade for MacBook Pro Retina
Internal SSD Wishlist…

Apple Bug? 2017 MacBook Pro Has Impaired Performance Using Apple Power Brick vs OWC Thunderbolt 3 Dock + Why Does 800% CPU Usage Go Into Idle Clock Speed Mode?

Mac wish list •  all 15" Apple MacBook Pro 2017 models •  MPG gets credit if you buy through those links.
MPG tested a fully-loaded 2017 MacBook Pro with 1TB SSD.
Suggested accessories include the OWC Thunderbolt 3 Dock, the 1TB Envoy Pro EX.

I came across a curious thing: when measuring power usage for the 2017 MacBook Pro, I found that the total power draw at 800% CPU usage was 58 watts with the OWC Thunderbolt 3 Docks, but only 24 watts with the Apple power brick. The OWC TB3 Dock did not even get warm even aas the MacBook Pro ran its fan much louder and got much hotter than when powered by the Apple power brick!

How could this be that there is 2.5X increased power draw with the OWC TB3 Dock? MemoryTester is part of diglloydTools; its stress command shows memory bandwidth as it runs.

What it confirms is that the OWC Thunderbolt 3 Dock somehow persuades the 2017 MacBook Pro to run at higher performance! Surely this is an Apple bug of some kind related to the disappointing performance; see 2017 MacBook Pro: Severely Degraded Performance for More than Short Usage (and also applies to 2016 MBP).

Power draw will vary by application load and the Thunderbolt 3 Dock doesn't cause the MacBook Pro to draw more*, but it appears that the OWC Thunderbolt 3 Docks enables higher performance versus the Apple power brick. Since the Apple power brick is rated at 85 watts this is a strange finding; it suggests an Apple power management bug.

* Measured power draw of the OWC Thunderbolt 3 Dock is about 11 watts when the MacBook Pro is idle.

Lower performance with the Apple power brick is consistent with but does not fully explain the performance drop under load seen in prior tests. It suggests an Apple power management bug that throttles performance with the Apple power brick, but not the OWC Thunderbolt 3 Dock.

Supporting this contention are the following:

  • Performance (memory bandwidth) is higher by 8.5% using the OWC Thunderbolt 3 Dock.
  • A this higher performance the MacBook Pro gets hotter (determined by feeling bottom of the MBP case), and runs its fans at an higher/louder level—the difference is easy to hear.
  • Swapping the OWC TB3 cable out for the Apple-supplied cable immediately droppedthe TB3 Dock power usage by 10 watts, and produced the same lower performance as with the Apple power brick. The Apple cable is useless for the Dock as well, since it is not a TB3 cable (system message pops up saying can't use Thunderbolt).
  • OWC TB3 cable on Apple power brick also delivers the lower performance. So it seems that the *both* the Apple power brick and its cable suck.

Tests were repeated half a dozen times, swapping the power sources into the same port on the MacBook Pro—100% repeatable. At this time, there is no evidence that Photoshop and other benchmarks and/or IntegrityChecker will run faster with OWC Thunderbolt 3 Dock power. But the differing memory bandwidth and power draw are 100% reproducible every time the power source is switched. Strange. Reader Jeffrey L suggests Intel’s Power Gadget tool.

Memory bandwidth varies by power source in 2017 MacBook Pro: Apple power brick vs OWC Thunderbolt 3 Dock
Figures obtained using diglloydTools MemoryTester

Clock speed drop to about 1.8 GHz

Check out these two graphs, obtained via the Intel Power Gadget.

Running the verify command in IntegrityChecker (part of diglloydTools), all 8 virtual CPU cores were running full tilt (800% CPU usage or close to it). As the test started, power consumption rose sharply to 72 watts, then declined. The reason becomes clear from the graphs below.

The graphs raise more questions than they answer. In particular, why does a 3.2 GHz CPU (turbo boost to 3.6 GHz) suddenly plumet to about 1.8 GHz and stay there for a long time? And why at other times does it stick nicely at 3.6 GHz?

From what I can tell, there is some kind of performance bug in which macOS takes the CPU speed down to 1.8 GHz or so even when 800% CPU usage is constant. That behavior is seen in the two leftmost graphs. For the graph at right, the dip is an end to the job and some idle time, then the job is repeated. Note that clock speed when idle is similar to clock speed under 800% CPU load! This would explain the weird sluggishness that I’ve experienced all too often with the 2016 and 2017 MacBook Pro—strange sluggish pauses. That would make sense if the CPU clock speed were throttled down to half speed or so.

There is another possible explanation, but it’s a guess: could it be that the clock speed is dropp during the MemoryTester stress command because memory bandwidth won’t support any faster execution speed? That would make sense: 8 virtual CPUs running on a 2133 MHz memory bus. Some techo-nerd out there might be able to confirm that as a theory. Reader Greg writes that it might have to do with introduction of Intel SpeedShift.

   
2017 MacBook Pro 3.2 GHz CPU clock speed drops from 3.6 to 1.8 Ghz, as per Intel Power Gadget

 

ThunderBay 4 - The Speed To Create. The Capacity To Dream.
Storage Wishlist…

Adobe Lightroom Performance: Inefficiencies Could be Fixed

View iMac 5K at B&H Photo and see also MPG’s computer gear wishlist. Not sure which Mac to get or how to configure it? Consult with MPG.

Testing Adobe Photoshop Lightroom (or Photoshop) often shows modest speed gaps between computers that ought to diverge more strongly, e.g., an 8 core system runs only 20% faster than a 4 core system—or more slowly.

This thread at Adobe asks for performance suggestions. I could take days and speak to any number of issues in Lightroom and Photoshop, but this post will be my contribution—being an unpaid consultant pays no bills.

Some of the unharvested speed potential seen in applications is due to clock speed differences (e.g., 3.5 vs 4.2 GHz), but that is not enough to explain why 6 or 8 or 10 or 12 cores run only marginally faster than 4 cores.

Speaking in general, here are just a few reasons that speed is not faster on machines with more CPU cores (these comments are not about Adobe software, but many do apply in at least some cases):

  • Serializing I/O with computation
  • Serializing computational steps that could run in parallel.
  • Failure to use more than one CPU core at all. Or at certain steps of the computation, thus creating a choke point that limits peak speed.
  • Busy waiting (Topaz InFocus with 2 cores = 12 cores due to this severe bug).
  • Failing to use large enough memory buffers for disk I/O or other purposes.
  • Allocating and disposing of memory at high frequency, instead of maintaining a cache.
  • Failing to cache computational results that can be re-used.
  • Inappropriate queuing mechanisms or simply a lack not using job or I/O queues.
  • Using less than optimal algorithms e.g., an O(n^2) algorithm instead of an O(nLog(n)) algorithm, even for a short while, creating choke points that throttle performance.
  • Failure to do obvious things, like process 8 files in parallel on an 8 core CPU, together with appropriate I/O queues.

The reason for impaired performance that does not scale on machines it ought to is algorithmic inefficiency, that is, a failure optimize the computational process and even a failure to take trivially easy steps, like using appropriate I/O sizes for exploiting the full speed of today’s flash drives (SSDs). If Adobe did the job better, we’d all get a free speed boost.

I was a professional software engineer for 35 years, and I’ve optimized code for more years than some of today’s programmers have been out of diapers. I’ve learned many things about single and highly multi-threaded performance during that time in a variety of languages, including how few programmers have no concept of big-O notation or algorithmic efficiency. That said, I have to believe that Adobe has numerous highly talented engineers that could greatly improve performance.

Shown below is CPU usage during an Export job (see the test results). Notice how there is a regular spiky dip or valley in the CPU usage, indicating that the CPU cores go idle on a periodic basis.

Checking Activity Monitor as well as a Watts Up electricity meter, these dips appear to correspond to I/O activity. Even though the iMac 5K SSD is very fast, there are at least two reasons the CPU cores are forced to idle:

  • Lightroom appears to serialize I/O with computation (akin to stop lights smack dab in the interstate highway) instead of using separate work queues and an I/O read-ahead queue and an I/O write queue. The result is that CPU cores are forced to idle while waiting for I/O to complete. That’s a beginner mistake in my book.
  • While the iMac 5K SSD is very fast, its speed is only half of its peak speed up to 2MB I/O sizes, that is, I/O sizes of 64MB or so are required for maximum seed. And yet Lightroom apparently never uses I/O sizes larger than 1MB, thus cutting the peak I/O speak to less than half of what is possible. See the iostat figures further below. So the I/O takes more than double the time necessary and it is apparently serialized with computation.

The I/O speed thing is a trivial fix: at the least, read the raw file in a single read—that’s a no-brainer. Then use I/O queues for both input and input (hard to do but not very hard).

CPU usage during Lightroom Export
2017 iMac 5K

What iostat shows about Lightoom I/O

The iostat results show that Lightroom never performs I/O in sizes larger than 1MB, which means using less than half the speed potential of the SSD.

Half-speed I/O creates a choke point that manifests in the failure of an 8-core 3.3 GHz Mac Pro to run more than modestly faster than a 4-core 4.2 GHz iMac 5K, indeed, slower for an Import operation. How much the I/O is the issue cannot be easily told, but it is surely a factor and those running hard drive of Fusion drive will be impacted much more severely.

As a crude measure of CPU cores and clock speed:

8 * 3.3 = 26.4 GHz of CPU core = 1.57X more cycles (but slower SSD)
4 * 4.2 = 16.8 GHz of CPU core

iMac:DIGLLOYD lloyd$ iostat -dK -w 1
disk0 
KB/t  tps  MB/s 
298.59   13  3.79 
88.00    3  0.26 
4.00    2  0.01 
0.00    0  0.00 
18.00    4  0.07 
32.00    1  0.03 
72.00    2  0.14 
8.00    1  0.01 
29.00    4  0.11 
932.42  122 111.54 
197.87  395 76.31 
8.00    2  0.02 
0.00    0  0.00 
28.00    6  0.16 
8.00    3  0.02 
4.00    2  0.01 
30.05   39  1.14 
64.62   13  0.82 
36.00    1  0.03 
12.71   56  0.69 
disk0 
KB/t  tps  MB/s 
686.95  198 132.81 
880.80   30 25.67 
6.67    3  0.02 
4.00    2  0.01 
5.78    9  0.05 
4.00    1  0.00 
0.00    0  0.00 
28.00    3  0.08 
17.33    3  0.05 
0.00    0  0.00 
1024.00   32 31.96 
907.16  151 134.06 
30.00    2  0.06 
4.80    5  0.02 
8.00    3  0.02 
4.00    1  0.00 
4.00    1  0.00 
8.00    1  0.01 
256.00    1  0.25 
0.00    0  0.00 
disk0 
KB/t  tps  MB/s 
14.23   95  1.32 
782.66  165 125.97 
917.48   62 55.53 
5.00    4  0.02 
0.00    0  0.00 
5.60    5  0.03 
4.00    1  0.00 
4.00    1  0.00 
6.00    2  0.01 
4.00    1  0.00 
1024.00   24 23.97 
628.74  129 79.11 
904.27   89 78.50 
988.57    7  6.75 
6.00    2  0.01 
4.00    1  0.00 
0.00    0  0.00 
4.00    1  0.00 
256.00    2  0.50 
0.00    0  0.00 

Well optimized

Below, this is what one ought to see with a well optimized program that is CPU intensive. Note the lack of any dropouts in CPU usage. The graph is from an IntegrityChecker verify invocation (IntegrityChecker is part of diglloydTools).

CPU usage during Lightroom Export
2017 iMac 5K

 

ThunderBay 4 - The Speed To Create. The Capacity To Dream.

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